refactor!: replace pack! macros with derive-based pipeline types

Remove the `pack!`, `pack_err!`, `pack_structural!`, and
`pack_err_structural!` macros, replacing all pipeline type definitions
with `#[derive(Grouped)]` and `#[derive(Grouped, Wrap)]` attributes.
This changes the generated struct shape from named-field structs with an
`inner` field to tuple structs accessed via `.0`, and removes the
auto-generated `name` and `info` fields from error types.

101 files changed, 1229 insertions, 2428 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea71a92..62b1f7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -301,6 +301,54 @@ None
 
     _Behavioral note:_ the `picked` values, flag parsing semantics, and the "longest registered prefix wins" matching rule are all preserved by the `picker` feature's `arg-picker` API. The removal is purely a dead-code cleanup: the legacy built-in parser has been fully superseded by `picker`, and downstream code must migrate to the new API names described above.
 
+5. **[`macros`]** **[BREAKING REMOVAL]** Removed the `pack!`, `pack_err!`, `pack_structural!`, and `pack_err_structural!` macros and replaced all pipeline type definitions with `#[derive(Grouped)]` (and, where applicable, `#[derive(Grouped, Wrap)]`) on user-defined structs.
+
+    ### What changed
+
+    The `pack!` family of macros — which generated a wrapper struct with a fixed `inner` field and a suite of trait impls (`From`/`Into`, `AsRef`/`AsMut`, `Deref`/`DerefMut`, conditional `Default`, `Grouped`, and `Into<AnyOutput>`/`Into<ChainProcess>`) — has been removed. Pipeline types are now defined directly as ordinary Rust structs annotated with the `Grouped` derive macro, optionally combined with `Wrap` for the ergonomic trait impls previously provided by `pack!`.
+
+    **Removed API:**
+
+    - **`mingling::macros::pack!`** — Removed entirely (both the `pack`/`pack` and `pack`/`pack_structural` re-exports and the underlying macro implementations).
+    - **`mingling::macros::pack_err!`** — Removed (extras feature).
+    - **`mingling::macros::pack_structural!`** — Removed (structural_renderer feature).
+    - **`mingling::macros::pack_err_structural!`** — Removed (structural_renderer + extras features).
+    - _*All `pack`* re-exports_* from `mingling::prelude` and `mingling::macros` — removed.
+    - **`mingling_macros` implementation modules** — Deleted `func/pack.rs`, `func/pack_err.rs`, `func/pack_structural.rs`, `func/pack_err_structural.rs`, and `systems/structural_data.rs`.
+    - **`mingling_pathf::patterns::PackPattern`** — Removed from `pattern_analyzer::init()` and the `patterns` module (both the `patterns/pack.rs` file and its `pub use pack::*;` re-export).
+    - **Pathf test asset** — Deleted `mingling_pathf/test/src/test_files/test_pack.rs` and the `test_pack_analyze` test in `mingling_pathf/test/src/lib.rs`.
+    - **`mingling/src/docs/lib.md` / `mingling/src/example_docs.rs`** — The `example_pack_err` doc module (and the corresponding `examples/example-pack-err/` example) were removed (Cargo.toml, Cargo.lock, src/main.rs, page.toml, test.toml, and the `examples.json` entry).
+    - **`docs/pages/other/features.md`** — The `pack_err!` row and detailed section were removed in favor of a "Declaring Error Types" section documenting `#[derive(Grouped, Default)]` (unit form) / `#[derive(Grouped, Wrap)]` (typed form).
+    - **`docs/_zh_CN/pages/other/features.md`** — Same changes as the English `features.md`.
+    - **`mingling/src/gen_program.rs`** — Doc comments updated from "created by the `pack!` macro" to "generated by the `gen_program!` macro" for `Entry`, `ErrorRendererNotFound`, `EntryFallback`, and `CompletionContext`. The "You can register it using `with_dispatcher`" doc on `CMDCompletion` was removed (since `with_dispatcher` no longer exists). The "and many others" phrase in the `macros` module doc was trimmed to remove `pack!` and friends.
+
+    **Migration guide:**
+
+    | Old `pack!`-family macro usage             | New equivalent                                                                            |
+    | ------------------------------------------ | ----------------------------------------------------------------------------------------- |
+    | `pack!(TypeName = Inner);`                 | `#[derive(Grouped, Wrap)] pub struct TypeName(Inner);`                                    |
+    | `pack!(TypeName = (A, B));`                | `#[derive(Grouped, Wrap)] pub struct TypeName((A, B));`                                   |
+    | `pack!(TypeName = ());` (unit)             | `#[derive(Grouped, Wrap, Default)] pub struct TypeName(());`                              |
+    | `pack_err!(ErrorName);` (simple)           | `#[derive(Grouped, Default)] pub struct ErrorName;`                                       |
+    | `pack_err!(ErrorName = Inner);` (typed)    | `#[derive(Grouped, Wrap)] pub struct ErrorName(Inner);`                                   |
+    | `pack_structural!(TypeName = Inner);`      | `#[derive(serde::Serialize, StructuralData, Grouped, Wrap)] pub struct TypeName(Inner);`  |
+    | `pack_err_structural!(ErrorName);`         | `#[derive(serde::Serialize, StructuralData, Grouped, Default)] pub struct ErrorName;`     |
+    | `pack_err_structural!(ErrorName = Inner);` | `#[derive(serde::Serialize, StructuralData, Grouped, Wrap)] pub struct ErrorName(Inner);` |
+
+    Behavioral differences to note when migrating:
+
+    - **Field access** — The old `pack!` types exposed a `pub inner` field. The new `#[derive(Grouped, Wrap)]` types are tuple structs whose single field is accessed as `.0` (or `.0.0` / `.0.1` when the inner type is itself a tuple, e.g. `(String, String)`). All internal call sites and examples were updated accordingly (e.g. `StateConfigEdit((String, String))` now accesses `kv.0.0` / `kv.0.1`, `StatePkgEnable((String, String))` accesses `p.0.0` / `p.0.1`).
+    - **Constructor** — `TypeName::new(inner)` becomes `TypeName(inner)`. `Dispatcher::begin` now constructs the entry as `#pack(args)` instead of `#pack::new(args)`.
+    - **`name` field / `info` field** — `pack_err!`'s auto-generated `name: String` field (snake_cased at compile time) and `info: Type` field are gone. Unit errors use `#[derive(Grouped, Default)]` and are constructed as plain unit values (`ErrorFoo`), while typed errors wrap their payload as `.0` (accessed as `err.0` instead of `err.info`).
+    - **`Default`** — `pack!`'s `Default` was conditional on the inner type. The new `#[derive(Grouped, Wrap, Default)]` requires the inner type to also impl `Default`; for unit-like errors use `#[derive(Grouped, Default)]` (a plain unit struct).
+    - **`AsRef` / `AsMut`** — The `Wrap` derive generates `Deref`/`DerefMut`, `From`, and `Into` but not `AsRef`/`AsMut`. Code relying on `AsRef`/`AsMut` from `pack!` should switch to `Deref` (`*value`) or field access.
+    - **Structured output** — `pack_structural!` / `pack_err_structural!` auto-derived `serde::Serialize` and `StructuralData`. The new equivalent requires adding `#[derive(serde::Serialize, StructuralData, ...)]` explicitly (and `use mingling::StructuralData;` when needed).
+    - **`register_type!`** — Both `Grouped` and `Wrap` derives invoke `register_type!` internally, so no separate registration call is needed.
+
+    **Examples of internal updates in this release** (all files updated from `pack!`/`pack_err!`/etc. to the derive-based form): `examples/example-argument-picker`, `examples/example-async-support`, `examples/example-basic`, `examples/example-combine-pathf-dispatch-tree`, `examples/example-combine-pathf-metadata`, `examples/example-command-macro`, `examples/example-completion`, `examples/example-error-handling`, `examples/example-exitcode`, `examples/example-hook`, `examples/example-lazy-resources`, `examples/example-metadata`, `examples/example-outside-type`, `examples/example-panic-unwind`, `examples/example-pathfinder`, `examples/example-repl-basic`, `examples/example-setup`, `examples/example-structural-renderer`, `examples/example-unit-test`, `examples/full-todolist`, `mingling_cli/src/config/cmd_cfg.rs`, `mingling_cli/src/lib.rs`, `mingling_cli/src/linter/cmd_explain.rs`, `mingling_cli/src/linter/cmd_lint.rs`, `mingling_cli/src/linter/mlint_report.rs`, `mingling_cli/src/metadata/cmd_metadata.rs`, `mingling_cli/src/pkg_mgr.rs`, `mingling_cli/src/pkg_mgr/cmd_install.rs`, `mingling_cli/src/pkg_mgr/cmd_internal_loadpkgs.rs`, `mingling_cli/src/pkg_mgr/cmd_pkg_disable.rs`, `mingling_cli/src/pkg_mgr/cmd_pkg_enable.rs`, `mingling_cli/src/pkg_mgr/cmd_pkg_show.rs`, `mingling_cli/src/pkg_mgr/cmd_uninstall.rs`, `mingling_cli/src/proj_mgr/cmd_class_add.rs`, `mingling_cli/src/proj_mgr/cmd_proj_init.rs`, the `dispatcher!` / `entry!` / `gen_program!` / `program_comp_gen!` / `program_fallback_gen!` / `program_final_gen!` macro implementations, `mingling_macros/src/func/dispatcher_clap.rs`, `mingling/src/example_docs.rs`, `mingling/src/docs/lib.md`, `README.md`, `GETTING-STARTED.md`, and all docs pages / tests listed above.
+
+    _Behavioral note:_ the runtime semantics of pipeline types are unchanged — `#[derive(Grouped, Wrap)]` produces types with the same `Grouped` identity, `Into<AnyOutput>`/`Into<ChainProcess>` routing, `Deref`/`DerefMut`, and `From`/`Into` conversions that `pack!` provided. The removal is purely an API move from magic macros to standard Rust derives, reducing macro surface area and making pipeline types inspectable and composable like any other struct.
+
 ---
 
 ## Contents
diff --git a/GETTING-STARTED.md b/GETTING-STARTED.md
index c1b8e25..0730136 100644
--- a/GETTING-STARTED.md
+++ b/GETTING-STARTED.md
@@ -66,23 +66,24 @@ The `#[chain]` attribute turns a plain function into an execution step. Think of
 ```rust
 dispatcher!("greet", EntryGreet);
 
-pack!(ResultGreeting = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     let greeting = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultGreeting::new(greeting).into()
+    ResultGreeting(greeting).into()
 }
 ```
 
 Key points:
 
 - The return type is `Next` — a type alias for `ChainProcess<ThisProgram>`.
-- You chain results by calling `.to_chain()` on any `pack!`-ed type.
+- You chain results by calling `.to_chain()` on any type defined with `#[derive(Grouped)]`.
 - You can have **multiple chain functions** for the same command, each transforming the data further.
 - With the `async` feature, chain functions can be `async fn`.
 
@@ -93,11 +94,11 @@ Key points:
 The `#[renderer]` attribute turns a function into an output handler. It receives the final result of a chain and returns a `RenderResult`.
 
 ```rust
-use mingling::macros::pack;
 use mingling::prelude::*;
 use std::io::Write;
 
-pack!(ResultGreeting = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
 
 #[renderer]
 fn render_greeting(greeting: ResultGreeting) -> RenderResult {
@@ -132,7 +133,8 @@ Mingling provides a **Picker** for argument extraction. You can use `pick()` or
 ```rust
 // Features: ["picker"]
 dispatcher!("greet", EntryGreet);
-pack!(ResultGreeting = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
@@ -140,7 +142,7 @@ fn handle_greet(args: EntryGreet) -> Next {
         .pick(&arg![String])                   // positional argument: first string
         .pick_or(&arg![repeat: u8, 'r'], || 1) // optional flag with default value
         .unwrap();
-    ResultGreeting::new(format!("{} x{}", name, count)).into()
+    ResultGreeting(format!("{} x{}", name, count)).into()
 }
 ```
 
@@ -195,7 +197,8 @@ With the `comp` feature, Mingling provides a fully dynamic completion system. Yo
 use mingling::{macros::suggest, ShellContext, Suggest};
 
 dispatcher!("greet", EntryGreet);
-pack!(ResultName = (u8, String));
+#[derive(Grouped, Wrap)]
+pub struct ResultName((u8, String));
 
 #[completion(EntryGreet)]
 fn complete_greet(ctx: &ShellContext) -> Suggest {
@@ -268,29 +271,34 @@ fn complete_lang(_: &ShellContext) -> Suggest {
 
 ## 7. Error Handling
 
-Mingling doesn't use `?` operator propagation. Instead, errors are just **alternative results** that flow through the same chain/render pipeline. Create error types with `pack!` and route to them with `.to_render()`:
+Mingling doesn't use `?` operator propagation. Instead, errors are just **alternative results** that flow through the same chain/render pipeline. Create error types with `#[derive(Grouped)]` / `#[derive(Grouped, Wrap)]` and route to them with `.to_render()`:
 
 ```rust
-use mingling::macros::pack;
 use mingling::prelude::*;
 use std::io::Write;
 
 dispatcher!("hello", EntryHello);
-pack!(ResultName = String);
-pack!(ErrorNoNameProvided = ());
-pack!(ErrorNameTooLong = u16);
+
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
+
+#[derive(Grouped)]
+pub struct ErrorNoNameProvided;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameTooLong(u16);
 
 #[chain]
 fn handle(args: EntryHello) -> Next {
-    let Some(name) = args.inner.first().cloned() else {
-        return ErrorNoNameProvided::default().to_render();  // ← early return to error renderer
+    let Some(name) = args.0.first().cloned() else {
+        return ErrorNoNameProvided.to_render();  // ← early return to error renderer
     };
 
     if name.len() > 10 {
-        return ErrorNameTooLong::new(name.len() as u16).to_render();
+        return ErrorNameTooLong(name.len() as u16).to_render();
     }
 
-    ResultName::new(name).to_render()  // ← success path
+    ResultName(name).to_render()  // ← success path
 }
 
 #[renderer]
@@ -633,7 +641,9 @@ use std::io::Write;
 use std::time::Duration;
 
 dispatcher!("download", EntryDownload);
-pack!(ResultDownloaded = String);
+
+#[derive(Grouped, Wrap)]
+pub struct ResultDownloaded(String);
 
 #[chain]
 pub async fn handle_download(args: EntryDownload) -> Next {
@@ -643,7 +653,7 @@ pub async fn handle_download(args: EntryDownload) -> Next {
 
 async fn download_file(name: String) -> ResultDownloaded {
     tokio::time::sleep(Duration::from_secs(1)).await;
-    ResultDownloaded::new(name)
+    ResultDownloaded(name)
 }
 
 #[renderer]
@@ -670,7 +680,7 @@ use mingling::macros::gen_program;
 gen_program!();
 ```
 
-It must be placed **after** all your `dispatcher!`, `pack!`, `#[chain]`, `#[renderer]`, and `#[help]` declarations.
+It must be placed **after** all your `dispatcher!` calls, `#[derive(Grouped, Wrap)]` type definitions, and `#[chain]`, `#[renderer]`, and `#[help]` declarations.
 
 ---
 
@@ -679,7 +689,6 @@ It must be placed **after** all your `dispatcher!`, `pack!`, `#[chain]`, `#[rend
 Here's a complete, runnable program:
 
 ```rust
-use mingling::macros::pack;
 use mingling::prelude::*;
 use std::io::Write;
 
@@ -690,16 +699,17 @@ fn main() {
     program.exec_and_exit();
 }
 
-pack!(ResultGreeting = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     let greeting = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultGreeting::new(greeting).into()
+    ResultGreeting(greeting).into()
 }
 
 #[renderer]
diff --git a/README.md b/README.md
index 91aa166..20947f2 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,8 @@ Mingling abstracts the behavior of a program's lifecycle into three phases: **Di
 
 ```rust
 dispatcher!("current", EntryCurrent);
-pack!(StateNext = ());
+#[derive(Grouped, Wrap, Default)]
+pub struct StateNext(());
 
 #[chain]
 fn handle_current(_: EntryCurrent) -> StateNext {
@@ -66,22 +67,26 @@ use mingling::macros::buffer;
 use mingling::prelude::*;
 
 dispatcher!("calc", EntryCalculate);
-pack!(StateSumNumbers = Vec<i32>);
-pack!(ResultNumber = i32);
+
+#[derive(Grouped, Wrap)]
+pub struct StateSumNumbers(Vec<i32>);
+
+#[derive(Grouped, Wrap)]
+pub struct ResultNumber(i32);
 
 // Entry: parse arguments and pass state to the calculation step
 #[chain]
 fn handle_calc(args: EntryCalculate) -> StateSumNumbers {
     let numbers = args.pick(&arg![Vec<i32>]).unwrap();
-    StateSumNumbers::new(numbers)
+    StateSumNumbers(numbers)
 }
 
 // Calculate: pass the result to the rendering step
 #[chain]
 fn handle_state_sum_numbers(sum: StateSumNumbers) -> ResultNumber {
-    let numbers = sum.inner;
+    let numbers = sum.0;
     let total: i32 = numbers.iter().sum();
-    ResultNumber::new(total)
+    ResultNumber(total)
 }
 
 // Renderer: return the render result and let the framework handle output
diff --git a/docs/_zh_CN/pages/11-resource-system.md b/docs/_zh_CN/pages/11-resource-system.md
index 40d8cd9..b0fbe31 100644
--- a/docs/_zh_CN/pages/11-resource-system.md
+++ b/docs/_zh_CN/pages/11-resource-system.md
@@ -31,11 +31,12 @@ fn main() {
 @@@#[derive(Default, Clone)]
 @@@struct ResCurrentDir(String);
 @@@dispatcher!("pwd", EntryPrintWorkingDir);
-@@@pack!(ResultPath = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultPath(String);
 // 通过 &T 注入只读资源
 #[chain]
 fn handle_pwd(_args: EntryPrintWorkingDir, cwd: &ResCurrentDir) -> Next {
-    ResultPath::new(cwd.0.clone()).to_render()
+    ResultPath(cwd.0.clone()).to_render()
 }
  
 #[renderer(buffer)]
@@ -53,7 +54,8 @@ fn render_path(result: ResultPath) {
 @@@#[derive(Default, Clone)]
 @@@struct ResVisitCount(u32);
 @@@dispatcher!("visit", EntryVisit);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
 #[chain]
 fn handle_visit(_args: EntryVisit, counter: &mut ResVisitCount) -> Next {
     counter.0 += 1;
@@ -74,7 +76,8 @@ Chain 可以同时注入任意多个资源，框架按类型自动匹配：
 @@@#[derive(Default, Clone)] struct ResConfig(String);
 @@@#[derive(Default, Clone)] struct ResCounter(u32);
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
 // 同时注入只读 + 可修改
 #[chain]
 fn handle_test(_args: EntryTest, config: &ResConfig, counter: &mut ResCounter) -> Next {
diff --git a/docs/_zh_CN/pages/12-exit-code.md b/docs/_zh_CN/pages/12-exit-code.md
index 7c55b60..9270b84 100644
--- a/docs/_zh_CN/pages/12-exit-code.md
+++ b/docs/_zh_CN/pages/12-exit-code.md
@@ -3,9 +3,7 @@
     如何使用资源系统管理程序退出码
 </p>
 
-程序退出时给 shell 一个正确的退出码是 CLI 的基本素养
-
-。Mingling 提供了开箱即用的 `ExitCodeSetup`，配合 `ResExitCode` 资源，让退出码控制变得极其简单。
+程序退出时给 shell 一个正确的退出码是 CLI 的基本素养。Mingling 提供了开箱即用的 `ExitCodeSetup`，配合 `ResExitCode` 资源，让退出码控制变得极其简单。
 
 ## 启用 ExitCodeSetup
 
@@ -31,7 +29,8 @@ fn main() {
 ```rust
 @@@use mingling::res::ResExitCode;
 @@@use mingling::setup::ExitCodeSetup;
-@@@pack!(EntryCheck = Vec<String>);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct EntryCheck(Vec<String>);
 #[chain]
 fn handle_check(_args: EntryCheck, ec: &mut ResExitCode) {
     // 检查失败的时候修改退出码资源
diff --git a/docs/_zh_CN/pages/13-hook.md b/docs/_zh_CN/pages/13-hook.md
index 811957c..860bd2b 100644
--- a/docs/_zh_CN/pages/13-hook.md
+++ b/docs/_zh_CN/pages/13-hook.md
@@ -55,10 +55,11 @@ Hook 覆盖了管线的完整生命周期：
 @@@use mingling::hook::ProgramHook;
 @@@
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@
 @@@#[chain] fn handle_greet(args: EntryGreet) -> Next {
-@@@    ResultName::new(args.inner.first().cloned().unwrap_or_default()).to_render()
+@@@    ResultName(args.0.first().cloned().unwrap_or_default()).to_render()
 @@@}
 @@@#[renderer] fn render_name(r: ResultName) -> RenderResult { RenderResult::new() }
 fn main() {
diff --git a/docs/_zh_CN/pages/14-testing.md b/docs/_zh_CN/pages/14-testing.md
index 30f3fc4..13585ee 100644
--- a/docs/_zh_CN/pages/14-testing.md
+++ b/docs/_zh_CN/pages/14-testing.md
@@ -12,7 +12,8 @@ Chain 只是一个接收输入、返回输出的函数，Renderer 也只是接�
 Renderer 是最容易测试的——调用函数，断言返回结果：
 
 ```rust
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer]
 fn render_greet(result: ResultName) -> RenderResult {
     let mut r = RenderResult::new();
@@ -22,7 +23,7 @@ fn render_greet(result: ResultName) -> RenderResult {
  
 #[test]
 fn test_render_name() {
-    let result = render_name(ResultName::new("Alice".to_string()));
+    let result = render_name(ResultName("Alice".to_string()));
     assert_eq!(result.to_string().as_str(), "Hello, Alice!\n");
 }
 ```
@@ -36,27 +37,29 @@ fn test_render_name() {
 ```rust
 @@@use mingling::{assert_member_id, assert_render_result, unpack_chain_process};
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultName = String);
-@@@pack!(ErrorNoName = ());
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ErrorNoName(());
 @@@#[chain]
 @@@fn handle_hello(args: EntryHello) -> Next {
-@@@    let name = args.inner.first().cloned().unwrap_or_default();
+@@@    let name = args.0.first().cloned().unwrap_or_default();
 @@@    if name.is_empty() {
 @@@        ErrorNoName::default().to_render()
 @@@    } else {
-@@@        ResultName::new(name).to_render()
+@@@        ResultName(name).to_render()
 @@@    }
 @@@}
 #[test]
 fn test_handle_hello_with_name() {
-    let chain_process = handle_hello(EntryGreet::new(vec!["Alice".to_string()])).into();
+    let chain_process = handle_hello(EntryHello(vec!["Alice".to_string()])).into();
     // 断言这是一个渲染结果（不是继续 chain）
     assert_render_result!(chain_process);
     // 断言 member_id 是 ResultName
     assert_member_id!(chain_process, ResultName);
     // 解包出内部值
     let result_name = unpack_chain_process!(chain_process, ResultName);
-    assert_eq!(result_name.inner, "Alice");
+    assert_eq!(result_name.0, "Alice");
 }
 ```
  
@@ -78,11 +81,12 @@ fn test_handle_hello_with_name() {
 @@@use mingling::{assert_member_id, unpack_chain_process};
 @@@use mingling::macros::entry;
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_hello(args: EntryHello) -> Next {
-@@@    let name = args.inner.first().cloned().unwrap_or_default();
-@@@    ResultName::new(name).to_render()
+@@@    let name = args.0.first().cloned().unwrap_or_default();
+@@@    ResultName(name).to_render()
 @@@}
 #[test]
 fn test_with_entry_macro() {
@@ -90,7 +94,7 @@ fn test_with_entry_macro() {
     let entry = entry!("--name", "Alice");
     let chain_process = handle_hello(entry).into();
     let result_name = unpack_chain_process!(chain_process, ResultName);
-    assert_eq!(result_name.inner, "Alice");
+    assert_eq!(result_name.0, "Alice");
 }
 ```
  
@@ -103,23 +107,24 @@ fn test_with_entry_macro() {
 @@@#[derive(Default, Clone)]
 @@@struct ResPrefix(String);
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultGreeting = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultGreeting(String);
 @@@
 #[chain]
 fn handle_hello(args: EntryHello, prefix: &ResPrefix) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    ResultGreeting::new(format!("{}, {}", prefix.0, name)).to_render()
+    let name = args.0.first().cloned().unwrap_or_default();
+    ResultGreeting(format!("{}, {}", prefix.0, name)).to_render()
 }
  
 #[test]
 fn test_handle_with_resource() {
     // 资源需要在测试中手动传入
     let result = handle_hello(
-        EntryHello::new(vec!["World".to_string()]),
+        EntryHello(vec!["World".to_string()]),
         &ResPrefix("Hello".to_string()),
     );
     let greeting = unpack_chain_process!(result, ResultGreeting, ThisProgram);
-    assert_eq!(greeting.inner, "Hello, World");
+    assert_eq!(greeting.0, "Hello, World");
 }
 ```
  
diff --git a/docs/_zh_CN/pages/2-define-a-dispatcher.md b/docs/_zh_CN/pages/2-define-a-dispatcher.md
index 7ae26f1..77a1513 100644
--- a/docs/_zh_CN/pages/2-define-a-dispatcher.md
+++ b/docs/_zh_CN/pages/2-define-a-dispatcher.md
@@ -48,17 +48,15 @@ dispatcher!("remote.rm",  EntryRemoteRm);
 
 ```rust
 // 示意，dispatcher! 宏实际生成的代码
-pub struct EntryGreet {
-    pub inner: Vec<String>,
-}
+pub struct EntryGreet(pub Vec<String>);
 ```
  
-用户在命令行输入 `greet Alice Bob`，`EntryGreet.inner` 就是 `vec!["Alice", "Bob"]`。
+用户在命令行输入 `greet Alice Bob`，`EntryGreet` 包裹的 `Vec<String>`（即字段 `0`）就是 `vec!["Alice", "Bob"]`。
 
 > [!IMPORTANT]
-> Entry 的 `inner` 只包含 **匹配后剩余的参数**。
+> Entry 包裹的参数只包含 **匹配后剩余的参数**。
 >
-> 以 `remote add origin` 为例，`remote` 和 `add` 用于匹配命令路径，只有 `origin` 会进入 `EntryRemoteAdd.inner`。
+> 以 `remote add origin` 为例，`remote` 和 `add` 用于匹配命令路径，只有 `origin` 会进入 `EntryRemoteAdd`（即字段 `0`）。
 
 ## 进阶：隐式声明
 
diff --git a/docs/_zh_CN/pages/3-define-a-chain.md b/docs/_zh_CN/pages/3-define-a-chain.md
index c8d8a24..3356b74 100644
--- a/docs/_zh_CN/pages/3-define-a-chain.md
+++ b/docs/_zh_CN/pages/3-define-a-chain.md
@@ -17,14 +17,15 @@
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     // args 就是用户输入经过匹配后剩下的参数
-    let name = args.inner.first().cloned().unwrap_or_else(|| "World".to_string());
+    let name = args.0.first().cloned().unwrap_or_else(|| "World".to_string());
     // 把结果包装成 Next，告诉调度器下一步去哪
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -32,7 +33,7 @@ fn handle_greet(args: EntryGreet) -> Next {
 
 Chain 函数签名里写着它需要什么——`args: EntryGreet`
 
-然后用 `ResultName::new(name)` 返回一个新类型。
+然后用 `ResultName(name)` 返回一个新类型。
 
 这个返回的 `Next` 会展开成 `impl Into<ChainProcess<ThisProgram>>`。
 
@@ -41,17 +42,30 @@ Chain 函数签名里写着它需要什么——`args: EntryGreet`
 >
 > 可以去 [任意输出机制](pages/concepts/3-any-output) 章节了解 `ChainProcess`。
 
-## `pack!` 宏
+## 用 `#[derive]` 定义管线类型
 
-你大概猜到了，`pack!(ResultName = String)` 定义了一个管线中传递的类型：
+你大概猜到了，`#[derive(Grouped, Wrap)] pub struct ResultName(String);` 定义了一个管线中传递的类型：
 
 ```rust
-// pack!(ResultName = String) 大概生成了这样的代码
+// 实际写代码时只需一行 #[derive(Grouped, Wrap)]，它大概展开成下面这些实现：
  
-#[derive(Grouped)]
-pub struct ResultName {
-    pub inner: String,
+pub struct ResultName(String);
+ 
+impl From<String> for ResultName {
+    fn from(inner: String) -> Self {
+        ResultName(inner)
+    }
+}
+ 
+impl std::ops::Deref for ResultName {
+    type Target = String;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
 }
+ 
+// Grouped 生成 member_id() → ThisProgram::ResultName，
+// 赋予类型路由身份和 Into<ChainProcess> 转换。
 ```
  
 你可以把它理解为一个 打了标签的 `String`。
@@ -59,7 +73,7 @@ pub struct ResultName {
 调度器通过这个标签来精确路由，确保数据不会混淆 —— 比如发给 `RenderGreet` 的数据不会被误传给 `RenderError`。
 
 > [!NOTE]
-> 与简单的类型别名 (`type`) 不同，`pack!` 会生成一个全新的类型，拥有独立的 `TypeId`。
+> 与简单的类型别名 (`type`) 不同，`#[derive(Grouped, Wrap)]` 会定义一个全新的类型，拥有独立的 `TypeId`。
 
 命名上推荐这样的习惯：
 
@@ -70,25 +84,26 @@ pub struct ResultName {
 | 最终结果 | `Result` + 描述  | `ResultGreetSomeone` |
 | 错误     | `Error` + 描述   | `ErrorUserNotFound`  |
 
-详见 [命名规范](pages/other/naming_rule)，不过现在你只需要记住：**用 `pack!` 给你的数据取一个有意义的名字**。
+详见 [命名规范](pages/other/naming_rule)，不过现在你只需要记住：**用 `#[derive(Grouped)]`（可搭配 `Wrap`）给你的数据取一个有意义的名字**。
 
 ## 从 Entry 中提取参数
 
-`EntryGreet` 的 `inner` 是一个 `Vec<String>`，你可以在 Chain 里自由地处理它：
+`EntryGreet` 包裹的 `Vec<String>`（即字段 `0`）你可以在 Chain 里自由地处理它：
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     // 取第一个参数，没有就用默认值
     let name = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
  
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -103,16 +118,17 @@ fn handle_greet(args: EntryGreet) -> Next {
 dispatcher!("greet", EntryGreet);
  
 // 2. 声明管线中的数据类型
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 // 3. 处理逻辑
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner
+    let name = args.0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 fn main() {
diff --git a/docs/_zh_CN/pages/4-render-result.md b/docs/_zh_CN/pages/4-render-result.md
index e3e49f5..ad915ba 100644
--- a/docs/_zh_CN/pages/4-render-result.md
+++ b/docs/_zh_CN/pages/4-render-result.md
@@ -3,7 +3,7 @@
     使用 renderer 宏声明渲染器，将结果输出
 </p>
 
-现在，我们创建了 Dispatcher 和 Chain，也通过 `pack!` 产出了一个 Result 类型。最后一步：**把结果展示给用户**。
+现在，我们创建了 Dispatcher 和 Chain，也通过 `#[derive(Grouped, Wrap)]` 产出了一个 Result 类型。最后一步：**把结果展示给用户**。
 
 ## `#[renderer]` 宏
 
@@ -11,7 +11,8 @@
 
 ```rust
 @@@use mingling::macros::buffer;
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer(buffer)]
 fn render_name(name: ResultName) {
     r_println!("Hello, {}!", *name);
@@ -27,7 +28,8 @@ Renderer 接收 Chain 产出的结果，然后返回一个 `RenderResult`。在�
 ```rust
 use mingling::macros::buffer;
  
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer(buffer)]
 fn render_name(name: ResultName) {
     r_println!("Hello, {}!", *name);
@@ -54,17 +56,18 @@ use mingling::macros::buffer;
 // 1. 用 Dispatcher 声明命令
 dispatcher!("greet", EntryGreet);
  
-// 2. 用 pack! 声明结果数据
-pack!(ResultName = String);
+// 2. 用 #[derive(Grouped, Wrap)] 声明结果数据
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 // 3. 用 Chain 处理逻辑
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner
+    let name = args.0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 // 4. 用 Renderer 输出结果
@@ -122,10 +125,10 @@ use mingling::macros::buffer;
  
 #[renderer(buffer)]
 fn render_entry_fallback(err: EntryFallback) {
-    if err.inner.is_empty() {
+    if err.0.is_empty() {
         r_println!("Unknown command");
     } else {
-        r_println!("Command not found: \"{}\"", err.inner.join(" "));
+        r_println!("Command not found: \"{}\"", err.0.join(" "));
     }
 }
 ```
@@ -144,13 +147,13 @@ Command not found: "great"
 
 你完成了第一个完整的 Mingling 程序！来回顾一下学到的东西：
 
-| 概念     | 对应宏/函数      | 一句话                     |
-| -------- | ---------------- | -------------------------- |
-| 声明命令 | `dispatcher!`    | 告诉程序用户能输入什么     |
-| 处理逻辑 | `#[chain]`       | 收到参数后做什么           |
-| 输出结果 | `#[renderer]`    | 怎么把结果告诉用户         |
-| 类型包装 | `pack!`          | 给你的数据取个有意义的名字 |
-| 程序入口 | `gen_program!()` | 自动生成管线的接线图       |
+| 概念     | 对应宏/函数                | 一句话                     |
+| -------- | -------------------------- | -------------------------- |
+| 声明命令 | `dispatcher!`              | 告诉程序用户能输入什么     |
+| 处理逻辑 | `#[chain]`                 | 收到参数后做什么           |
+| 输出结果 | `#[renderer]`              | 怎么把结果告诉用户         |
+| 类型包装 | `#[derive(Grouped, Wrap)]` | 给你的数据取个有意义的名字 |
+| 程序入口 | `gen_program!()`           | 自动生成管线的接线图       |
 
 在真实项目中你还会用到资源注入、hook、补全、REPL 等高级功能，不过核心骨架永远不变：**Dispatcher → Chain → Renderer**。
 
diff --git a/docs/_zh_CN/pages/5-multiple-commands.md b/docs/_zh_CN/pages/5-multiple-commands.md
index e0a58e7..9d9d37e 100644
--- a/docs/_zh_CN/pages/5-multiple-commands.md
+++ b/docs/_zh_CN/pages/5-multiple-commands.md
@@ -15,19 +15,21 @@
 dispatcher!("greet", EntryGreet);
 dispatcher!("add",   EntryAdd);
  
-pack!(ResultGreeting = String);
-pack!(ResultSum = i32);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ResultSum(i32);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_else(|| "World".to_string());
-    ResultGreeting::new(name).into()
+    let name = args.0.first().cloned().unwrap_or_else(|| "World".to_string());
+    ResultGreeting(name).into()
 }
  
 #[chain]
 fn handle_add(args: EntryAdd) -> Next {
-    let sum: i32 = args.inner.iter().filter_map(|s| s.parse::<i32>().ok()).sum();
-    ResultSum::new(sum).into()
+    let sum: i32 = args.0.iter().filter_map(|s| s.parse::<i32>().ok()).sum();
+    ResultSum(sum).into()
 }
  
 #[renderer(buffer)]
@@ -70,10 +72,10 @@ dispatcher!("remote.rm",  EntryRemoteRm);
 
 ## 数据类型的独立性
 
-注意我们用了两个不同的 `pack!`：
+注意我们用了两个不同的类型：
 
-- `pack!(ResultGreeting = String)`
-- `pack!(ResultSum = i32)`
+- `#[derive(Grouped, Wrap)] pub struct ResultGreeting(String);`
+- `#[derive(Grouped, Wrap)] pub struct ResultSum(i32);`
 
 它们都是独立的类型，`gen_program!()` 会给它们分配不同的枚举变体。
 
diff --git a/docs/_zh_CN/pages/6-argument-parse-picker.md b/docs/_zh_CN/pages/6-argument-parse-picker.md
index 7944d0a..6c88423 100644
--- a/docs/_zh_CN/pages/6-argument-parse-picker.md
+++ b/docs/_zh_CN/pages/6-argument-parse-picker.md
@@ -3,7 +3,7 @@
     用 Picker 完成基本的参数解析
 </p>
 
-前面教程中我们都是手动从 `EntryGreet.inner`（`Vec<String>`）中提取参数。
+前面教程中我们都是手动从 `EntryGreet.0`（`Vec<String>`）中提取参数。
 
 ```rust
 @@@ fn main() {
@@ -27,14 +27,15 @@ features = ["picker"]
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
     let name = prev
         .pick_or(&arg![String], || "World".to_string())
         .unwrap();
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -45,13 +46,14 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) -> Next {
 let name = prev
     .pick_or(&arg![String], || "World".to_string())
     .unwrap();
-@@@ResultName::new(name).into()
+@@@ResultName(name).into()
 @@@}
 ```
  
@@ -60,7 +62,8 @@ let name = prev
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) {
 @@@let name: String =
@@ -81,14 +84,15 @@ let name = prev
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
     let name = prev
         .pick_or(&arg![name: String, 'n'], || "World".to_string())
         .unwrap();
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -99,7 +103,8 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) {
 @@@let name: String =
@@ -122,7 +127,8 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultInfo = (String, u8, u32));
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultInfo((String, u8, u32));
  
 #[chain]
 fn handle_test_entry(prev: EntryTest) -> Next {
@@ -132,7 +138,7 @@ fn handle_test_entry(prev: EntryTest) -> Next {
         .pick_or_default(&arg![id: u32, 'I'])
         .unwrap();
  
-    ResultInfo::new((name, age, id)).into()
+    ResultInfo((name, age, id)).into()
 }
 ```
  
@@ -150,8 +156,10 @@ fn handle_test_entry(prev: EntryTest) -> Next {
 @@@use mingling::macros::buffer;
 @@@use mingling::macros::route;
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
-@@@pack!(ErrorNoName = ());
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ErrorNoName(());
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
@@ -162,7 +170,7 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
         })
         .to_result()
     );
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 #[renderer(buffer)]
@@ -177,12 +185,13 @@ fn render_greet(result: ResultName) {
 
 ```rust
 // Features: ["picker", "extras"]
-@@@ pack!(ErrorFail = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFail(());
 @@@ use mingling::macros::route;
 @@@ use mingling::picker::IntoPicker;
 @@@ fn func() -> mingling::ChainProcess<ThisProgram> {
 @@@ let args: Vec<String> = vec![];
-let name = route!(args.pick_or_route(&arg![String], || ErrorFail::new(()).to_chain()).to_result());
+let name = route!(args.pick_or_route(&arg![String], || ErrorFail(()).to_chain()).to_result());
 @@@ mingling::macros::empty_result!()
 @@@ }
 ```
@@ -191,11 +200,12 @@ let name = route!(args.pick_or_route(&arg![String], || ErrorFail::new(()).to_cha
 
 ```rust
 // Features: ["picker", "extras"]
-@@@ pack!(ErrorFail = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFail(());
 @@@ use mingling::picker::IntoPicker;
 @@@ fn func() -> mingling::ChainProcess<ThisProgram> {
 @@@ let args: Vec<String> = vec![];
-let name = match args.pick_or_route(&arg![String], || ErrorFail::new(()).to_chain()).to_result() {
+let name = match args.pick_or_route(&arg![String], || ErrorFail(()).to_chain()).to_result() {
     Ok(r) => r,
     Err(e) => return e,
 };
@@ -210,7 +220,8 @@ let name = match args.pick_or_route(&arg![String], || ErrorFail::new(()).to_chai
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
@@ -225,7 +236,7 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
         })
         .unwrap();
  
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -237,7 +248,8 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
 // Features: ["picker"]
 @@@use mingling::picker::value::Flag;
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
  
 #[chain]
 fn handle_entry(prev: EntryTest) -> Next {
@@ -280,12 +292,13 @@ impl SinglePickable for Address {
     }
 }
 @@@dispatcher!("connect", EntryConnect);
-@@@pack!(ResultConnected = Address);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultConnected(Address);
  
 #[chain]
 fn handle_connect_entry(prev: EntryConnect) -> Next {
     let address: Address = prev.pick_or_default(&arg![Address]).unwrap();
-    ResultConnected::new(address).into()
+    ResultConnected(address).into()
 }
  
 #[renderer(buffer)]
@@ -333,12 +346,13 @@ impl SinglePickable for Fruits {
     }
 }
 @@@dispatcher!("eat", EntryEat);
-@@@pack!(ResultFruit = Fruits);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultFruit(Fruits);
  
 #[chain]
 fn handle_eat_entry(prev: EntryEat) -> Next {
     let fruit: Fruits = prev.pick_or_default(&arg![Fruits]).unwrap();
-    ResultFruit::new(fruit).into()
+    ResultFruit(fruit).into()
 }
  
 #[renderer(buffer)]
diff --git a/docs/_zh_CN/pages/9-error-handling.md b/docs/_zh_CN/pages/9-error-handling.md
index dce48d1..463b829 100644
--- a/docs/_zh_CN/pages/9-error-handling.md
+++ b/docs/_zh_CN/pages/9-error-handling.md
@@ -20,17 +20,19 @@
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-pack!(ResultGreeting = String);
-pack!(ErrorNameEmpty = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameEmpty(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
+    let name = args.0.first().cloned().unwrap_or_default();
  
     if name.is_empty() {
-        ErrorNameEmpty::new("name is required".to_string()).to_render()
+        ErrorNameEmpty("name is required".to_string()).to_render()
     } else {
-        ResultGreeting::new(name).to_render()
+        ResultGreeting(name).to_render()
     }
 }
 ```
@@ -40,9 +42,11 @@ fn handle_greet(args: EntryGreet) -> Next {
 ```rust
 @@@use mingling::macros::buffer;
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultGreeting = String);
-@@@pack!(ErrorNameEmpty = String);
-@@@#[chain] fn handle_greet(args: EntryGreet) -> Next { ResultGreeting::new(args.inner.first().cloned().unwrap_or_default()).to_render() }
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultGreeting(String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ErrorNameEmpty(String);
+@@@#[chain] fn handle_greet(args: EntryGreet) -> Next { ResultGreeting(args.0.first().cloned().unwrap_or_default()).to_render() }
  
 #[renderer(buffer)]
 fn render_greet(result: ResultGreeting) {
@@ -63,16 +67,18 @@ fn render_error_name_empty(err: ErrorNameEmpty) {
 @@@use mingling::macros::buffer;
 dispatcher!("greet", EntryGreet);
  
-pack!(ResultGreeting = String);
-pack!(ErrorNameEmpty = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameEmpty(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
+    let name = args.0.first().cloned().unwrap_or_default();
     if name.is_empty() {
-        ErrorNameEmpty::new("name is required".to_string()).to_render()
+        ErrorNameEmpty("name is required".to_string()).to_render()
     } else {
-        ResultGreeting::new(name).to_render()
+        ResultGreeting(name).to_render()
     }
 }
  
@@ -104,14 +110,14 @@ Hello, Alice!
 Error: name is required
 ```
  
-## 关于 `pack_err!`
+## 关于错误类型
 
-如果你启用了 `extras`，还可以用 `pack_err!` 快速声明带有自动 `name` 字段的错误类型：
+不需要额外上下文、只起“标记”作用的错误类型，可以直接用 `#[derive(Grouped, Default)]` 声明：
 
 ```rust
 // Features: ["extras"]
-pack_err!(ErrorNotFound);
-// 生成: struct ErrorNotFound { pub name: String }
+#[derive(Grouped, Default)]
+pub struct ErrorNotFound;
 ```
  
 详见 [特性列表](pages/other/features)。
diff --git a/docs/_zh_CN/pages/advanced/2-structural-renderer.md b/docs/_zh_CN/pages/advanced/2-structural-renderer.md
index f2e1717..f678e2f 100644
--- a/docs/_zh_CN/pages/advanced/2-structural-renderer.md
+++ b/docs/_zh_CN/pages/advanced/2-structural-renderer.md
@@ -21,7 +21,7 @@ features = ["structural_renderer"]
 
 ## 基本用法
 
-启用 `StructuralRendererSetup` 后，用 `pack_structural!` 替代 `pack!` 来声明支持结构化输出的类型：
+启用 `StructuralRendererSetup` 后，用 `#[derive(StructuralData)]`（搭配 `serde::Serialize`、`Grouped` 和 `Wrap`）来声明支持结构化输出的类型：
 
 ```rust
 // Features: ["structural_renderer"]
@@ -29,16 +29,18 @@ features = ["structural_renderer"]
 // serde = "1"
 @@@use mingling::macros::buffer;
 @@@use mingling::setup::StructuralRendererSetup;
+@@@use mingling::StructuralData;
 @@@dispatcher!("render", EntryRender);
  
-// pack_structural! 等价于 pack! + StructuralData
-pack_structural!(ResultInfo = (String, i32));
+// #[derive(Grouped, Wrap)] + StructuralData + serde::Serialize 等价于旧版的 pack_structural!
+#[derive(serde::Serialize, StructuralData, Grouped, Wrap)]
+pub struct ResultInfo((String, i32));
  
 #[chain]
 fn handle_render(args: EntryRender) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    let age = args.inner.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
-    ResultInfo::new((name, age)).into()
+    let name = args.0.first().cloned().unwrap_or_default();
+    let age = args.0.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+    ResultInfo((name, age)).into()
 }
  
 #[renderer(buffer)]
@@ -61,7 +63,7 @@ fn render_info(r: ResultInfo) {
 
 ## 自定义输出结构
 
-`pack_structural!` 的默认输出包含 `inner` 字段。要完全控制输出结构，可以用 `#[derive(StructuralData, Serialize, Grouped)]` 手动定义类型：
+用 `#[derive(Grouped, Wrap)]` 包装的元组结构体默认输出包含 `inner` 字段。要完全控制输出结构，可以用 `#[derive(StructuralData, Serialize, Grouped)]` 手动定义类型：
 
 ```rust
 // Features: ["structural_renderer"]
@@ -82,8 +84,8 @@ struct Info {
  
 #[chain]
 fn handle_render(args: EntryRender) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    let age = args.inner.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+    let name = args.0.first().cloned().unwrap_or_default();
+    let age = args.0.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
     Info { name, age }.to_render()
 }
  
diff --git a/docs/_zh_CN/pages/concepts/2-resource.md b/docs/_zh_CN/pages/concepts/2-resource.md
index 1052254..154fa7d 100644
--- a/docs/_zh_CN/pages/concepts/2-resource.md
+++ b/docs/_zh_CN/pages/concepts/2-resource.md
@@ -34,7 +34,8 @@
 
 ```rust
 @@@ use mingling::res::ResExitCode;
-@@@ pack!(ErrorFileNotFound = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFileNotFound(());
 #[chain]
 fn handle_error_file_not_found(
     error: ErrorFileNotFound,
diff --git a/docs/_zh_CN/pages/concepts/3-any-output.md b/docs/_zh_CN/pages/concepts/3-any-output.md
index 118e856..1a2164c 100644
--- a/docs/_zh_CN/pages/concepts/3-any-output.md
+++ b/docs/_zh_CN/pages/concepts/3-any-output.md
@@ -20,7 +20,7 @@ AnyOutput<G>
  
 这里的 `G` 就是 `gen_program!()` 生成的程序枚举（也就是你熟知的 `ThisProgram`）。
 
-每个被 `pack!` 或 `#[derive(Grouped)]` 标记的类型都被分配到这个枚举的一个变体。
+每个被 `#[derive(Grouped)]`（可搭配 `Wrap`）标记的类型都被分配到这个枚举的一个变体。
 
 ## ChainProcess：数据 + 路由
 
@@ -48,7 +48,7 @@ trait Grouped<G> {
 }
 ```
  
-当你用 `pack!(ResultName = String)` 时，宏自动为 `ResultName` 实现 `Grouped`，`member_id()` 返回枚举中对应的变体。调度器一看 `member_id`，就去找对应的 Chain 或 Renderer。
+当你用 `#[derive(Grouped, Wrap)] pub struct ResultName(String);` 时，派生宏自动为 `ResultName` 实现 `Grouped`，`member_id()` 返回枚举中对应的变体。调度器一看 `member_id`，就去找对应的 Chain 或 Renderer。
 
 `to_chain()` 和 `to_render()` 本质上是 `AnyOutput` 的快捷方法，分别构造 `ChainProcess::Ok(any, Chain)` 和 `ChainProcess::Ok(any, Renderer)`。
 
@@ -66,7 +66,7 @@ trait Grouped<G> {
 > [!TIP]
 > 日常开发中你不需要手动操作 `AnyOutput` 或 `ChainProcess`。
 >
-> `pack!`、`#[chain]`、`#[renderer]` 这些宏帮你处理了所有的包装和解包。
+> `#[derive(Grouped)]`、`#[chain]`、`#[renderer]` 这些宏帮你处理了所有的包装和解包。
 
 <p align="center" style="font-size: 0.85em; color: gray;">
     Written by @Weicao-CatilGrass
diff --git a/docs/_zh_CN/pages/concepts/4-program-collect.md b/docs/_zh_CN/pages/concepts/4-program-collect.md
index a0236f6..616f645 100644
--- a/docs/_zh_CN/pages/concepts/4-program-collect.md
+++ b/docs/_zh_CN/pages/concepts/4-program-collect.md
@@ -9,7 +9,7 @@
 
 ### 1. 生成枚举
 
-扫描当前模块中所有 `pack!`、`#[chain]`、`#[renderer]` 等宏标记的类型，为每个类型生成一个枚举变体。
+扫描当前模块中所有 `#[derive(Grouped)]`、`#[chain]`、`#[renderer]` 等宏标记的类型，为每个类型生成一个枚举变体。
 
 这个枚举就是 `AnyOutput<G>` 中 `G` 的类型 —— 调度器靠枚举变体来区分管线中传递的不同数据。
 
diff --git a/docs/_zh_CN/pages/other/features.md b/docs/_zh_CN/pages/other/features.md
index 30231ce..5fa7c86 100644
--- a/docs/_zh_CN/pages/other/features.md
+++ b/docs/_zh_CN/pages/other/features.md
@@ -80,11 +80,12 @@ features = ["build_full"]
 ```rust
 // Features: ["async"]
  
-pack!(StateFoo = ());
+#[derive(Grouped, Wrap)]
+pub struct StateFoo(());
  
 #[chain]
 async fn handle_state_foo(foo: StateFoo) -> Next {
-    StateFoo::new(()).into()
+    StateFoo(()).into()
 }
 ```
  
@@ -151,14 +152,13 @@ build_comp_scripts("myprogram").unwrap();
 
 例如，允许 `dispatcher!("greet")` 的缩写形式，自动生成 `CMDGreet` / `EntryGreet`。
 
-| 宏                                                      | 说明                                   |
-| ------------------------------------------------------- | -------------------------------------- |
-| `empty_result!()`                                       | 链中提前返回空结果的简写               |
-| `entry!(Type, ["a", "b"])`                              | 构造入口类型的测试数据                 |
-| `group!(Type)`                                          | 将外部类型注册为组成员，无需修改其定义 |
-| `pack_err!(ErrorType)` / `pack_err!(ErrorType = Inner)` | 创建带自动 `name` 字段的错误类型       |
-| `#[program_setup]`                                      | 声明程序初始化函数                     |
-| `dispatcher!("cmd.path")` **缩写形式**                  | 省略 `EntryStruct`，入口类型名自动推导 |
+| 宏                                     | 说明                                   |
+| -------------------------------------- | -------------------------------------- |
+| `empty_result!()`                      | 链中提前返回空结果的简写               |
+| `entry!(Type, ["a", "b"])`             | 构造入口类型的测试数据                 |
+| `group!(Type)`                         | 将外部类型注册为组成员，无需修改其定义 |
+| `#[program_setup]`                     | 声明程序初始化函数                     |
+| `dispatcher!("cmd.path")` **缩写形式** | 省略 `EntryStruct`，入口类型名自动推导 |
 
 <details>
 <summary> Details </summary>
@@ -168,10 +168,13 @@ build_comp_scripts("myprogram").unwrap();
 ```rust
 // Features: ["extras"]
  
-pack!(StatePrev1 = ());
-pack!(StatePrev2 = ());
+#[derive(Grouped, Wrap)]
+pub struct StatePrev1(());
+#[derive(Grouped, Wrap)]
+pub struct StatePrev2(());
  
-pack!(StateNext = ());
+#[derive(Grouped, Wrap)]
+pub struct StateNext(());
  
 #[chain]
 fn handle_state_prev2(_p: StatePrev2) {
@@ -186,7 +189,7 @@ fn handle_state_prev1(_p: StatePrev1) -> Next {
         // 当需要 Next 且不需要返回值，便可以使用它
         empty_result!()
     } else {
-        StateNext::new(()).into()
+        StateNext(()).into()
     }
 }
 ```
@@ -217,7 +220,8 @@ fn no_error_setup(program: &mut Program<ThisProgram>) {
 // Features: ["extras"]
 use mingling::macros::entry;
  
-pack!(EntryHello = Vec<String>);
+#[derive(Grouped, Wrap)]
+pub struct EntryHello(Vec<String>);
  
 fn main() {
     let result: Next = handle_hello(entry!("--name", "Bob")).into();
@@ -231,7 +235,7 @@ fn handle_hello(args: EntryHello) {}
 ### `group!`
 
 将外部类型注册为程序组成员，无需修改原始类型的定义。
-类型名会直接作为枚举变体，与 `pack!` 或 `#[derive(Grouped)]` 一致。
+类型名会直接作为枚举变体，与 `#[derive(Grouped)]` 一致。
 
 ```rust
 // Features: ["extras"]
@@ -243,26 +247,23 @@ use std::num::ParseIntError;
 group!(std::num::ParseIntError);
 ```
  
-### `pack_err!`
+### 定义错误类型
 
-创建带自动 `name: String` 字段的错误结构体，字段值自动设为结构体名的蛇形命名。
-可选择包裹一个内部类型以携带额外上下文。
+0.5.0 起 `pack_err!` 已移除，错误类型直接用 derive 声明：
+不携带额外上下文时用 `#[derive(Grouped, Default)]`（仅作标记），或
+用 `#[derive(Grouped, Wrap)]` 包裹一个内部类型以携带上下文。
 
 ```rust
 // Features: ["extras"]
 use std::path::PathBuf;
  
-// 简单形式——仅包含 name 字段：
-pack_err!(ErrorNotFound);
-// 生成：
-//   struct ErrorNotFound { pub name: String }
-//   impl Default for ErrorNotFound { ... }
+// 简单形式——只作为标记使用：
+#[derive(Grouped, Default)]
+pub struct ErrorNotFound;
  
-// 带类型的形式——包含额外的 info 字段：
-pack_err!(ErrorNotDir = PathBuf);
-// 生成：
-//   struct ErrorNotDir { pub name: String, pub info: PathBuf }
-//   impl ErrorNotDir { pub fn new(info: PathBuf) -> Self { ... } }
+// 带类型的形式——包裹一个内部类型以携带上下文：
+#[derive(Grouped, Wrap)]
+pub struct ErrorNotDir(PathBuf);
 ```
  
 </details>
diff --git a/docs/_zh_CN/pages/other/naming_rule.md b/docs/_zh_CN/pages/other/naming_rule.md
index 1bca8f6..7694f56 100644
--- a/docs/_zh_CN/pages/other/naming_rule.md
+++ b/docs/_zh_CN/pages/other/naming_rule.md
@@ -94,7 +94,7 @@ Result + 内容
 | `ResultGreetSomeone` | 问候结果     |
 | `ResultFruitList`    | 水果列表结果 |
 
-结果结构体期望被 Renderer 消费，内部结构应该为了渲染美观而设计。一般用 `#[derive(Grouped)]` 代替 `pack!()` 包装，以获得更灵活的字段控制。
+结果结构体期望被 Renderer 消费，内部结构应该为了渲染美观而设计。一般用 `#[derive(Grouped)]` 标注结构体，以获得更灵活的字段控制。
 
 ### 错误
 
@@ -146,7 +146,8 @@ Error + 描述
 | 资源（可变）   | `counter`、`cache`、`session` 等 |
 
 ```rust
-@@@ pack!(EntryRemoteAdd = Vec<String>);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct EntryRemoteAdd(Vec<String>);
 @@@ #[derive(Default, Clone)]
 @@@ struct ResDatabase {  }
 @@@ #[derive(Default, Clone)]
@@ -168,9 +169,12 @@ fn handle_remote_add(args: EntryRemoteAdd, cwd: &ResCurrentDir, db: &mut ResData
 @@@ #[derive(Default, Clone)]
 @@@ struct ResDatabase {  }
 @@@ impl ResDatabase { fn has_remote(&self, remote: &String) -> bool { true } }
-@@@ pack!(StateOperationRemotes = String);
-@@@ pack!(ResultRemoteAdded = String);
-@@@ pack!(ErrorRepositoryNotFound = String);
+@@@ #[derive(Grouped, Wrap, Default)]
+@@@ pub struct StateOperationRemotes(String);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ResultRemoteAdded(String);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorRepositoryNotFound(String);
 // 分发器
 dispatcher!("remote.add", EntryRemoteAdd);
  
@@ -183,23 +187,24 @@ fn handle_remote_add(args: EntryRemoteAdd) -> Next {
 // 状态 → 错误或结果
 #[chain]
 fn handle_state_operation_remotes(state: StateOperationRemotes, db: &ResDatabase) -> Next {
-    if db.has_remote(&state.inner) {
-        ErrorRepositoryNotFound::new(state.inner).to_render()
+    if db.has_remote(&state.0) {
+        ErrorRepositoryNotFound(state.0).to_render()
     } else {
-        ResultRemoteAdded::new(state.inner).to_render()
+        ResultRemoteAdded(state.0).to_render()
     }
 }
  
 // 结果渲染
+ 
 #[renderer(buffer)]
 fn render_remote_added(result: ResultRemoteAdded) {
-    r_println!("Remote added: {}", result.inner);
+    r_println!("Remote added: {}", result.0);
 }
  
 // 错误渲染
 #[renderer(buffer)]
 fn render_error_repository_not_found(err: ErrorRepositoryNotFound) {
-    r_println!("Error: remote '{}' not found", err.inner);
+    r_println!("Error: remote '{}' not found", err.0);
 }
 ```
  
diff --git a/docs/example-pages/examples.json b/docs/example-pages/examples.json
index 8d6eaa6..38f73cd 100644
--- a/docs/example-pages/examples.json
+++ b/docs/example-pages/examples.json
@@ -273,23 +273,6 @@
     ]
   },
   {
-    "id": "example-pack-err",
-    "name": "Pack an Error",
-    "icon": "🛑",
-    "category": "macros",
-    "desc": "Demonstrates how to use the `pack_err!` macro to define error types with automatic `name` field (snake_case at compile time) and optional `info` field. Also shows `--json` serialization when `structural_renderer` is enabled.\n",
-    "tags": [
-      "pack_err!",
-      "extras",
-      "structural_renderer",
-      "--json"
-    ],
-    "files": [
-      "src/main.rs",
-      "Cargo.toml"
-    ]
-  },
-  {
     "id": "example-panic-unwind",
     "name": "Panic Unwind",
     "icon": "💥",
diff --git a/docs/pages/11-resource-system.md b/docs/pages/11-resource-system.md
index 3a4dc36..ef0d7b8 100644
--- a/docs/pages/11-resource-system.md
+++ b/docs/pages/11-resource-system.md
@@ -31,11 +31,12 @@ In a Chain or Renderer, simply declare the resource in the parameter list:
 @@@#[derive(Default, Clone)]
 @@@struct ResCurrentDir(String);
 @@@dispatcher!("pwd", EntryPrintWorkingDir);
-@@@pack!(ResultPath = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultPath(String);
 // Inject read-only resource via &T
 #[chain]
 fn handle_pwd(_args: EntryPrintWorkingDir, cwd: &ResCurrentDir) -> Next {
-    ResultPath::new(cwd.0.clone()).to_render()
+    ResultPath(cwd.0.clone()).to_render()
 }
  
 #[renderer(buffer)]
@@ -53,7 +54,8 @@ Use `&mut T` to inject a mutable resource:
 @@@#[derive(Default, Clone)]
 @@@struct ResVisitCount(u32);
 @@@dispatcher!("visit", EntryVisit);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
 #[chain]
 fn handle_visit(_args: EntryVisit, counter: &mut ResVisitCount) -> Next {
     counter.0 += 1;
@@ -74,7 +76,8 @@ A Chain can inject any number of resources at once — the framework matches the
 @@@#[derive(Default, Clone)] struct ResConfig(String);
 @@@#[derive(Default, Clone)] struct ResCounter(u32);
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
 // Inject both read-only and mutable resources
 #[chain]
 fn handle_test(_args: EntryTest, config: &ResConfig, counter: &mut ResCounter) -> Next {
diff --git a/docs/pages/12-exit-code.md b/docs/pages/12-exit-code.md
index 6828cde..8fa320c 100644
--- a/docs/pages/12-exit-code.md
+++ b/docs/pages/12-exit-code.md
@@ -29,7 +29,8 @@ In a Chain or Renderer, inject `ResExitCode` to modify the exit code:
 ```rust
 @@@use mingling::res::ResExitCode;
 @@@use mingling::setup::ExitCodeSetup;
-@@@pack!(EntryCheck = Vec<String>);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct EntryCheck(Vec<String>);
 #[chain]
 fn handle_check(_args: EntryCheck, ec: &mut ResExitCode) {
     // Modify exit code when check fails
diff --git a/docs/pages/13-hook.md b/docs/pages/13-hook.md
index 90df379..6eefd12 100644
--- a/docs/pages/13-hook.md
+++ b/docs/pages/13-hook.md
@@ -55,10 +55,11 @@ Each hook callback receives a corresponding `Hook*Info` struct containing contex
 @@@use mingling::hook::ProgramHook;
 @@@
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@
 @@@#[chain] fn handle_greet(args: EntryGreet) -> Next {
-@@@    ResultName::new(args.inner.first().cloned().unwrap_or_default()).to_render()
+@@@    ResultName(args.0.first().cloned().unwrap_or_default()).to_render()
 @@@}
 @@@#[renderer] fn render_name(r: ResultName) -> RenderResult { RenderResult::new() }
 fn main() {
diff --git a/docs/pages/14-testing.md b/docs/pages/14-testing.md
index 9f6b6ed..f0413a7 100644
--- a/docs/pages/14-testing.md
+++ b/docs/pages/14-testing.md
@@ -12,7 +12,8 @@ A Chain is just a function that takes input and returns output; a Renderer is ju
 Renderer is the easiest to test — call the function, assert the result:
 
 ```rust
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer]
 fn render_greet(result: ResultName) -> RenderResult {
     let mut r = RenderResult::new();
@@ -22,7 +23,7 @@ fn render_greet(result: ResultName) -> RenderResult {
  
 #[test]
 fn test_render_name() {
-    let result = render_name(ResultName::new("Alice".to_string()));
+    let result = render_name(ResultName("Alice".to_string()));
     assert_eq!(result.to_string().as_str(), "Hello, Alice!\n");
 }
 ```
@@ -36,27 +37,29 @@ Testing a Chain is slightly more complex because its return value is `Next` (act
 ```rust
 @@@use mingling::{assert_member_id, assert_render_result, unpack_chain_process};
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultName = String);
-@@@pack!(ErrorNoName = ());
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ErrorNoName(());
 @@@#[chain]
 @@@fn handle_hello(args: EntryHello) -> Next {
-@@@    let name = args.inner.first().cloned().unwrap_or_default();
+@@@    let name = args.0.first().cloned().unwrap_or_default();
 @@@    if name.is_empty() {
 @@@        ErrorNoName::default().to_render()
 @@@    } else {
-@@@        ResultName::new(name).to_render()
+@@@        ResultName(name).to_render()
 @@@    }
 @@@}
 #[test]
 fn test_handle_hello_with_name() {
-    let chain_process = handle_hello(EntryGreet::new(vec!["Alice".to_string()])).into();
+    let chain_process = handle_hello(EntryGreet(vec!["Alice".to_string()])).into();
     // Asserts this is a render result (not continuing the chain)
     assert_render_result!(chain_process);
     // Asserts member_id is ResultName
     assert_member_id!(chain_process, ResultName);
     // Unpacks the inner value
     let result_name = unpack_chain_process!(chain_process, ResultName);
-    assert_eq!(result_name.inner, "Alice");
+    assert_eq!(result_name.0, "Alice");
 }
 ```
  
@@ -78,11 +81,12 @@ If `extras` is enabled, you can use `entry!` to quickly construct an Entry:
 @@@use mingling::{assert_member_id, unpack_chain_process};
 @@@use mingling::macros::entry;
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_hello(args: EntryHello) -> Next {
-@@@    let name = args.inner.first().cloned().unwrap_or_default();
-@@@    ResultName::new(name).to_render()
+@@@    let name = args.0.first().cloned().unwrap_or_default();
+@@@    ResultName(name).to_render()
 @@@}
 #[test]
 fn test_with_entry_macro() {
@@ -90,7 +94,7 @@ fn test_with_entry_macro() {
     let entry = entry!("--name", "Alice");
     let chain_process = handle_hello(entry).into();
     let result_name = unpack_chain_process!(chain_process, ResultName);
-    assert_eq!(result_name.inner, "Alice");
+    assert_eq!(result_name.0, "Alice");
 }
 ```
  
@@ -103,23 +107,24 @@ If a Chain uses resources, you need to provide resource instances in the test:
 @@@#[derive(Default, Clone)]
 @@@struct ResPrefix(String);
 @@@dispatcher!("hello", EntryHello);
-@@@pack!(ResultGreeting = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultGreeting(String);
 @@@
 #[chain]
 fn handle_hello(args: EntryHello, prefix: &ResPrefix) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    ResultGreeting::new(format!("{}, {}", prefix.0, name)).to_render()
+    let name = args.0.first().cloned().unwrap_or_default();
+    ResultGreeting(format!("{}, {}", prefix.0, name)).to_render()
 }
  
 #[test]
 fn test_handle_with_resource() {
     // Resources need to be passed manually in tests
     let result = handle_hello(
-        EntryHello::new(vec!["World".to_string()]),
+        EntryHello(vec!["World".to_string()]),
         &ResPrefix("Hello".to_string()),
     );
     let greeting = unpack_chain_process!(result, ResultGreeting, ThisProgram);
-    assert_eq!(greeting.inner, "Hello, World");
+    assert_eq!(greeting.0, "Hello, World");
 }
 ```
  
diff --git a/docs/pages/2-define-a-dispatcher.md b/docs/pages/2-define-a-dispatcher.md
index efd744d..5aafb19 100644
--- a/docs/pages/2-define-a-dispatcher.md
+++ b/docs/pages/2-define-a-dispatcher.md
@@ -48,17 +48,15 @@ You might be curious about what's inside `EntryGreet`. It's essentially a struct
 
 ```rust
 // Illustration of code generated by the dispatcher! macro
-pub struct EntryGreet {
-    pub inner: Vec<String>,
-}
+pub struct EntryGreet(pub Vec<String>);
 ```
  
-When the user types `greet Alice Bob` on the command line, `EntryGreet.inner` becomes `vec!["Alice", "Bob"]`.
+When the user types `greet Alice Bob` on the command line, `EntryGreet`'s `.0` becomes `vec!["Alice", "Bob"]`.
 
 > [!IMPORTANT]
-> Entry's `inner` only contains **the remaining args after matching**.
+> Entry's `.0` only contains **the remaining args after matching**.
 >
-> Take `remote add origin` as an example: `remote` and `add` are used for matching the command path, only `origin` goes into `EntryRemoteAdd.inner`.
+> Take `remote add origin` as an example: `remote` and `add` are used for matching the command path, only `origin` goes into `EntryRemoteAdd.0`.
 
 ## Advanced: Implicit Declaration
 
diff --git a/docs/pages/3-define-a-chain.md b/docs/pages/3-define-a-chain.md
index 72ade94..ea39f6b 100644
--- a/docs/pages/3-define-a-chain.md
+++ b/docs/pages/3-define-a-chain.md
@@ -17,14 +17,15 @@ We need a Chain to process it.
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     // args contains the remaining params after matching user input
-    let name = args.inner.first().cloned().unwrap_or_else(|| "World".to_string());
+    let name = args.0.first().cloned().unwrap_or_else(|| "World".to_string());
     // Wrap the result into Next, telling the dispatcher where to go next
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -32,7 +33,7 @@ Notice anything?
 
 The Chain function signature declares what it needs — `args: EntryGreet`.
 
-Then it returns a newtype via `ResultName::new(name)`.
+Then it returns a newtype via `ResultName(name)`.
 
 This returned `Next` expands into `impl Into<ChainProcess<ThisProgram>>`.
 
@@ -41,17 +42,30 @@ This returned `Next` expands into `impl Into<ChainProcess<ThisProgram>>`.
 >
 > Check out the [Any Output Mechanism](pages/concepts/3-any-output) chapter to learn about `ChainProcess`.
 
-## The `pack!` Macro
+## Declaring Types with `#[derive(Grouped, Wrap)]`
 
-You've probably guessed it — `pack!(ResultName = String)` defines a type that flows through the pipeline:
+You've probably guessed it — `#[derive(Grouped, Wrap)] pub struct ResultName(String);` defines a type that flows through the pipeline:
 
 ```rust
-// pack!(ResultName = String) generates code roughly like this
+// #[derive(Grouped, Wrap)] generates code roughly like this
  
-#[derive(Grouped)]
-pub struct ResultName {
-    pub inner: String,
+pub struct ResultName(String);
+ 
+impl From<String> for ResultName {
+    fn from(inner: String) -> Self {
+        ResultName(inner)
+    }
+}
+ 
+impl std::ops::Deref for ResultName {
+    type Target = String;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
 }
+ 
+// Grouped generates member_id() → ThisProgram::ResultName,
+// giving the type its routing identity and Into<ChainProcess> conversion.
 ```
  
 Think of it as a **tagged** `String`.
@@ -59,7 +73,7 @@ Think of it as a **tagged** `String`.
 The dispatcher uses this tag for precise routing, ensuring data doesn't get mixed up — e.g., data sent to `RenderGreet` won't be misdelivered to `RenderError`.
 
 > [!NOTE]
-> Unlike a simple type alias (`type`), `pack!` generates a completely new type with its own `TypeId`.
+> Unlike a simple type alias (`type`), `#[derive(Grouped, Wrap)]` declares a completely new type with its own `TypeId`.
 
 Here's a recommended naming convention:
 
@@ -70,25 +84,26 @@ Here's a recommended naming convention:
 | Result       | `Result` + description | `ResultGreetSomeone` |
 | Error        | `Error` + description  | `ErrorUserNotFound`  |
 
-See [Naming Convention](pages/other/naming_rule) for details, but for now just remember: **use `pack!` to give your data a meaningful name**.
+See [Naming Convention](pages/other/naming_rule) for details, but for now just remember: **use `#[derive(Grouped)]` (optionally with `Wrap`) to give your data a meaningful name**.
 
 ## Extracting Params from Entry
 
-`EntryGreet`'s `inner` is a `Vec<String>`, which you can freely process inside a Chain:
+`EntryGreet`'s `.0` is a `Vec<String>`, which you can freely process inside a Chain:
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     // Take the first param, or use a default
     let name = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
  
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -103,16 +118,17 @@ Now let's connect the Dispatcher and Chain:
 dispatcher!("greet", EntryGreet);
  
 // 2. Declare the pipeline data type
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 // 3. Processing logic
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner
+    let name = args.0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 fn main() {
diff --git a/docs/pages/4-render-result.md b/docs/pages/4-render-result.md
index fdf8b12..70ffc96 100644
--- a/docs/pages/4-render-result.md
+++ b/docs/pages/4-render-result.md
@@ -3,7 +3,7 @@
     Declare a renderer using the <code>#[renderer]</code> macro to output results.
 </p>
 
-Now we've created a Dispatcher and a Chain, and produced a Result type via `pack!`. The final step: **present the result to the user**.
+Now we've created a Dispatcher and a Chain, and produced a Result type via `#[derive(Grouped, Wrap)]`. The final step: **present the result to the user**.
 
 ## The `#[renderer]` Macro
 
@@ -11,7 +11,8 @@ Similar to `#[chain]`, `#[renderer]` marks a function that produces output:
 
 ```rust
 @@@use mingling::macros::buffer;
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer(buffer)]
 fn render_name(name: ResultName) {
     r_println!("Hello, {}!", *name);
@@ -27,7 +28,8 @@ If you find explicitly creating and returning a `RenderResult` too verbose, you
 ```rust
 use mingling::macros::buffer;
  
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 #[renderer(buffer)]
 fn render_name(name: ResultName) {
     r_println!("Hello, {}!", *name);
@@ -54,17 +56,18 @@ use mingling::macros::buffer;
 // 1. Declare commands with a Dispatcher
 dispatcher!("greet", EntryGreet);
  
-// 2. Declare result data with pack!
-pack!(ResultName = String);
+// 2. Declare result data with #[derive(Grouped, Wrap)]
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
  
 // 3. Handle logic with a Chain
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner
+    let name = args.0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 // 4. Output results with a Renderer
@@ -122,10 +125,10 @@ use mingling::macros::buffer;
  
 #[renderer(buffer)]
 fn render_entry_fallback(err: EntryFallback) {
-    if err.inner.is_empty() {
+    if err.0.is_empty() {
         r_println!("Unknown command");
     } else {
-        r_println!("Command not found: \"{}\"", err.inner.join(" "));
+        r_println!("Command not found: \"{}\"", err.0.join(" "));
     }
 }
 ```
@@ -144,13 +147,13 @@ Command not found: "great"
 
 You've completed your first full Mingling program! Let's recap what you've learned:
 
-| Concept        | Macro / Function | One-liner                               |
-| -------------- | ---------------- | --------------------------------------- |
-| Declare cmds   | `dispatcher!`    | Tell the program what the user can type |
-| Handle logic   | `#[chain]`       | What to do when args are received       |
-| Output results | `#[renderer]`    | How to present results to the user      |
-| Type wrapping  | `pack!`          | Give your data a meaningful name        |
-| Program entry  | `gen_program!()` | Auto-generate the pipeline wiring       |
+| Concept        | Macro / Function           | One-liner                               |
+| -------------- | -------------------------- | --------------------------------------- |
+| Declare cmds   | `dispatcher!`              | Tell the program what the user can type |
+| Handle logic   | `#[chain]`                 | What to do when args are received       |
+| Output results | `#[renderer]`              | How to present results to the user      |
+| Type wrapping  | `#[derive(Grouped, Wrap)]` | Give your data a meaningful name        |
+| Program entry  | `gen_program!()`           | Auto-generate the pipeline wiring       |
 
 In real projects you'll also use advanced features like resource injection, hooks, completions, REPL, etc., but the core skeleton stays the same: **Dispatcher → Chain → Renderer**.
 
diff --git a/docs/pages/5-multiple-commands.md b/docs/pages/5-multiple-commands.md
index a5c09b0..9979cd1 100644
--- a/docs/pages/5-multiple-commands.md
+++ b/docs/pages/5-multiple-commands.md
@@ -15,19 +15,21 @@ Work in the same project:
 dispatcher!("greet", EntryGreet);
 dispatcher!("add",   EntryAdd);
  
-pack!(ResultGreeting = String);
-pack!(ResultSum = i32);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ResultSum(i32);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_else(|| "World".to_string());
-    ResultGreeting::new(name).into()
+    let name = args.0.first().cloned().unwrap_or_else(|| "World".to_string());
+    ResultGreeting(name).into()
 }
  
 #[chain]
 fn handle_add(args: EntryAdd) -> Next {
-    let sum: i32 = args.inner.iter().filter_map(|s| s.parse::<i32>().ok()).sum();
-    ResultSum::new(sum).into()
+    let sum: i32 = args.0.iter().filter_map(|s| s.parse::<i32>().ok()).sum();
+    ResultSum(sum).into()
 }
  
 #[renderer(buffer)]
@@ -70,10 +72,10 @@ Each subcommand's Entry, Chain, and Renderer are completely independent and don'
 
 ## Type Independence
 
-Notice we used two different `pack!` macros:
+Notice we used two different `#[derive(Grouped, Wrap)]` structs:
 
-- `pack!(ResultGreeting = String)`
-- `pack!(ResultSum = i32)`
+- `#[derive(Grouped, Wrap)] pub struct ResultGreeting(String);`
+- `#[derive(Grouped, Wrap)] pub struct ResultSum(i32);`
 
 They are independent types, and `gen_program!()` assigns them different enum variants.
 
diff --git a/docs/pages/6-argument-parse-picker.md b/docs/pages/6-argument-parse-picker.md
index da0fff1..9fe74eb 100644
--- a/docs/pages/6-argument-parse-picker.md
+++ b/docs/pages/6-argument-parse-picker.md
@@ -3,7 +3,7 @@
     Use Picker to perform basic argument parsing
 </p>
 
-In previous tutorials, we manually extracted parameters from `EntryGreet.inner` (`Vec<String>`).
+In previous tutorials, we manually extracted parameters from `EntryGreet.0` (`Vec<String>`).
 
 ```rust
 @@@ fn main() {
@@ -27,14 +27,15 @@ Now let's see how `Picker` is written:
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
     let name = prev
         .pick_or(&arg![String], || "World".to_string())
         .unwrap();
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -45,13 +46,14 @@ For the code above:
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) -> Next {
 let name = prev
     .pick_or(&arg![String], || "World".to_string())
     .unwrap();
-@@@ResultName::new(name).into()
+@@@ResultName(name).into()
 @@@}
 ```
  
@@ -60,7 +62,8 @@ Its semantics are:
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) {
 @@@let name: String =
@@ -81,14 +84,15 @@ If your program needs to parse flag arguments (e.g. `greet --name Alice`), decla
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
     let name = prev
         .pick_or(&arg![name: String, 'n'], || "World".to_string())
         .unwrap();
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -99,7 +103,8 @@ Its semantics:
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
 @@@#[chain]
 @@@fn handle_greet_entry(prev: EntryGreet) {
 @@@let name: String =
@@ -122,7 +127,8 @@ For a single pick, `.unwrap()` returns the value directly; for multiple picks, i
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultInfo = (String, u8, u32));
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultInfo((String, u8, u32));
  
 #[chain]
 fn handle_test_entry(prev: EntryTest) -> Next {
@@ -132,7 +138,7 @@ fn handle_test_entry(prev: EntryTest) -> Next {
         .pick_or_default(&arg![id: u32, 'I'])
         .unwrap();
  
-    ResultInfo::new((name, age, id)).into()
+    ResultInfo((name, age, id)).into()
 }
 ```
  
@@ -150,8 +156,10 @@ Here's a simple example:
 @@@use mingling::macros::buffer;
 @@@use mingling::macros::route;
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
-@@@pack!(ErrorNoName = ());
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ErrorNoName(());
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
@@ -162,7 +170,7 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
         })
         .to_result()
     );
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
  
 #[renderer(buffer)]
@@ -177,12 +185,13 @@ However, **Mingling**'s `extras` feature provides the `route!` macro for simplif
 
 ```rust
 // Features: ["picker", "extras"]
-@@@ pack!(ErrorFail = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFail(());
 @@@ use mingling::macros::route;
 @@@ use mingling::picker::IntoPicker;
 @@@ fn func() -> mingling::ChainProcess<ThisProgram> {
 @@@ let args: Vec<String> = vec![];
-let name = route!(args.pick_or_route(&arg![String], || ErrorFail::new(()).to_chain()).to_result());
+let name = route!(args.pick_or_route(&arg![String], || ErrorFail(()).to_chain()).to_result());
 @@@ mingling::macros::empty_result!()
 @@@ }
 ```
@@ -191,11 +200,12 @@ It expands to:
 
 ```rust
 // Features: ["picker", "extras"]
-@@@ pack!(ErrorFail = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFail(());
 @@@ use mingling::picker::IntoPicker;
 @@@ fn func() -> mingling::ChainProcess<ThisProgram> {
 @@@ let args: Vec<String> = vec![];
-let name = match args.pick_or_route(&arg![String], || ErrorFail::new(()).to_chain()).to_result() {
+let name = match args.pick_or_route(&arg![String], || ErrorFail(()).to_chain()).to_result() {
     Ok(r) => r,
     Err(e) => return e,
 };
@@ -210,7 +220,8 @@ After picking user input with `pick`, you can use `post` to process it immediate
 ```rust
 // Features: ["picker"]
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultName = String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultName(String);
  
 #[chain]
 fn handle_greet_entry(prev: EntryGreet) -> Next {
@@ -225,7 +236,7 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
         })
         .unwrap();
  
-    ResultName::new(name).into()
+    ResultName(name).into()
 }
 ```
  
@@ -237,7 +248,8 @@ fn handle_greet_entry(prev: EntryGreet) -> Next {
 // Features: ["picker"]
 @@@use mingling::picker::value::Flag;
 @@@dispatcher!("test", EntryTest);
-@@@pack!(ResultDone = ());
+@@@#[derive(Grouped, Wrap, Default)]
+@@@pub struct ResultDone(());
  
 #[chain]
 fn handle_entry(prev: EntryTest) -> Next {
@@ -280,12 +292,13 @@ impl SinglePickable for Address {
     }
 }
 @@@dispatcher!("connect", EntryConnect);
-@@@pack!(ResultConnected = Address);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultConnected(Address);
  
 #[chain]
 fn handle_connect_entry(prev: EntryConnect) -> Next {
     let address: Address = prev.pick_or_default(&arg![Address]).unwrap();
-    ResultConnected::new(address).into()
+    ResultConnected(address).into()
 }
  
 #[renderer(buffer)]
@@ -333,12 +346,13 @@ impl SinglePickable for Fruits {
     }
 }
 @@@dispatcher!("eat", EntryEat);
-@@@pack!(ResultFruit = Fruits);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultFruit(Fruits);
  
 #[chain]
 fn handle_eat_entry(prev: EntryEat) -> Next {
     let fruit: Fruits = prev.pick_or_default(&arg![Fruits]).unwrap();
-    ResultFruit::new(fruit).into()
+    ResultFruit(fruit).into()
 }
  
 #[renderer(buffer)]
diff --git a/docs/pages/9-error-handling.md b/docs/pages/9-error-handling.md
index eefc0f0..0cacf01 100644
--- a/docs/pages/9-error-handling.md
+++ b/docs/pages/9-error-handling.md
@@ -20,17 +20,19 @@ Error values can also take either path—you can render the error msg directly,
 
 ```rust
 @@@dispatcher!("greet", EntryGreet);
-pack!(ResultGreeting = String);
-pack!(ErrorNameEmpty = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameEmpty(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
+    let name = args.0.first().cloned().unwrap_or_default();
  
     if name.is_empty() {
-        ErrorNameEmpty::new("name is required".to_string()).to_render()
+        ErrorNameEmpty("name is required".to_string()).to_render()
     } else {
-        ResultGreeting::new(name).to_render()
+        ResultGreeting(name).to_render()
     }
 }
 ```
@@ -40,9 +42,11 @@ Then write separate Renderers:
 ```rust
 @@@use mingling::macros::buffer;
 @@@dispatcher!("greet", EntryGreet);
-@@@pack!(ResultGreeting = String);
-@@@pack!(ErrorNameEmpty = String);
-@@@#[chain] fn handle_greet(args: EntryGreet) -> Next { ResultGreeting::new(args.inner.first().cloned().unwrap_or_default()).to_render() }
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ResultGreeting(String);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct ErrorNameEmpty(String);
+@@@#[chain] fn handle_greet(args: EntryGreet) -> Next { ResultGreeting(args.0.first().cloned().unwrap_or_default()).to_render() }
  
 #[renderer(buffer)]
 fn render_greet(result: ResultGreeting) {
@@ -63,16 +67,18 @@ Each Renderer does its own job; what the user sees depends on what the Chain ret
 @@@use mingling::macros::buffer;
 dispatcher!("greet", EntryGreet);
  
-pack!(ResultGreeting = String);
-pack!(ErrorNameEmpty = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameEmpty(String);
  
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
+    let name = args.0.first().cloned().unwrap_or_default();
     if name.is_empty() {
-        ErrorNameEmpty::new("name is required".to_string()).to_render()
+        ErrorNameEmpty("name is required".to_string()).to_render()
     } else {
-        ResultGreeting::new(name).to_render()
+        ResultGreeting(name).to_render()
     }
 }
  
@@ -104,14 +110,14 @@ Hello, Alice!
 Error: name is required
 ```
  
-## About `pack_err!`
+## Declaring Error Types
 
-If you've enabled `extras`, you can use `pack_err!` to quickly declare an error type with an auto-generated `name` field:
+You can use `#[derive(Grouped, Default)]` to quickly declare an error type with no payload:
 
 ```rust
 // Features: ["extras"]
-pack_err!(ErrorNotFound);
-// Generates: struct ErrorNotFound { pub name: String }
+#[derive(Grouped, Default)]
+pub struct ErrorNotFound;
 ```
  
 See [Feature List](pages/other/features) for details.
diff --git a/docs/pages/advanced/2-structural-renderer.md b/docs/pages/advanced/2-structural-renderer.md
index e444ee6..23c7ec3 100644
--- a/docs/pages/advanced/2-structural-renderer.md
+++ b/docs/pages/advanced/2-structural-renderer.md
@@ -21,7 +21,7 @@ For more formats, enable `structural_renderer_full` (includes JSON, YAML, TOML,
 
 ## Basic Usage
 
-After enabling `StructuralRendererSetup`, use `pack_structural!` instead of `pack!` to declare types that support structured output:
+After enabling `StructuralRendererSetup`, use `#[derive(StructuralData, Grouped, Wrap)]` to declare types that support structured output:
 
 ```rust
 // Features: ["structural_renderer"]
@@ -29,16 +29,18 @@ After enabling `StructuralRendererSetup`, use `pack_structural!` instead of `pac
 // serde = "1"
 @@@use mingling::macros::buffer;
 @@@use mingling::setup::StructuralRendererSetup;
+@@@use mingling::StructuralData;
 @@@dispatcher!("render", EntryRender);
  
-// pack_structural! is equivalent to pack! + StructuralData
-pack_structural!(ResultInfo = (String, i32));
+// StructuralData + Grouped + Wrap gives the type structured output support
+#[derive(serde::Serialize, StructuralData, Grouped, Wrap)]
+pub struct ResultInfo((String, i32));
  
 #[chain]
 fn handle_render(args: EntryRender) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    let age = args.inner.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
-    ResultInfo::new((name, age)).into()
+    let name = args.0.first().cloned().unwrap_or_default();
+    let age = args.0.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+    ResultInfo((name, age)).into()
 }
  
 #[renderer(buffer)]
@@ -61,7 +63,7 @@ When the user passes `--json`, the framework automatically serializes the render
 
 ## Customizing Output Structure
 
-The default output from `pack_structural!` includes an `inner` field. For full control over the output structure, define the type manually with `#[derive(StructuralData, Serialize, Grouped)]`:
+The default output from a tuple newtype (e.g. `#[derive(StructuralData, Grouped, Wrap)]`) wraps the value under an `inner` key. For full control over the output structure, define the type manually with `#[derive(StructuralData, Serialize, Grouped)]`:
 
 ```rust
 // Features: ["structural_renderer"]
@@ -82,8 +84,8 @@ struct Info {
  
 #[chain]
 fn handle_render(args: EntryRender) -> Next {
-    let name = args.inner.first().cloned().unwrap_or_default();
-    let age = args.inner.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+    let name = args.0.first().cloned().unwrap_or_default();
+    let age = args.0.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
     Info { name, age }.to_render()
 }
  
diff --git a/docs/pages/concepts/2-resource.md b/docs/pages/concepts/2-resource.md
index ad7ee16..6f0ef99 100644
--- a/docs/pages/concepts/2-resource.md
+++ b/docs/pages/concepts/2-resource.md
@@ -34,7 +34,8 @@ For example:
 
 ```rust
 @@@ use mingling::res::ResExitCode;
-@@@ pack!(ErrorFileNotFound = ());
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorFileNotFound(());
 #[chain]
 fn handle_error_file_not_found(
     error: ErrorFileNotFound,
diff --git a/docs/pages/concepts/3-any-output.md b/docs/pages/concepts/3-any-output.md
index f02805f..2b07906 100644
--- a/docs/pages/concepts/3-any-output.md
+++ b/docs/pages/concepts/3-any-output.md
@@ -20,7 +20,7 @@ AnyOutput<G>
  
 Here `G` is the program enum generated by `gen_program!()` (i.e., `ThisProgram` as you know it).
 
-Each type annotated with `pack!` or `#[derive(Grouped)]` is assigned to one variant of this enum.
+Each type annotated with `#[derive(Grouped)]` (or `#[derive(Grouped, Wrap)]`) is assigned to one variant of this enum.
 
 ## ChainProcess: Data + Routing
 
@@ -48,7 +48,7 @@ trait Grouped<G> {
 }
 ```
  
-When you use `pack!(ResultName = String)`, the macro automatically implements `Grouped` for `ResultName`, and `member_id()` returns the corresponding enum variant. The dispatcher looks at `member_id` and finds the matching Chain or Renderer.
+When you write `#[derive(Grouped)]` on `ResultName`, the derive automatically implements `Grouped` for `ResultName`, and `member_id()` returns the corresponding enum variant. The dispatcher looks at `member_id` and finds the matching Chain or Renderer.
 
 `to_chain()` and `to_render()` are essentially convenience methods on `AnyOutput` that construct `ChainProcess::Ok(any, Chain)` and `ChainProcess::Ok(any, Renderer)` respectively.
 
@@ -66,7 +66,7 @@ This mechanism ensures **type safety**: the dispatch code generated by `gen_prog
 > [!TIP]
 > In day-to-day dev, you don't need to manually touch `AnyOutput` or `ChainProcess`.
 >
-> Macros like `pack!`, `#[chain]`, and `#[renderer]` handle all the wrapping and unwrapping for you.
+> Macros and derives like `#[derive(Grouped, Wrap)]`, `#[chain]`, and `#[renderer]` handle all the wrapping and unwrapping for you.
 
 <p align="center" style="font-size: 0.85em; color: gray;">
     Written by @Weicao-CatilGrass
diff --git a/docs/pages/concepts/4-program-collect.md b/docs/pages/concepts/4-program-collect.md
index c5203c3..bc1fbc9 100644
--- a/docs/pages/concepts/4-program-collect.md
+++ b/docs/pages/concepts/4-program-collect.md
@@ -9,7 +9,7 @@ Every Mingling program ends with a `gen_program!()` call. Behind the scenes, it
 
 ### 1. Generate an enum
 
-Scans the current module for all types marked with `pack!`, `#[chain]`, `#[renderer]` and similar macros, then generates an enum variant for each type.
+Scans the current module for all types marked with `#[derive(Grouped)]`, `#[chain]`, `#[renderer]` and similar macros, then generates an enum variant for each type.
 
 This enum is the type of `G` in `AnyOutput<G>` — the scheduler uses enum variants to distinguish different data flowing through the pipeline.
 
diff --git a/docs/pages/other/features.md b/docs/pages/other/features.md
index 3779390..b2c0ea5 100644
--- a/docs/pages/other/features.md
+++ b/docs/pages/other/features.md
@@ -80,11 +80,12 @@ Enables async runtime support, allowing `#[chain]` to bind `async` functions, e.
 ```rust
 // Features: ["async"]
  
-pack!(StateFoo = ());
+#[derive(Grouped, Wrap)]
+pub struct StateFoo(());
  
 #[chain]
 async fn handle_state_foo(foo: StateFoo) -> Next {
-    StateFoo::new(()).into()
+    StateFoo(()).into()
 }
 ```
  
@@ -151,14 +152,13 @@ Enables an additional set of macros, providing more convenient syntactic sugar a
 
 For example, allows the shorthand form `dispatcher!("greet")`, which auto-generates `CMDGreet` / `EntryGreet`.
 
-| Macro                                                   | Description                                                     |
-| ------------------------------------------------------- | --------------------------------------------------------------- |
-| `empty_result!()`                                       | Shorthand for returning an empty result early in a chain        |
-| `entry!(Type, ["a", "b"])`                              | Construct test data for an entry type                           |
-| `group!(Type)`                                          | Register external types as group members without modifying them |
-| `pack_err!(ErrorType)` / `pack_err!(ErrorType = Inner)` | Create error types with an automatic `name` field               |
-| `#[program_setup]`                                      | Declare a program initialization function                       |
-| `dispatcher!("cmd.path")` **shorthand**                 | Omit `EntryStruct`, the entry name is auto-derived              |
+| Macro                                   | Description                                                     |
+| --------------------------------------- | --------------------------------------------------------------- |
+| `empty_result!()`                       | Shorthand for returning an empty result early in a chain        |
+| `entry!(Type, ["a", "b"])`              | Construct test data for an entry type                           |
+| `group!(Type)`                          | Register external types as group members without modifying them |
+| `#[program_setup]`                      | Declare a program initialization function                       |
+| `dispatcher!("cmd.path")` **shorthand** | Omit `EntryStruct`, the entry name is auto-derived              |
 
 <details>
 <summary> Details </summary>
@@ -168,10 +168,13 @@ For example, allows the shorthand form `dispatcher!("greet")`, which auto-genera
 ```rust
 // Features: ["extras"]
  
-pack!(StatePrev1 = ());
-pack!(StatePrev2 = ());
+#[derive(Grouped, Wrap)]
+pub struct StatePrev1(());
+#[derive(Grouped, Wrap)]
+pub struct StatePrev2(());
  
-pack!(StateNext = ());
+#[derive(Grouped, Wrap)]
+pub struct StateNext(());
  
 #[chain]
 fn handle_state_prev2(_p: StatePrev2) {
@@ -186,7 +189,7 @@ fn handle_state_prev1(_p: StatePrev1) -> Next {
         // When Next is needed but no return value is required, use this
         empty_result!()
     } else {
-        StateNext::new(()).into()
+        StateNext(()).into()
     }
 }
 ```
@@ -217,7 +220,8 @@ fn no_error_setup(program: &mut Program<ThisProgram>) {
 // Features: ["extras"]
 use mingling::macros::entry;
  
-pack!(EntryHello = Vec<String>);
+#[derive(Grouped, Wrap)]
+pub struct EntryHello(Vec<String>);
  
 fn main() {
     let result: Next = handle_hello(entry!("--name", "Bob")).into();
@@ -231,7 +235,7 @@ fn handle_hello(args: EntryHello) {}
 ### `group!`
 
 Registers an external type as a member of the program group without modifying its definition.
-The type's simple name is used as the enum variant, just like `pack!` or `#[derive(Grouped)]`.
+The type's simple name is used as the enum variant, just like `#[derive(Grouped)]`.
 
 ```rust
 // Features: ["extras"]
@@ -243,26 +247,23 @@ use std::num::ParseIntError;
 group!(std::num::ParseIntError);
 ```
  
-### `pack_err!`
+### Declaring Error Types
 
-Creates an error struct with an automatic `name: String` field set to the snake_case
-of the struct name. Optionally wraps an inner type for additional context.
+Error types are declared with derives — the old `pack_err!` macro was removed in 0.5.0.
+Use `#[derive(Grouped, Default)]` for a unit error (no payload), or
+`#[derive(Grouped, Wrap)]` to wrap an inner type for additional context.
 
 ```rust
 // Features: ["extras"]
 use std::path::PathBuf;
  
-// Simple form — only a name field:
-pack_err!(ErrorNotFound);
-// Generates:
-//   struct ErrorNotFound { pub name: String }
-//   impl Default for ErrorNotFound { ... }
+// Unit form — no payload:
+#[derive(Grouped, Default)]
+pub struct ErrorNotFound;
  
-// Typed form — with additional info field:
-pack_err!(ErrorNotDir = PathBuf);
-// Generates:
-//   struct ErrorNotDir { pub name: String, pub info: PathBuf }
-//   impl ErrorNotDir { pub fn new(info: PathBuf) -> Self { ... } }
+// Typed form — wraps an inner type:
+#[derive(Grouped, Wrap)]
+pub struct ErrorNotDir(PathBuf);
 ```
  
 </details>
diff --git a/docs/pages/other/naming_rule.md b/docs/pages/other/naming_rule.md
index 770fd10..fb678aa 100644
--- a/docs/pages/other/naming_rule.md
+++ b/docs/pages/other/naming_rule.md
@@ -94,7 +94,7 @@ Result + Content
 | `ResultGreetSomeone` | Greeting result   |
 | `ResultFruitList`    | Fruit list result |
 
-Result structs are expected to be consumed by the Renderer, and their internal structure should be designed for rendering aesthetics. Generally use `#[derive(Grouped)]` instead of `pack!()` wrapping for more flexible field control.
+Result structs are expected to be consumed by the Renderer, and their internal structure should be designed for rendering aesthetics. Generally prefer a named-field struct with `#[derive(Grouped)]` over a single-field tuple wrapper (`#[derive(Grouped, Wrap)]`) for more flexible field control.
 
 ### Error
 
@@ -146,7 +146,8 @@ Error + Description
 | Resource (mutable)   | `counter`, `cache`, `session`, etc.     |
 
 ```rust
-@@@ pack!(EntryRemoteAdd = Vec<String>);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct EntryRemoteAdd(Vec<String>);
 @@@ #[derive(Default, Clone)]
 @@@ struct ResDatabase {  }
 @@@ #[derive(Default, Clone)]
@@ -168,9 +169,12 @@ fn handle_remote_add(args: EntryRemoteAdd, cwd: &ResCurrentDir, db: &mut ResData
 @@@ #[derive(Default, Clone)]
 @@@ struct ResDatabase {  }
 @@@ impl ResDatabase { fn has_remote(&self, remote: &String) -> bool { true } }
-@@@ pack!(StateOperationRemotes = String);
-@@@ pack!(ResultRemoteAdded = String);
-@@@ pack!(ErrorRepositoryNotFound = String);
+@@@ #[derive(Grouped, Wrap, Default)]
+@@@ pub struct StateOperationRemotes(String);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ResultRemoteAdded(String);
+@@@ #[derive(Grouped, Wrap)]
+@@@ pub struct ErrorRepositoryNotFound(String);
 // Dispatcher
 dispatcher!("remote.add", EntryRemoteAdd);
  
@@ -183,10 +187,10 @@ fn handle_remote_add(args: EntryRemoteAdd) -> Next {
 // State → Error or Result
 #[chain]
 fn handle_state_operation_remotes(state: StateOperationRemotes, db: &ResDatabase) -> Next {
-    if db.has_remote(&state.inner) {
-        ErrorRepositoryNotFound::new(state.inner).to_render()
+    if db.has_remote(&state.0) {
+        ErrorRepositoryNotFound(state.0).to_render()
     } else {
-        ResultRemoteAdded::new(state.inner).to_render()
+        ResultRemoteAdded(state.0).to_render()
     }
 }
  
@@ -194,13 +198,13 @@ fn handle_state_operation_remotes(state: StateOperationRemotes, db: &ResDatabase
  
 #[renderer(buffer)]
 fn render_remote_added(result: ResultRemoteAdded) {
-    r_println!("Remote added: {}", result.inner);
+    r_println!("Remote added: {}", result.0);
 }
  
 // Error rendering
 #[renderer(buffer)]
 fn render_error_repository_not_found(err: ErrorRepositoryNotFound) {
-    r_println!("Error: remote '{}' not found", err.inner);
+    r_println!("Error: remote '{}' not found", err.0);
 }
 ```
  
diff --git a/docs/res/changlog_examples/feat_program_res.rs b/docs/res/changlog_examples/feat_program_res.rs
index 5133000..e9cc4e2 100644
--- a/docs/res/changlog_examples/feat_program_res.rs
+++ b/docs/res/changlog_examples/feat_program_res.rs
@@ -22,11 +22,12 @@ fn main() {
 
 dispatcher!("modify", EntryModify);
 
-pack!(DisplayGlobal = ());
+#[derive(Grouped, Wrap)]
+pub struct DisplayGlobal(());
 
 #[chain]
 fn modify(prev: EntryModify) {
-    let (name, age) = Picker::<()>::new(prev.inner)
+    let (name, age) = Picker::<()>::new(prev.0)
         .pick::<String>("--name")
         .pick::<i32>("--age")
         .unpack_directly();
diff --git a/examples/example-argument-picker/src/main.rs b/examples/example-argument-picker/src/main.rs
index 99eee30..aefb86e 100644
--- a/examples/example-argument-picker/src/main.rs
+++ b/examples/example-argument-picker/src/main.rs
@@ -44,17 +44,32 @@ use mingling::setup::picker::BasicProgramSetup;
 
 dispatcher!("calc", EntryCalculate);
 
-pack_err!(ErrorNumberANotProvided);
-pack_err!(ErrorNumberBNotProvided);
-pack_err!(ErrorNumberOperatorNotProvided);
-pack_err!(ErrorDivisionByZero);
+#[derive(Grouped, Default)]
+pub struct ErrorNumberANotProvided;
 
-pack!(StateAdd = (f32, f32));
-pack!(StateSubtract = (f32, f32));
-pack!(StateMultiply = (f32, f32));
-pack!(StateDivide = (f32, f32));
+#[derive(Grouped, Default)]
+pub struct ErrorNumberBNotProvided;
 
-pack!(ResultNumber = f32);
+#[derive(Grouped, Default)]
+pub struct ErrorNumberOperatorNotProvided;
+
+#[derive(Grouped, Default)]
+pub struct ErrorDivisionByZero;
+
+#[derive(Grouped, Wrap)]
+pub struct StateAdd((f32, f32));
+
+#[derive(Grouped, Wrap)]
+pub struct StateSubtract((f32, f32));
+
+#[derive(Grouped, Wrap)]
+pub struct StateMultiply((f32, f32));
+
+#[derive(Grouped, Wrap)]
+pub struct StateDivide((f32, f32));
+
+#[derive(Grouped, Wrap)]
+pub struct ResultNumber(f32);
 
 #[derive(Grouped)]
 struct StateCalculate {
@@ -135,13 +150,13 @@ fn handle_calc(args: EntryCalculate) -> Next {
         //                 Use the arg! macro to define a positional argument of type f32
         //                 |
         //                 vvvvvvvvvv
-        args.pick_or_route(&arg![f32], || ErrorNumberANotProvided::default().to_chain())
+        args.pick_or_route(&arg![f32], || ErrorNumberANotProvided.to_chain())
             .pick_or_route(&arg![Operator], || {
-                ErrorNumberOperatorNotProvided::default().to_chain()
+                ErrorNumberOperatorNotProvided.to_chain()
             }) //                         Returns a routable type when not found or fails to parse
             //                            |
-            //                            vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
-            .pick_or_route(&arg![f32], || ErrorNumberBNotProvided::default().to_chain())
+            //                            vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
+            .pick_or_route(&arg![f32], || ErrorNumberBNotProvided.to_chain())
             // Use `to_result` to parse arguments
             //   and convert to Result<(Tuple, ...), Route> type
             .to_result()
@@ -149,7 +164,7 @@ fn handle_calc(args: EntryCalculate) -> Next {
     // --------- IMPORTANT ---------
 
     if operator == Operator::Slash && number_b == 0. {
-        return ErrorDivisionByZero::default().to_chain();
+        return ErrorDivisionByZero.to_chain();
     }
 
     StateCalculate {
@@ -163,41 +178,41 @@ fn handle_calc(args: EntryCalculate) -> Next {
 #[chain]
 fn handle_state_calculate(state: StateCalculate) -> Next {
     match (state.operator, state.number_a, state.number_b) {
-        (Operator::Plus, a, b) => StateAdd::new((a, b)).to_chain(),
-        (Operator::Dash, a, b) => StateSubtract::new((a, b)).to_chain(),
-        (Operator::Slash, a, b) => StateDivide::new((a, b)).to_chain(),
-        (Operator::Star, a, b) => StateMultiply::new((a, b)).to_chain(),
+        (Operator::Plus, a, b) => StateAdd((a, b)).to_chain(),
+        (Operator::Dash, a, b) => StateSubtract((a, b)).to_chain(),
+        (Operator::Slash, a, b) => StateDivide((a, b)).to_chain(),
+        (Operator::Star, a, b) => StateMultiply((a, b)).to_chain(),
     }
 }
 
 #[chain]
 fn handle_state_add(state_add: StateAdd) -> ResultNumber {
-    let (a, b) = state_add.inner;
-    ResultNumber::new(a + b)
+    let (a, b) = state_add.0;
+    ResultNumber(a + b)
 }
 
 #[chain]
 fn handle_state_subtract(state_subtract: StateSubtract) -> ResultNumber {
-    let (a, b) = state_subtract.inner;
-    ResultNumber::new(a - b)
+    let (a, b) = state_subtract.0;
+    ResultNumber(a - b)
 }
 
 #[chain]
 fn handle_state_multiply(state_multiply: StateMultiply) -> ResultNumber {
-    let (a, b) = state_multiply.inner;
-    ResultNumber::new(a * b)
+    let (a, b) = state_multiply.0;
+    ResultNumber(a * b)
 }
 
 #[chain]
 fn handle_state_divide(state_divide: StateDivide) -> ResultNumber {
-    let (a, b) = state_divide.inner;
-    ResultNumber::new(a / b)
+    let (a, b) = state_divide.0;
+    ResultNumber(a / b)
 }
 
 #[renderer]
 fn render_result_number(result: ResultNumber, setting: &ResNumberDisplaySetting) -> String {
     let round = setting.round;
-    let result = if round { result.round() } else { result.inner };
+    let result = if round { result.round() } else { result.0 };
     format!("Result: {}", result)
 }
 
diff --git a/examples/example-async-support/src/main.rs b/examples/example-async-support/src/main.rs
index 090602a..7e212d9 100644
--- a/examples/example-async-support/src/main.rs
+++ b/examples/example-async-support/src/main.rs
@@ -41,7 +41,8 @@ async fn main() {
 
 dispatcher!("download", EntryDownload);
 
-pack!(ResultDownloaded = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultDownloaded(String);
 
 // --------- IMPORTANT ---------
 #[chain]
@@ -65,5 +66,5 @@ gen_program!();
 
 async fn fake_download(file_name: String) -> ResultDownloaded {
     tokio::time::sleep(std::time::Duration::from_secs(1)).await;
-    ResultDownloaded::new(file_name)
+    ResultDownloaded(file_name)
 }
diff --git a/examples/example-basic/src/main.rs b/examples/example-basic/src/main.rs
index 44736ad..ce41b2d 100644
--- a/examples/example-basic/src/main.rs
+++ b/examples/example-basic/src/main.rs
@@ -17,11 +17,11 @@ use mingling::prelude::*;
 use std::io::Write;
 
 // Define the `greet` subcommand
-//            _____________________________ subcmd name, can be nested (e.g. "remote.add" "remote.rm")
-//           /        _____________________ dispatcher name
-//           |       /            _________ entry, records raw arguments
-//           |       |           /                         ^^^^^^^^^^^^^
-//           vvvvv   vvvvvvvv    vvvvvvvvvv                \_ equivalent to pack!(EntryGreet = Vec<String>)
+//            _________________ subcmd name, can be nested (e.g. "remote.add" "remote.rm")
+//           /
+//           |        _________ entry, records raw arguments
+//           |       /                         ^^^^^^^^^^^^^
+//           vvvvv   vvvvvvvvvv                \_ a newtype wrapper around Vec<String>
 dispatcher!("greet", EntryGreet);
 
 fn main() {
@@ -33,21 +33,22 @@ fn main() {
 }
 
 // Quickly wrap a type into a type recognizable by the current program
-//     ____________________ Wrapped type name
-//    /             _______ Wrapped type inner value
-//    |            /
-//    vvvvvvvvvv   vvvvvv
-pack!(ResultName = String);
+//     ___________________  Registers this type into ThisProgram
+//    /            _______  Adds DerefMut, Deref, Into, From wrappers
+//    |           /
+//    vvvvvvvvvv  vvvvv
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 // Define the `handle_greet` chain for parsing input text
 //                     ____________________ Previous type:
 //                    /                       Mingling deduces types at runtime and routes them to this function
 //                    |               _____ will be expanded to:
-//                    |              /        impl Into<mingling::ChainProcess<ThisProgram>>
+//                    |              /        ChainProcess<ThisProgram>
 #[chain] //           vvvvvvvvvv     vvvv
 fn handle_greet(args: EntryGreet) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
diff --git a/examples/example-combine-pathf-dispatch-tree/src/sub/mod.rs b/examples/example-combine-pathf-dispatch-tree/src/sub/mod.rs
index 2b7aba9..b04c683 100644
--- a/examples/example-combine-pathf-dispatch-tree/src/sub/mod.rs
+++ b/examples/example-combine-pathf-dispatch-tree/src/sub/mod.rs
@@ -4,12 +4,13 @@ use std::io::Write;
 
 dispatcher!("hello");
 
-pack!(ResultMessage = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultMessage(String);
 
 #[chain]
 pub fn handle_my(args: EntryHello) -> Next {
     let name: ResultMessage = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
diff --git a/examples/example-combine-pathf-metadata/src/sub/mod.rs b/examples/example-combine-pathf-metadata/src/sub/mod.rs
index ba56285..38efa2f 100644
--- a/examples/example-combine-pathf-metadata/src/sub/mod.rs
+++ b/examples/example-combine-pathf-metadata/src/sub/mod.rs
@@ -7,6 +7,7 @@ use std::io::Write;
 
 // Implicit dispatcher form — creates `CMDHello` / `EntryHello` in this module
 dispatcher!("hello");
+
 // Creates `CMDDescription` / `EntryDescription` in this module
 dispatcher!("desc", EntryDescription);
 
@@ -27,14 +28,17 @@ pub fn hello_desc() -> Description {
     }
 }
 
-pack!(ResultName = String);
-pack!(DescResult = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
+
+#[derive(Grouped, Wrap)]
+pub struct DescResult(String);
 
 /// Chain for `hello` — reads the name and produces a `ResultName`.
 #[chain]
 pub fn handle_hello(args: EntryHello) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
@@ -51,7 +55,7 @@ pub fn handle_desc(_args: EntryDescription) -> Next {
         None => "EntryHello has no description".to_string(),
     };
     // --------- IMPORTANT ---------
-    DescResult::new(msg).to_render()
+    DescResult(msg).to_render()
 }
 
 /// Renders the greeting message with the provided name.
diff --git a/examples/example-command-macro/src/main.rs b/examples/example-command-macro/src/main.rs
index e525098..6740518 100644
--- a/examples/example-command-macro/src/main.rs
+++ b/examples/example-command-macro/src/main.rs
@@ -22,27 +22,30 @@ fn main() {
     ThisProgram::new().exec_and_exit();
 }
 
-pack!(ResultGreeting = String);
-pack!(ResultGoodbye = ());
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
+
+#[derive(Grouped)]
+pub struct ResultGoodbye;
 
 // --------- IMPORTANT ---------
 // Auto-generates dispatcher!("hello.world", EntryHelloWorld);
 #[command]
 fn hello_world() -> ResultGreeting {
-    ResultGreeting::new("World".to_string())
+    ResultGreeting("World".to_string())
 }
 
 // Auto-generates dispatcher!("hello-world", EntryGreetSomeone);
 #[command(node = "greet-someone")]
 fn greet_someone(args: Vec<String>) -> ResultGreeting {
     let name = args.pick_or(&arg![String], || "World".to_string()).unwrap();
-    ResultGreeting::new(name)
+    ResultGreeting(name)
 }
 
 // Auto-generates dispatcher!("goodbye", EntryGoodBye);
 #[command(entry = EntryGoodBye)]
 fn goodbye() -> ResultGoodbye {
-    ResultGoodbye::default()
+    ResultGoodbye
 }
 // --------- IMPORTANT ---------
 
diff --git a/examples/example-completion/src/main.rs b/examples/example-completion/src/main.rs
index d363697..e14326f 100644
--- a/examples/example-completion/src/main.rs
+++ b/examples/example-completion/src/main.rs
@@ -101,7 +101,8 @@ fn complete_greet_entry(ctx: &ShellContext) -> Suggest {
 // --------- IMPORTANT ---------
 
 dispatcher!("greet", EntryGreet);
-pack!(ResultName = (u8, String));
+#[derive(Grouped, Wrap)]
+pub struct ResultName((u8, String));
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
@@ -116,7 +117,7 @@ fn handle_greet(args: EntryGreet) -> Next {
 /// Renders the greeting with the result name and repeat count.
 #[renderer]
 fn render_name(result: ResultName) -> RenderResult {
-    let (repeat, name) = result.inner;
+    let (repeat, name) = result.0;
     let mut render_result = RenderResult::new();
     let mut parts = Vec::with_capacity(repeat as usize);
     for _ in 0..repeat {
diff --git a/examples/example-error-handling/src/main.rs b/examples/example-error-handling/src/main.rs
index 05b451b..ec7e6c9 100644
--- a/examples/example-error-handling/src/main.rs
+++ b/examples/example-error-handling/src/main.rs
@@ -29,35 +29,41 @@ use std::io::Write;
 dispatcher!("hello", EntryHello);
 
 // Define error types
-pack!(ErrorNoNameProvided = ());
-pack!(ErrorNameTooLong = u16);
-pack!(ErrorNameNotAvailable = ());
+#[derive(Grouped)]
+pub struct ErrorNoNameProvided;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameTooLong(u16);
+
+#[derive(Grouped)]
+pub struct ErrorNameNotAvailable;
 
 // Define success type
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 // Pre-registered names
 static VEC_REGISTERED_NAMES: &[&str] = &["Alice", "Bob", "Charlie", "David", "Eve"];
 
 #[chain]
 fn handle_hello(args: EntryHello) -> Next {
-    let Some(name) = args.inner.first().cloned() else {
+    let Some(name) = args.0.first().cloned() else {
         // If no name is provided, pass ErrorNoNameProvided
-        return ErrorNoNameProvided::default().to_render();
+        return ErrorNoNameProvided.to_render();
     };
 
     if name.len() > 10 {
         // If the name is too long, pass ErrorNameTooLong
-        return ErrorNameTooLong::new(name.len() as u16).to_render();
+        return ErrorNameTooLong(name.len() as u16).to_render();
     }
 
     if VEC_REGISTERED_NAMES.contains(&name.as_str()) {
         // If the name already exists, pass ErrorNameNotAvailable
-        return ErrorNameNotAvailable::default().to_render();
+        return ErrorNameNotAvailable.to_render();
     }
 
     // If the name is valid, pass ResultName
-    ResultName::new(name).to_render()
+    ResultName(name).to_render()
 }
 
 /// Renders a successful greeting with the given name.
@@ -96,12 +102,7 @@ fn render_error_name_too_long(len: ErrorNameTooLong) -> RenderResult {
 #[renderer]
 fn render_entry_fallback(err: EntryFallback) -> RenderResult {
     let mut render_result = RenderResult::new();
-    writeln!(
-        render_result,
-        "Command not found: \"{}\"",
-        err.inner.join(" ")
-    )
-    .ok();
+    writeln!(render_result, "Command not found: \"{}\"", err.0.join(" ")).ok();
     render_result
 }
 
diff --git a/examples/example-exitcode/src/main.rs b/examples/example-exitcode/src/main.rs
index d3e035e..c7f731d 100644
--- a/examples/example-exitcode/src/main.rs
+++ b/examples/example-exitcode/src/main.rs
@@ -36,18 +36,21 @@ fn main() {
 
 dispatcher!("hello", EntryHello);
 
-pack!(ErrorNoNameProvided = ());
-pack!(ResultName = String);
+#[derive(Grouped)]
+pub struct ErrorNoNameProvided;
+
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 #[chain]
 fn handle_hello(args: EntryHello) -> Next {
-    let Some(name) = args.inner.first().cloned() else {
+    let Some(name) = args.0.first().cloned() else {
         // If no name is provided, pass ErrorNoNameProvided
-        return ErrorNoNameProvided::default().to_render();
+        return ErrorNoNameProvided.to_render();
     };
 
     // If the name is valid, pass ResultName
-    ResultName::new(name).to_render()
+    ResultName(name).to_render()
 }
 
 /// Renders a successful greeting with the given name.
diff --git a/examples/example-hook/src/main.rs b/examples/example-hook/src/main.rs
index 1807e5e..721cea0 100644
--- a/examples/example-hook/src/main.rs
+++ b/examples/example-hook/src/main.rs
@@ -53,12 +53,13 @@ fn main() {
     program.exec_and_exit();
 }
 
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
diff --git a/examples/example-lazy-resources/src/main.rs b/examples/example-lazy-resources/src/main.rs
index cc1604a..2243f14 100644
--- a/examples/example-lazy-resources/src/main.rs
+++ b/examples/example-lazy-resources/src/main.rs
@@ -52,7 +52,8 @@ fn init_res_large_data() -> ResLargeData {
 dispatcher!("show", EntryShow);
 dispatcher!("none", EntryNone);
 
-pack!(ResultShow = BTreeMap<Key, Value>);
+#[derive(Grouped, Wrap)]
+pub struct ResultShow(BTreeMap<Key, Value>);
 
 fn main() {
     let mut program = ThisProgram::new();
diff --git a/examples/example-metadata/src/main.rs b/examples/example-metadata/src/main.rs
index 94facb4..99a8aae 100644
--- a/examples/example-metadata/src/main.rs
+++ b/examples/example-metadata/src/main.rs
@@ -56,14 +56,17 @@ pub fn greet_desc() -> Description {
 }
 // --------- IMPORTANT ---------
 
-pack!(ResultName = String);
-pack!(DescResult = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
+
+#[derive(Grouped, Wrap)]
+pub struct DescResult(String);
 
 /// Chain for `greet` — reads the name and produces a `ResultName`.
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
@@ -81,7 +84,7 @@ fn handle_desc(_args: EntryDescription) -> Next {
         None => "EntryGreet has no description".to_string(),
     };
     // --------- IMPORTANT ---------
-    DescResult::new(msg).to_render()
+    DescResult(msg).to_render()
 }
 
 /// Chain for `nodoc` — asks for metadata on an entry that has none.
@@ -94,7 +97,7 @@ fn handle_nodoc(_args: EntryNoDescription) -> Next {
         None => "EntryDescription has no description".to_string(),
     };
     // --------- IMPORTANT ---------
-    DescResult::new(msg).to_render()
+    DescResult(msg).to_render()
 }
 
 /// Renders the greeting message with the provided name.
diff --git a/examples/example-outside-type/src/main.rs b/examples/example-outside-type/src/main.rs
index a04727f..8721d9a 100644
--- a/examples/example-outside-type/src/main.rs
+++ b/examples/example-outside-type/src/main.rs
@@ -43,7 +43,8 @@ group!(ErrorIo = std::io::Error);
 //                      you can use this syntax to create an alias simultaneously
 // --------- IMPORTANT ---------
 
-pack!(ParsedNumber = i32);
+#[derive(Grouped, Wrap)]
+pub struct ParsedNumber(i32);
 
 /// Parse the first argument as an `i32`
 ///
@@ -51,9 +52,9 @@ pack!(ParsedNumber = i32);
 /// On failure, routes to `render_parse_error` via the registered outside type.
 #[chain]
 fn parse_number(args: EntryParse) -> Next {
-    let input = args.inner.first().cloned().unwrap_or_default();
+    let input = args.0.first().cloned().unwrap_or_default();
     match input.parse::<i32>() {
-        Ok(num) => ParsedNumber::new(num).to_chain(),
+        Ok(num) => ParsedNumber(num).to_chain(),
         Err(e) => e.to_chain(),
     }
 }
diff --git a/examples/example-pack-err/Cargo.lock b/examples/example-pack-err/Cargo.lock
deleted file mode 100644
index bcfbb41..0000000
--- a/examples/example-pack-err/Cargo.lock
+++ /dev/null
@@ -1,235 +0,0 @@
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-# It is not intended for manual editing.
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-
-[[package]]
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- "mingling",
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diff --git a/examples/example-pack-err/Cargo.toml b/examples/example-pack-err/Cargo.toml
deleted file mode 100644
index ddab6fd..0000000
--- a/examples/example-pack-err/Cargo.toml
+++ /dev/null
@@ -1,16 +0,0 @@
-[package]
-name = "example-pack-err"
-version = "0.1.0"
-edition = "2024"
-
-[dependencies]
-serde = { version = "1.0.228", features = ["derive"] }
-
-[dependencies.mingling]
-path = "../../mingling"
-features = [
-    "structural_renderer",
-    "extras",
-]
-
-[workspace]
diff --git a/examples/example-pack-err/page.toml b/examples/example-pack-err/page.toml
deleted file mode 100644
index 7423087..0000000
--- a/examples/example-pack-err/page.toml
+++ /dev/null
@@ -1,10 +0,0 @@
-[example]
-id = "example-pack-err"
-name = "Pack an Error"
-icon = "🛑"
-category = "macros"
-desc = """
-Demonstrates how to use the `pack_err!` macro to define error types with automatic `name` field (snake_case at compile time) and optional `info` field. Also shows `--json` serialization when `structural_renderer` is enabled.
-"""
-tags = ["pack_err!", "extras", "structural_renderer", "--json"]
-files = ["src/main.rs", "Cargo.toml"]
diff --git a/examples/example-pack-err/src/main.rs b/examples/example-pack-err/src/main.rs
deleted file mode 100644
index e30e4cb..0000000
--- a/examples/example-pack-err/src/main.rs
+++ /dev/null
@@ -1,151 +0,0 @@
-//! Example `pack_err!`
-//!
-//! > This example demonstrates how to use the `pack_err!` macro to define error types
-//! > with automatic `name` field (set to snake_case at compile time) and optional `info` field.
-//! > Also demonstrates `--json` serialization when `structural_renderer` is enabled.
-//!
-//! Run:
-//! ```bash
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find Cargo.toml
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find src
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural --json
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural Cargo.toml --json
-//! cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural src --json
-//! ```
-//!
-//! Output:
-//! ```plaintext
-//! Search path not provided
-//! Not a directory: Cargo.toml
-//! Found directory: src
-//! {"name":"error_not_found"}
-//! {"name":"error_not_dir","info":"Cargo.toml"}
-//! {"inner":"src"}
-//! {"name":"error_not_found_structural"}
-//! {"name":"error_not_dir_structural","info":"Cargo.toml"}
-//! ```
-
-use mingling::prelude::*;
-use mingling::setup::StructuralRendererSetup;
-use std::io::Write;
-use std::path::PathBuf;
-
-dispatcher!("find", EntryFind);
-dispatcher!("find-structural", EntryFindStructural);
-
-// --------- IMPORTANT ---------
-// `pack_err!` is a convenient macro for defining error types.
-//
-//     Simple form:         pack_err!(ErrorNotFound);
-//     Typed form:          pack_err!(ErrorNotDir = PathBuf);
-//
-// The simple form generates a struct with `name: String` and `impl Default`.
-//   name = "error_not_found"  (automatically snake_cased at compile time)
-//
-// The typed form additionally generates `pub fn new(info)`.
-//   name = "error_not_dir"
-//
-// When `structural_renderer` is enabled, the struct also gets
-// `#[derive(serde::Serialize)]` for --json / --yaml output.
-// --------- IMPORTANT ---------
-
-// Simple form — name = "error_not_found"
-pack_err!(ErrorNotFound);
-
-// Typed form — name = "error_not_dir"
-pack_err!(ErrorNotDir = PathBuf);
-
-// Simple form — with StructuralData support for --json / --yaml
-pack_err_structural!(ErrorNotFoundStructural);
-
-// Typed form — with StructuralData support for --json / --yaml
-pack_err_structural!(ErrorNotDirStructural = PathBuf);
-
-// Success type with StructuralData support
-pack_structural!(ResultPath = PathBuf);
-
-#[chain]
-fn handle_find(args: EntryFind) -> Next {
-    let Some(path_str) = args.inner.first().cloned() else {
-        // No path provided → use the simple error form (Default)
-        return ErrorNotFound::default().to_render();
-    };
-
-    let path = PathBuf::from(&path_str);
-    if path.is_dir() {
-        // Is a directory → success
-        ResultPath::new(path).to_render()
-    } else {
-        // Not a directory (or doesn't exist) → use the typed error form
-        ErrorNotDir::new(path).to_render()
-    }
-}
-
-#[chain]
-fn handle_find_structural(args: EntryFindStructural) -> Next {
-    let Some(path_str) = args.inner.first().cloned() else {
-        // No path provided → use the simple error form (Default)
-        return ErrorNotFoundStructural::default().to_render();
-    };
-
-    let path = PathBuf::from(&path_str);
-    if path.is_dir() {
-        // Is a directory → success
-        ResultPath::new(path).to_render()
-    } else {
-        // Not a directory (or doesn't exist) → use the typed error form
-        ErrorNotDirStructural::new(path).to_render()
-    }
-}
-
-/// Renders the successful result with the found directory path.
-#[renderer]
-fn render_result_path(path: ResultPath) -> RenderResult {
-    let mut render_result = RenderResult::new();
-    writeln!(render_result, "Found directory: {}", path.display()).ok();
-    render_result
-}
-
-/// Renders the error when no search path is provided.
-#[renderer]
-fn render_error_not_found(_: ErrorNotFound) -> RenderResult {
-    let mut render_result = RenderResult::new();
-    writeln!(render_result, "Search path not provided").ok();
-    render_result
-}
-
-/// Renders the error when the given path is not a directory.
-#[renderer]
-fn render_error_not_dir(err: ErrorNotDir) -> RenderResult {
-    let mut render_result = RenderResult::new();
-    writeln!(render_result, "Not a directory: {}", err.info.display()).ok();
-    render_result
-}
-
-/// Renders the structural error when no search path is provided.
-#[renderer]
-fn render_error_not_found_structural(_: ErrorNotFoundStructural) -> RenderResult {
-    let mut render_result = RenderResult::new();
-    writeln!(render_result, "Search path not provided").ok();
-    render_result
-}
-
-/// Renders the structural error when the given path is not a directory.
-#[renderer]
-fn render_error_not_dir_structural(err: ErrorNotDirStructural) -> RenderResult {
-    let mut render_result = RenderResult::new();
-    writeln!(render_result, "Not a directory: {}", err.info.display()).ok();
-    render_result
-}
-
-gen_program!();
-
-fn main() {
-    let mut program = ThisProgram::new();
-    
-    // Add StructuralRendererSetup to support --json / --yaml flags
-    program.with_setup(StructuralRendererSetup);
-    
-    let _ = program.exec();
-}
diff --git a/examples/example-pack-err/test.toml b/examples/example-pack-err/test.toml
deleted file mode 100644
index c4509cb..0000000
--- a/examples/example-pack-err/test.toml
+++ /dev/null
@@ -1,35 +0,0 @@
-[[runs]]
-input = [ "find" ]
-
-expect.exit-code = 0
-expect.result = "Search path not provided"
-
-[[runs]]
-input = [ "find", "Cargo.toml" ]
-
-expect.exit-code = 0
-expect.result = "Not a directory: Cargo.toml"
-
-[[runs]]
-input = [ "find", "examples" ]
-
-expect.exit-code = 0
-expect.result = "Found directory: examples"
-
-[[runs]]
-input = [ "find-structural", "--json" ]
-
-expect.exit-code = 0
-expect.result = "{\"name\":\"error_not_found_structural\"}"
-
-[[runs]]
-input = [ "find-structural", "Cargo.toml", "--json" ]
-
-expect.exit-code = 0
-expect.result = "{\"name\":\"error_not_dir_structural\",\"info\":\"Cargo.toml\"}"
-
-[[runs]]
-input = [ "find-structural", "examples", "--json" ]
-
-expect.exit-code = 0
-expect.result = "{\"inner\":\"examples\"}"
diff --git a/examples/example-panic-unwind/src/main.rs b/examples/example-panic-unwind/src/main.rs
index 59adf07..f91b0f0 100644
--- a/examples/example-panic-unwind/src/main.rs
+++ b/examples/example-panic-unwind/src/main.rs
@@ -20,7 +20,9 @@ use mingling::{hook::ProgramHook, prelude::*};
 use std::io::Write;
 
 dispatcher!("panic", EntryPanic);
-pack!(NotPanic = ());
+
+#[derive(Grouped)]
+pub struct NotPanic;
 
 fn main() {
     let mut program = ThisProgram::new();
@@ -47,7 +49,7 @@ fn handle_panic(prev: EntryPanic) -> Next {
             // Panic happens here, will be caught
             panic!("{}", s)
         }
-        None => NotPanic::default().into(),
+        None => NotPanic.into(),
     }
 }
 
diff --git a/examples/example-pathfinder/src/sub/mod.rs b/examples/example-pathfinder/src/sub/mod.rs
index cf0a97a..b90c618 100644
--- a/examples/example-pathfinder/src/sub/mod.rs
+++ b/examples/example-pathfinder/src/sub/mod.rs
@@ -3,12 +3,14 @@ use mingling::prelude::*;
 use std::io::Write;
 
 dispatcher!("greet", EntryGreet);
-pack!(ResultName = String);
+
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 #[chain]
 pub fn handle_greet(args: EntryGreet) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
diff --git a/examples/example-repl-basic/src/main.rs b/examples/example-repl-basic/src/main.rs
index d0fad6d..9b81ced 100644
--- a/examples/example-repl-basic/src/main.rs
+++ b/examples/example-repl-basic/src/main.rs
@@ -70,7 +70,8 @@ fn main() {
 }
 
 // Create error route
-pack!(ErrorDirectoryNotExist = PathBuf);
+#[derive(Grouped, Wrap)]
+pub struct ErrorDirectoryNotExist(PathBuf);
 
 // Create commands: cd ls exit
 dispatcher!("cd", EntryCd);
@@ -79,16 +80,18 @@ dispatcher!("exit", EntryExit);
 dispatcher!("clear", EntryClear);
 
 // Define data needed for the cd command's execution phase
-pack!(StateChangeDirectory = String);
+#[derive(Grouped, Wrap)]
+pub struct StateChangeDirectory(String);
 
 // Define data needed for the ls command's rendering phase
-pack!(ResultList = Vec<String>);
+#[derive(Grouped, Wrap)]
+pub struct ResultList(Vec<String>);
 
 // Parse cd command arguments
 #[chain]
 fn parse_cd_args(prev: EntryCd) -> Next {
     let join = prev.pick_or_default(&arg![String]).unwrap();
-    StateChangeDirectory::new(join).into()
+    StateChangeDirectory(join).into()
 }
 
 // Execute directory change
@@ -96,12 +99,12 @@ fn parse_cd_args(prev: EntryCd) -> Next {
 fn handle_cd(prev: StateChangeDirectory, current_dir: &mut ResCurrentDir) -> Next {
     use just_fmt::fmt_path::fmt_path;
 
-    let join = prev.inner;
+    let join = prev.0;
     let new_dir = fmt_path(current_dir.dir.join(join)).unwrap_or_default();
 
     // If the path is not found, route to error handling
     if !new_dir.exists() {
-        return ErrorDirectoryNotExist::new(new_dir).to_render();
+        return ErrorDirectoryNotExist(new_dir).to_render();
     }
 
     current_dir.dir = new_dir;
@@ -126,14 +129,14 @@ fn handle_ls(_prev: EntryLs, current_dir: &ResCurrentDir) -> Next {
         .collect();
 
     // Render ResultList
-    ResultList::new(entries).to_render()
+    ResultList(entries).to_render()
 }
 
 /// Render ResultList data
 #[renderer]
 fn render_list(list: ResultList) -> RenderResult {
     let mut render_result = RenderResult::new();
-    for item in list.inner {
+    for item in list.0 {
         writeln!(render_result, "{}", item).ok();
     }
     render_result
@@ -160,12 +163,7 @@ fn handle_clear(_prev: EntryClear) {
 #[renderer]
 fn render_error_directory_not_exist(err: ErrorDirectoryNotExist) -> RenderResult {
     let mut render_result = RenderResult::new();
-    writeln!(
-        render_result,
-        "Directory not found: {}",
-        err.inner.display()
-    )
-    .ok();
+    writeln!(render_result, "Directory not found: {}", err.0.display()).ok();
     render_result
 }
 
diff --git a/examples/example-setup/src/main.rs b/examples/example-setup/src/main.rs
index 523a567..59c503f 100644
--- a/examples/example-setup/src/main.rs
+++ b/examples/example-setup/src/main.rs
@@ -55,13 +55,14 @@ fn custom_setup(program: &mut Program<ThisProgram>) {
 
 dispatcher!("greet", EntryGreet);
 
-pack!(ResultGreeting = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultGreeting(String);
 
 /// Chain: reads the `ResAppName` and `ResAppVersion` resources.
 #[chain]
 fn handle_greet(args: EntryGreet, app: &ResAppName, version: &ResAppVersion) -> Next {
     let who = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string());
diff --git a/examples/example-structural-renderer/src/main.rs b/examples/example-structural-renderer/src/main.rs
index a1bddbd..c1cfd69 100644
--- a/examples/example-structural-renderer/src/main.rs
+++ b/examples/example-structural-renderer/src/main.rs
@@ -32,7 +32,8 @@ fn main() {
 }
 
 // --------- IMPORTANT ---------
-// For beautiful output structure, do not use `pack!` to wrap the types that need to be output.
+// For beautiful output structure, do not wrap the types that need to be output
+// in a newtype; instead, use a named struct.
 // Instead, manually implement
 //        ____________________________________ Mark as structured data so it can be rendered
 //       /                ____________________ Implement serde::Serialize
@@ -48,7 +49,7 @@ struct Info {
 }
 // This will output: {"member_name":"name","member_age":32} structure
 
-// If using pack!(Info = (String, i32));
+// If wrapping with a tuple newtype (e.g. `#[derive(Grouped, Wrap)] pub struct Info((String, i32));`)
 // Output: {"inner":["name", 32]}
 
 // --------- IMPORTANT ---------
diff --git a/examples/example-unit-test/src/main.rs b/examples/example-unit-test/src/main.rs
index 29ff9da..e4c6504 100644
--- a/examples/example-unit-test/src/main.rs
+++ b/examples/example-unit-test/src/main.rs
@@ -36,30 +36,30 @@ mod tests {
         let hello_with_valid_name = handle_hello(entry!("Peter")).into();
         assert_render_result!(hello_with_valid_name);
         let result_name = unpack_chain_process!(hello_with_valid_name, ResultName);
-        assert_eq!(result_name.inner, "Peter");
+        assert_eq!(result_name.0, "Peter");
     }
 
     #[test]
     fn test_render_result_name() {
-        let r = render_result_name(ResultName::new("Peter".into()));
+        let r = render_result_name(ResultName("Peter".into()));
         assert_eq!(r.to_string().as_str(), "Hello, Peter!")
     }
 
     #[test]
     fn test_render_error_no_name_provided() {
-        let r = render_error_no_name_provided(ErrorNoNameProvided::default());
+        let r = render_error_no_name_provided(ErrorNoNameProvided);
         assert_eq!(r.to_string().as_str(), "No name provided")
     }
 
     #[test]
     fn test_render_error_name_not_available() {
-        let r = render_error_name_not_available(ErrorNameNotAvailable::default());
+        let r = render_error_name_not_available(ErrorNameNotAvailable);
         assert_eq!(r.to_string().as_str(), "Name not available")
     }
 
     #[test]
     fn test_render_error_name_too_long() {
-        let r = render_error_name_too_long(ErrorNameTooLong::new(17));
+        let r = render_error_name_too_long(ErrorNameTooLong(17));
         assert_eq!(r.to_string().as_str(), "Name too long: 17 > 10")
     }
     // --------- IMPORTANT ---------
@@ -67,29 +67,35 @@ mod tests {
 
 dispatcher!("hello", EntryHello);
 
-pack!(ErrorNoNameProvided = ());
-pack!(ErrorNameTooLong = u16);
-pack!(ErrorNameNotAvailable = ());
+#[derive(Grouped)]
+pub struct ErrorNoNameProvided;
 
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorNameTooLong(u16);
+
+#[derive(Grouped)]
+pub struct ErrorNameNotAvailable;
+
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 static VEC_REGISTERED_NAMES: &[&str] = &["Alice", "Bob", "Charlie", "David", "Eve"];
 
 #[chain]
 fn handle_hello(args: EntryHello) -> Next {
-    let Some(name) = args.inner.first().cloned() else {
-        return ErrorNoNameProvided::default().to_render();
+    let Some(name) = args.0.first().cloned() else {
+        return ErrorNoNameProvided.to_render();
     };
 
     if name.len() > 10 {
-        return ErrorNameTooLong::new(name.len() as u16).to_render();
+        return ErrorNameTooLong(name.len() as u16).to_render();
     }
 
     if VEC_REGISTERED_NAMES.contains(&name.as_str()) {
-        return ErrorNameNotAvailable::default().to_render();
+        return ErrorNameNotAvailable.to_render();
     }
 
-    ResultName::new(name).to_render()
+    ResultName(name).to_render()
 }
 
 /// Renders a successful greeting with the given name.
@@ -128,12 +134,7 @@ fn render_error_name_too_long(len: ErrorNameTooLong) -> RenderResult {
 #[renderer]
 fn render_entry_fallback(err: EntryFallback) -> RenderResult {
     let mut render_result = RenderResult::new();
-    writeln!(
-        render_result,
-        "Command not found: \"{}\"",
-        err.inner.join(" ")
-    )
-    .ok();
+    writeln!(render_result, "Command not found: \"{}\"", err.0.join(" ")).ok();
     render_result
 }
 
diff --git a/examples/full-todolist/src/main.rs b/examples/full-todolist/src/main.rs
index eea417a..9c7bfe8 100644
--- a/examples/full-todolist/src/main.rs
+++ b/examples/full-todolist/src/main.rs
@@ -36,15 +36,25 @@ dispatcher!("clean");
 
 // Define states
 
-pack!(StateAddTodo = String);
-pack!(StateCompleteTodo = i32);
-pack!(StateListTodo = bool);
+#[derive(Grouped, Wrap)]
+pub struct StateAddTodo(String);
+
+#[derive(Grouped, Wrap)]
+pub struct StateCompleteTodo(i32);
+
+#[derive(Grouped, Wrap)]
+pub struct StateListTodo(bool);
 
 // Define errors
 
-pack!(ErrorNoTaskDescriptionProvided = ());
-pack!(ErrorNoIndexProvided = ());
-pack!(ErrorIndexOutOfBounds = ());
+#[derive(Grouped)]
+pub struct ErrorNoTaskDescriptionProvided;
+
+#[derive(Grouped)]
+pub struct ErrorNoIndexProvided;
+
+#[derive(Grouped)]
+pub struct ErrorIndexOutOfBounds;
 
 fn main() {
     let mut program = ThisProgram::new();
@@ -76,11 +86,11 @@ fn main() {
 fn handle_add(args: EntryAdd) -> Next {
     let task: String = route! {
         args.pick_or_route(&arg![String], || {
-            ErrorNoTaskDescriptionProvided::new(()).to_chain()
+            ErrorNoTaskDescriptionProvided.to_chain()
         })
         .to_result()
     };
-    StateAddTodo::new(task).to_chain()
+    StateAddTodo(task).to_chain()
 }
 
 #[chain]
@@ -92,7 +102,7 @@ fn handle_state_add_todo(
     let todolist = todolist.get_mut();
 
     // Unpack state and read description
-    let description = state.inner;
+    let description = state.0;
 
     todolist.items.push(Todo {
         item: description,
@@ -117,10 +127,10 @@ fn handle_list(_args: EntryList, todolist: &mut LazyRes<ResTodoList>) -> Next {
 #[chain]
 fn handle_complete(args: EntryComplete) -> Next {
     let index: i32 = route! {
-        args.pick_or_route(&arg![i32], || ErrorNoIndexProvided::new(()).to_chain())
+        args.pick_or_route(&arg![i32], || ErrorNoIndexProvided.to_chain())
             .to_result()
     };
-    StateCompleteTodo::new(index).to_chain()
+    StateCompleteTodo(index).to_chain()
 }
 
 #[chain]
@@ -129,12 +139,12 @@ fn handle_state_complete_todo(
     todolist: &mut LazyRes<ResTodoList>,
 ) -> Next {
     let todolist = todolist.get_mut();
-    let index = state.inner as usize;
+    let index = state.0 as usize;
     if index < todolist.items.len() {
         todolist.items[index].completed = true;
         todolist.clone().to_render()
     } else {
-        ErrorIndexOutOfBounds::new(()).to_render()
+        ErrorIndexOutOfBounds.to_render()
     }
 }
 
diff --git a/mingling/src/docs/lib.md b/mingling/src/docs/lib.md
index 91858d0..3b1f328 100644
--- a/mingling/src/docs/lib.md
+++ b/mingling/src/docs/lib.md
@@ -29,12 +29,13 @@ fn main() {
     program.exec_and_exit();
 }
 
-pack!(ResultName = String);
+#[derive(Grouped, Wrap)]
+pub struct ResultName(String);
 
 #[chain]
 fn handle_greet(args: EntryGreet) -> Next {
     let name: ResultName = args
-        .inner
+        .0
         .first()
         .cloned()
         .unwrap_or_else(|| "World".to_string())
diff --git a/mingling/src/example_docs.rs b/mingling/src/example_docs.rs
index 9406ddc..d37e762 100644
--- a/mingling/src/example_docs.rs
+++ b/mingling/src/example_docs.rs
@@ -64,17 +64,32 @@
 ///
 /// dispatcher!("calc", EntryCalculate);
 ///
-/// pack_err!(ErrorNumberANotProvided);
-/// pack_err!(ErrorNumberBNotProvided);
-/// pack_err!(ErrorNumberOperatorNotProvided);
-/// pack_err!(ErrorDivisionByZero);
+/// #[derive(Grouped, Default)]
+/// pub struct ErrorNumberANotProvided;
 ///
-/// pack!(StateAdd = (f32, f32));
-/// pack!(StateSubtract = (f32, f32));
-/// pack!(StateMultiply = (f32, f32));
-/// pack!(StateDivide = (f32, f32));
+/// #[derive(Grouped, Default)]
+/// pub struct ErrorNumberBNotProvided;
 ///
-/// pack!(ResultNumber = f32);
+/// #[derive(Grouped, Default)]
+/// pub struct ErrorNumberOperatorNotProvided;
+///
+/// #[derive(Grouped, Default)]
+/// pub struct ErrorDivisionByZero;
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct StateAdd((f32, f32));
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct StateSubtract((f32, f32));
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct StateMultiply((f32, f32));
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct StateDivide((f32, f32));
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultNumber(f32);
 ///
 /// #[derive(Grouped)]
 /// struct StateCalculate {
@@ -155,13 +170,13 @@
 ///         //                 Use the arg! macro to define a positional argument of type f32
 ///         //                 |
 ///         //                 vvvvvvvvvv
-///         args.pick_or_route(&arg![f32], || ErrorNumberANotProvided::default().to_chain())
+///         args.pick_or_route(&arg![f32], || ErrorNumberANotProvided.to_chain())
 ///             .pick_or_route(&arg![Operator], || {
-///                 ErrorNumberOperatorNotProvided::default().to_chain()
+///                 ErrorNumberOperatorNotProvided.to_chain()
 ///             }) //                         Returns a routable type when not found or fails to parse
 ///             //                            |
-///             //                            vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
-///             .pick_or_route(&arg![f32], || ErrorNumberBNotProvided::default().to_chain())
+///             //                            vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
+///             .pick_or_route(&arg![f32], || ErrorNumberBNotProvided.to_chain())
 ///             // Use `to_result` to parse arguments
 ///             //   and convert to Result<(Tuple, ...), Route> type
 ///             .to_result()
@@ -169,7 +184,7 @@
 ///     // --------- IMPORTANT ---------
 ///
 ///     if operator == Operator::Slash && number_b == 0. {
-///         return ErrorDivisionByZero::default().to_chain();
+///         return ErrorDivisionByZero.to_chain();
 ///     }
 ///
 ///     StateCalculate {
@@ -183,41 +198,41 @@
 /// #[chain]
 /// fn handle_state_calculate(state: StateCalculate) -> Next {
 ///     match (state.operator, state.number_a, state.number_b) {
-///         (Operator::Plus, a, b) => StateAdd::new((a, b)).to_chain(),
-///         (Operator::Dash, a, b) => StateSubtract::new((a, b)).to_chain(),
-///         (Operator::Slash, a, b) => StateDivide::new((a, b)).to_chain(),
-///         (Operator::Star, a, b) => StateMultiply::new((a, b)).to_chain(),
+///         (Operator::Plus, a, b) => StateAdd((a, b)).to_chain(),
+///         (Operator::Dash, a, b) => StateSubtract((a, b)).to_chain(),
+///         (Operator::Slash, a, b) => StateDivide((a, b)).to_chain(),
+///         (Operator::Star, a, b) => StateMultiply((a, b)).to_chain(),
 ///     }
 /// }
 ///
 /// #[chain]
 /// fn handle_state_add(state_add: StateAdd) -> ResultNumber {
-///     let (a, b) = state_add.inner;
-///     ResultNumber::new(a + b)
+///     let (a, b) = state_add.0;
+///     ResultNumber(a + b)
 /// }
 ///
 /// #[chain]
 /// fn handle_state_subtract(state_subtract: StateSubtract) -> ResultNumber {
-///     let (a, b) = state_subtract.inner;
-///     ResultNumber::new(a - b)
+///     let (a, b) = state_subtract.0;
+///     ResultNumber(a - b)
 /// }
 ///
 /// #[chain]
 /// fn handle_state_multiply(state_multiply: StateMultiply) -> ResultNumber {
-///     let (a, b) = state_multiply.inner;
-///     ResultNumber::new(a * b)
+///     let (a, b) = state_multiply.0;
+///     ResultNumber(a * b)
 /// }
 ///
 /// #[chain]
 /// fn handle_state_divide(state_divide: StateDivide) -> ResultNumber {
-///     let (a, b) = state_divide.inner;
-///     ResultNumber::new(a / b)
+///     let (a, b) = state_divide.0;
+///     ResultNumber(a / b)
 /// }
 ///
 /// #[renderer]
 /// fn render_result_number(result: ResultNumber, setting: &ResNumberDisplaySetting) -> String {
 ///     let round = setting.round;
-///     let result = if round { result.round() } else { result.inner };
+///     let result = if round { result.round() } else { result.0 };
 ///     format!("Result: {}", result)
 /// }
 ///
@@ -310,7 +325,8 @@ pub mod example_argument_picker {}
 ///
 /// dispatcher!("download", EntryDownload);
 ///
-/// pack!(ResultDownloaded = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultDownloaded(String);
 ///
 /// // --------- IMPORTANT ---------
 /// #[chain]
@@ -334,7 +350,7 @@ pub mod example_argument_picker {}
 ///
 /// async fn fake_download(file_name: String) -> ResultDownloaded {
 ///     tokio::time::sleep(std::time::Duration::from_secs(1)).await;
-///     ResultDownloaded::new(file_name)
+///     ResultDownloaded(file_name)
 /// }
 /// ```
 pub mod example_async_support {}
@@ -372,11 +388,11 @@ pub mod example_async_support {}
 /// use std::io::Write;
 ///
 /// // Define the `greet` subcommand
-/// //            _____________________________ subcmd name, can be nested (e.g. "remote.add" "remote.rm")
-/// //           /        _____________________ dispatcher name
-/// //           |       /            _________ entry, records raw arguments
-/// //           |       |           /                         ^^^^^^^^^^^^^
-/// //           vvvvv   vvvvvvvv    vvvvvvvvvv                \_ equivalent to pack!(EntryGreet = Vec<String>)
+/// //            _________________ subcmd name, can be nested (e.g. "remote.add" "remote.rm")
+/// //           /
+/// //           |        _________ entry, records raw arguments
+/// //           |       /                         ^^^^^^^^^^^^^
+/// //           vvvvv   vvvvvvvvvv                \_ a newtype wrapper around Vec<String>
 /// dispatcher!("greet", EntryGreet);
 ///
 /// fn main() {
@@ -388,21 +404,22 @@ pub mod example_async_support {}
 /// }
 ///
 /// // Quickly wrap a type into a type recognizable by the current program
-/// //     ____________________ Wrapped type name
-/// //    /             _______ Wrapped type inner value
-/// //    |            /
-/// //    vvvvvvvvvv   vvvvvv
-/// pack!(ResultName = String);
+/// //     ___________________  Registers this type into ThisProgram
+/// //    /            _______  Adds DerefMut, Deref, Into, From wrappers
+/// //    |           /
+/// //    vvvvvvvvvv  vvvvv
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
 ///
 /// // Define the `handle_greet` chain for parsing input text
 /// //                     ____________________ Previous type:
 /// //                    /                       Mingling deduces types at runtime and routes them to this function
 /// //                    |               _____ will be expanded to:
-/// //                    |              /        impl Into<mingling::ChainProcess<ThisProgram>>
+/// //                    |              /        ChainProcess<ThisProgram>
 /// #[chain] //           vvvvvvvvvv     vvvv
 /// fn handle_greet(args: EntryGreet) -> Next {
 ///     let name: ResultName = args
-///         .inner
+///         .0
 ///         .first()
 ///         .cloned()
 ///         .unwrap_or_else(|| "World".to_string())
@@ -745,27 +762,30 @@ pub mod example_combine_pathf_metadata {}
 ///     ThisProgram::new().exec_and_exit();
 /// }
 ///
-/// pack!(ResultGreeting = String);
-/// pack!(ResultGoodbye = ());
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultGreeting(String);
+///
+/// #[derive(Grouped)]
+/// pub struct ResultGoodbye;
 ///
 /// // --------- IMPORTANT ---------
 /// // Auto-generates dispatcher!("hello.world", EntryHelloWorld);
 /// #[command]
 /// fn hello_world() -> ResultGreeting {
-///     ResultGreeting::new("World".to_string())
+///     ResultGreeting("World".to_string())
 /// }
 ///
 /// // Auto-generates dispatcher!("hello-world", EntryGreetSomeone);
 /// #[command(node = "greet-someone")]
 /// fn greet_someone(args: Vec<String>) -> ResultGreeting {
 ///     let name = args.pick_or(&arg![String], || "World".to_string()).unwrap();
-///     ResultGreeting::new(name)
+///     ResultGreeting(name)
 /// }
 ///
 /// // Auto-generates dispatcher!("goodbye", EntryGoodBye);
 /// #[command(entry = EntryGoodBye)]
 /// fn goodbye() -> ResultGoodbye {
-///     ResultGoodbye::default()
+///     ResultGoodbye
 /// }
 /// // --------- IMPORTANT ---------
 ///
@@ -918,7 +938,8 @@ pub mod example_command_macro {}
 /// // --------- IMPORTANT ---------
 ///
 /// dispatcher!("greet", EntryGreet);
-/// pack!(ResultName = (u8, String));
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName((u8, String));
 ///
 /// #[chain]
 /// fn handle_greet(args: EntryGreet) -> Next {
@@ -933,7 +954,7 @@ pub mod example_command_macro {}
 /// /// Renders the greeting with the result name and repeat count.
 /// #[renderer]
 /// fn render_name(result: ResultName) -> RenderResult {
-///     let (repeat, name) = result.inner;
+///     let (repeat, name) = result.0;
 ///     let mut render_result = RenderResult::new();
 ///     let mut parts = Vec::with_capacity(repeat as usize);
 ///     for _ in 0..repeat {
@@ -1215,35 +1236,41 @@ pub mod example_enum_tag {}
 /// dispatcher!("hello", EntryHello);
 ///
 /// // Define error types
-/// pack!(ErrorNoNameProvided = ());
-/// pack!(ErrorNameTooLong = u16);
-/// pack!(ErrorNameNotAvailable = ());
+/// #[derive(Grouped)]
+/// pub struct ErrorNoNameProvided;
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct ErrorNameTooLong(u16);
+///
+/// #[derive(Grouped)]
+/// pub struct ErrorNameNotAvailable;
 ///
 /// // Define success type
-/// pack!(ResultName = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
 ///
 /// // Pre-registered names
 /// static VEC_REGISTERED_NAMES: &[&str] = &["Alice", "Bob", "Charlie", "David", "Eve"];
 ///
 /// #[chain]
 /// fn handle_hello(args: EntryHello) -> Next {
-///     let Some(name) = args.inner.first().cloned() else {
+///     let Some(name) = args.0.first().cloned() else {
 ///         // If no name is provided, pass ErrorNoNameProvided
-///         return ErrorNoNameProvided::default().to_render();
+///         return ErrorNoNameProvided.to_render();
 ///     };
 ///
 ///     if name.len() > 10 {
 ///         // If the name is too long, pass ErrorNameTooLong
-///         return ErrorNameTooLong::new(name.len() as u16).to_render();
+///         return ErrorNameTooLong(name.len() as u16).to_render();
 ///     }
 ///
 ///     if VEC_REGISTERED_NAMES.contains(&name.as_str()) {
 ///         // If the name already exists, pass ErrorNameNotAvailable
-///         return ErrorNameNotAvailable::default().to_render();
+///         return ErrorNameNotAvailable.to_render();
 ///     }
 ///
 ///     // If the name is valid, pass ResultName
-///     ResultName::new(name).to_render()
+///     ResultName(name).to_render()
 /// }
 ///
 /// /// Renders a successful greeting with the given name.
@@ -1282,12 +1309,7 @@ pub mod example_enum_tag {}
 /// #[renderer]
 /// fn render_entry_fallback(err: EntryFallback) -> RenderResult {
 ///     let mut render_result = RenderResult::new();
-///     writeln!(
-///         render_result,
-///         "Command not found: \"{}\"",
-///         err.inner.join(" ")
-///     )
-///     .ok();
+///     writeln!(render_result, "Command not found: \"{}\"", err.0.join(" ")).ok();
 ///     render_result
 /// }
 ///
@@ -1351,18 +1373,21 @@ pub mod example_error_handling {}
 ///
 /// dispatcher!("hello", EntryHello);
 ///
-/// pack!(ErrorNoNameProvided = ());
-/// pack!(ResultName = String);
+/// #[derive(Grouped)]
+/// pub struct ErrorNoNameProvided;
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
 ///
 /// #[chain]
 /// fn handle_hello(args: EntryHello) -> Next {
-///     let Some(name) = args.inner.first().cloned() else {
+///     let Some(name) = args.0.first().cloned() else {
 ///         // If no name is provided, pass ErrorNoNameProvided
-///         return ErrorNoNameProvided::default().to_render();
+///         return ErrorNoNameProvided.to_render();
 ///     };
 ///
 ///     // If the name is valid, pass ResultName
-///     ResultName::new(name).to_render()
+///     ResultName(name).to_render()
 /// }
 ///
 /// /// Renders a successful greeting with the given name.
@@ -1527,12 +1552,13 @@ pub mod example_help {}
 ///     program.exec_and_exit();
 /// }
 ///
-/// pack!(ResultName = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
 ///
 /// #[chain]
 /// fn handle_greet(args: EntryGreet) -> Next {
 ///     let name: ResultName = args
-///         .inner
+///         .0
 ///         .first()
 ///         .cloned()
 ///         .unwrap_or_else(|| "World".to_string())
@@ -1656,7 +1682,8 @@ pub mod example_implicit_dispatcher {}
 /// dispatcher!("show", EntryShow);
 /// dispatcher!("none", EntryNone);
 ///
-/// pack!(ResultShow = BTreeMap<Key, Value>);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultShow(BTreeMap<Key, Value>);
 ///
 /// fn main() {
 ///     let mut program = ThisProgram::new();
@@ -1774,14 +1801,17 @@ pub mod example_lazy_resources {}
 /// }
 /// // --------- IMPORTANT ---------
 ///
-/// pack!(ResultName = String);
-/// pack!(DescResult = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct DescResult(String);
 ///
 /// /// Chain for `greet` — reads the name and produces a `ResultName`.
 /// #[chain]
 /// fn handle_greet(args: EntryGreet) -> Next {
 ///     let name: ResultName = args
-///         .inner
+///         .0
 ///         .first()
 ///         .cloned()
 ///         .unwrap_or_else(|| "World".to_string())
@@ -1799,7 +1829,7 @@ pub mod example_lazy_resources {}
 ///         None => "EntryGreet has no description".to_string(),
 ///     };
 ///     // --------- IMPORTANT ---------
-///     DescResult::new(msg).to_render()
+///     DescResult(msg).to_render()
 /// }
 ///
 /// /// Chain for `nodoc` — asks for metadata on an entry that has none.
@@ -1812,7 +1842,7 @@ pub mod example_lazy_resources {}
 ///         None => "EntryDescription has no description".to_string(),
 ///     };
 ///     // --------- IMPORTANT ---------
-///     DescResult::new(msg).to_render()
+///     DescResult(msg).to_render()
 /// }
 ///
 /// /// Renders the greeting message with the provided name.
@@ -1897,7 +1927,8 @@ pub mod example_metadata {}
 /// //                      you can use this syntax to create an alias simultaneously
 /// // --------- IMPORTANT ---------
 ///
-/// pack!(ParsedNumber = i32);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ParsedNumber(i32);
 ///
 /// /// Parse the first argument as an `i32`
 /// ///
@@ -1905,9 +1936,9 @@ pub mod example_metadata {}
 /// /// On failure, routes to `render_parse_error` via the registered outside type.
 /// #[chain]
 /// fn parse_number(args: EntryParse) -> Next {
-///     let input = args.inner.first().cloned().unwrap_or_default();
+///     let input = args.0.first().cloned().unwrap_or_default();
 ///     match input.parse::<i32>() {
-///         Ok(num) => ParsedNumber::new(num).to_chain(),
+///         Ok(num) => ParsedNumber(num).to_chain(),
 ///         Err(e) => e.to_chain(),
 ///     }
 /// }
@@ -1950,181 +1981,6 @@ pub mod example_metadata {}
 /// gen_program!();
 /// ```
 pub mod example_outside_type {}
-/// Example `pack_err!`
-///
-///  > This example demonstrates how to use the `pack_err!` macro to define error types
-///  > with automatic `name` field (set to snake_case at compile time) and optional `info` field.
-///  > Also demonstrates `--json` serialization when `structural_renderer` is enabled.
-///
-///  Run:
-///  ```bash
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find Cargo.toml
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find src
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural --json
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural Cargo.toml --json
-///  cargo run --manifest-path examples/example-pack-err/Cargo.toml --quiet -- find-structural src --json
-///  ```
-///
-///  Output:
-///  ```plaintext
-///  Search path not provided
-///  Not a directory: Cargo.toml
-///  Found directory: src
-///  {"name":"error_not_found"}
-///  {"name":"error_not_dir","info":"Cargo.toml"}
-///  {"inner":"src"}
-///  {"name":"error_not_found_structural"}
-///  {"name":"error_not_dir_structural","info":"Cargo.toml"}
-///  ```
-///
-/// Source code (./Cargo.toml)
-/// ```toml
-/// [package]
-/// name = "example-pack-err"
-/// version = "0.1.0"
-/// edition = "2024"
-///
-/// [dependencies]
-/// serde = { version = "1.0.228", features = ["derive"] }
-///
-/// [dependencies.mingling]
-/// path = "../../mingling"
-/// features = [
-///     "structural_renderer",
-///     "extras",
-/// ]
-///
-/// [workspace]
-/// ```
-///
-/// Source code (./src/main.rs)
-/// ```ignore
-/// use mingling::prelude::*;
-/// use mingling::setup::StructuralRendererSetup;
-/// use std::io::Write;
-/// use std::path::PathBuf;
-///
-/// dispatcher!("find", EntryFind);
-/// dispatcher!("find-structural", EntryFindStructural);
-///
-/// // --------- IMPORTANT ---------
-/// // `pack_err!` is a convenient macro for defining error types.
-/// //
-/// //     Simple form:         pack_err!(ErrorNotFound);
-/// //     Typed form:          pack_err!(ErrorNotDir = PathBuf);
-/// //
-/// // The simple form generates a struct with `name: String` and `impl Default`.
-/// //   name = "error_not_found"  (automatically snake_cased at compile time)
-/// //
-/// // The typed form additionally generates `pub fn new(info)`.
-/// //   name = "error_not_dir"
-/// //
-/// // When `structural_renderer` is enabled, the struct also gets
-/// // `#[derive(serde::Serialize)]` for --json / --yaml output.
-/// // --------- IMPORTANT ---------
-///
-/// // Simple form — name = "error_not_found"
-/// pack_err!(ErrorNotFound);
-///
-/// // Typed form — name = "error_not_dir"
-/// pack_err!(ErrorNotDir = PathBuf);
-///
-/// // Simple form — with StructuralData support for --json / --yaml
-/// pack_err_structural!(ErrorNotFoundStructural);
-///
-/// // Typed form — with StructuralData support for --json / --yaml
-/// pack_err_structural!(ErrorNotDirStructural = PathBuf);
-///
-/// // Success type with StructuralData support
-/// pack_structural!(ResultPath = PathBuf);
-///
-/// #[chain]
-/// fn handle_find(args: EntryFind) -> Next {
-///     let Some(path_str) = args.inner.first().cloned() else {
-///         // No path provided → use the simple error form (Default)
-///         return ErrorNotFound::default().to_render();
-///     };
-///
-///     let path = PathBuf::from(&path_str);
-///     if path.is_dir() {
-///         // Is a directory → success
-///         ResultPath::new(path).to_render()
-///     } else {
-///         // Not a directory (or doesn't exist) → use the typed error form
-///         ErrorNotDir::new(path).to_render()
-///     }
-/// }
-///
-/// #[chain]
-/// fn handle_find_structural(args: EntryFindStructural) -> Next {
-///     let Some(path_str) = args.inner.first().cloned() else {
-///         // No path provided → use the simple error form (Default)
-///         return ErrorNotFoundStructural::default().to_render();
-///     };
-///
-///     let path = PathBuf::from(&path_str);
-///     if path.is_dir() {
-///         // Is a directory → success
-///         ResultPath::new(path).to_render()
-///     } else {
-///         // Not a directory (or doesn't exist) → use the typed error form
-///         ErrorNotDirStructural::new(path).to_render()
-///     }
-/// }
-///
-/// /// Renders the successful result with the found directory path.
-/// #[renderer]
-/// fn render_result_path(path: ResultPath) -> RenderResult {
-///     let mut render_result = RenderResult::new();
-///     writeln!(render_result, "Found directory: {}", path.display()).ok();
-///     render_result
-/// }
-///
-/// /// Renders the error when no search path is provided.
-/// #[renderer]
-/// fn render_error_not_found(_: ErrorNotFound) -> RenderResult {
-///     let mut render_result = RenderResult::new();
-///     writeln!(render_result, "Search path not provided").ok();
-///     render_result
-/// }
-///
-/// /// Renders the error when the given path is not a directory.
-/// #[renderer]
-/// fn render_error_not_dir(err: ErrorNotDir) -> RenderResult {
-///     let mut render_result = RenderResult::new();
-///     writeln!(render_result, "Not a directory: {}", err.info.display()).ok();
-///     render_result
-/// }
-///
-/// /// Renders the structural error when no search path is provided.
-/// #[renderer]
-/// fn render_error_not_found_structural(_: ErrorNotFoundStructural) -> RenderResult {
-///     let mut render_result = RenderResult::new();
-///     writeln!(render_result, "Search path not provided").ok();
-///     render_result
-/// }
-///
-/// /// Renders the structural error when the given path is not a directory.
-/// #[renderer]
-/// fn render_error_not_dir_structural(err: ErrorNotDirStructural) -> RenderResult {
-///     let mut render_result = RenderResult::new();
-///     writeln!(render_result, "Not a directory: {}", err.info.display()).ok();
-///     render_result
-/// }
-///
-/// gen_program!();
-///
-/// fn main() {
-///     let mut program = ThisProgram::new();
-///
-///     // Add StructuralRendererSetup to support --json / --yaml flags
-///     program.with_setup(StructuralRendererSetup);
-///
-///     let _ = program.exec();
-/// }
-/// ```
-pub mod example_pack_err {}
 /// Example Panic Unwind
 ///
 ///  > This example introduces how to catch Panic in the Mingling program loop
@@ -2171,7 +2027,9 @@ pub mod example_pack_err {}
 /// use std::io::Write;
 ///
 /// dispatcher!("panic", EntryPanic);
-/// pack!(NotPanic = ());
+///
+/// #[derive(Grouped)]
+/// pub struct NotPanic;
 ///
 /// fn main() {
 ///     let mut program = ThisProgram::new();
@@ -2198,7 +2056,7 @@ pub mod example_pack_err {}
 ///             // Panic happens here, will be caught
 ///             panic!("{}", s)
 ///         }
-///         None => NotPanic::default().into(),
+///         None => NotPanic.into(),
 ///     }
 /// }
 ///
@@ -2364,7 +2222,8 @@ pub mod example_pathfinder {}
 /// }
 ///
 /// // Create error route
-/// pack!(ErrorDirectoryNotExist = PathBuf);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ErrorDirectoryNotExist(PathBuf);
 ///
 /// // Create commands: cd ls exit
 /// dispatcher!("cd", EntryCd);
@@ -2373,16 +2232,18 @@ pub mod example_pathfinder {}
 /// dispatcher!("clear", EntryClear);
 ///
 /// // Define data needed for the cd command's execution phase
-/// pack!(StateChangeDirectory = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct StateChangeDirectory(String);
 ///
 /// // Define data needed for the ls command's rendering phase
-/// pack!(ResultList = Vec<String>);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultList(Vec<String>);
 ///
 /// // Parse cd command arguments
 /// #[chain]
 /// fn parse_cd_args(prev: EntryCd) -> Next {
 ///     let join = prev.pick_or_default(&arg![String]).unwrap();
-///     StateChangeDirectory::new(join).into()
+///     StateChangeDirectory(join).into()
 /// }
 ///
 /// // Execute directory change
@@ -2390,12 +2251,12 @@ pub mod example_pathfinder {}
 /// fn handle_cd(prev: StateChangeDirectory, current_dir: &mut ResCurrentDir) -> Next {
 ///     use just_fmt::fmt_path::fmt_path;
 ///
-///     let join = prev.inner;
+///     let join = prev.0;
 ///     let new_dir = fmt_path(current_dir.dir.join(join)).unwrap_or_default();
 ///
 ///     // If the path is not found, route to error handling
 ///     if !new_dir.exists() {
-///         return ErrorDirectoryNotExist::new(new_dir).to_render();
+///         return ErrorDirectoryNotExist(new_dir).to_render();
 ///     }
 ///
 ///     current_dir.dir = new_dir;
@@ -2420,14 +2281,14 @@ pub mod example_pathfinder {}
 ///         .collect();
 ///
 ///     // Render ResultList
-///     ResultList::new(entries).to_render()
+///     ResultList(entries).to_render()
 /// }
 ///
 /// /// Render ResultList data
 /// #[renderer]
 /// fn render_list(list: ResultList) -> RenderResult {
 ///     let mut render_result = RenderResult::new();
-///     for item in list.inner {
+///     for item in list.0 {
 ///         writeln!(render_result, "{}", item).ok();
 ///     }
 ///     render_result
@@ -2454,12 +2315,7 @@ pub mod example_pathfinder {}
 /// #[renderer]
 /// fn render_error_directory_not_exist(err: ErrorDirectoryNotExist) -> RenderResult {
 ///     let mut render_result = RenderResult::new();
-///     writeln!(
-///         render_result,
-///         "Directory not found: {}",
-///         err.inner.display()
-///     )
-///     .ok();
+///     writeln!(render_result, "Directory not found: {}", err.0.display()).ok();
 ///     render_result
 /// }
 ///
@@ -2636,13 +2492,14 @@ pub mod example_resources {}
 ///
 /// dispatcher!("greet", EntryGreet);
 ///
-/// pack!(ResultGreeting = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultGreeting(String);
 ///
 /// /// Chain: reads the `ResAppName` and `ResAppVersion` resources.
 /// #[chain]
 /// fn handle_greet(args: EntryGreet, app: &ResAppName, version: &ResAppVersion) -> Next {
 ///     let who = args
-///         .inner
+///         .0
 ///         .first()
 ///         .cloned()
 ///         .unwrap_or_else(|| "World".to_string());
@@ -2718,7 +2575,8 @@ pub mod example_setup {}
 /// }
 ///
 /// // --------- IMPORTANT ---------
-/// // For beautiful output structure, do not use `pack!` to wrap the types that need to be output.
+/// // For beautiful output structure, do not wrap the types that need to be output
+/// // in a newtype; instead, use a named struct.
 /// // Instead, manually implement
 /// //        ____________________________________ Mark as structured data so it can be rendered
 /// //       /                ____________________ Implement serde::Serialize
@@ -2734,7 +2592,7 @@ pub mod example_setup {}
 /// }
 /// // This will output: {"member_name":"name","member_age":32} structure
 ///
-/// // If using pack!(Info = (String, i32));
+/// // If wrapping with a tuple newtype (e.g. `#[derive(Grouped, Wrap)] pub struct Info((String, i32));`)
 /// // Output: {"inner":["name", 32]}
 ///
 /// // --------- IMPORTANT ---------
@@ -2812,30 +2670,30 @@ pub mod example_structural_renderer {}
 ///         let hello_with_valid_name = handle_hello(entry!("Peter")).into();
 ///         assert_render_result!(hello_with_valid_name);
 ///         let result_name = unpack_chain_process!(hello_with_valid_name, ResultName);
-///         assert_eq!(result_name.inner, "Peter");
+///         assert_eq!(result_name.0, "Peter");
 ///     }
 ///
 ///     #[test]
 ///     fn test_render_result_name() {
-///         let r = render_result_name(ResultName::new("Peter".into()));
+///         let r = render_result_name(ResultName("Peter".into()));
 ///         assert_eq!(r.to_string().as_str(), "Hello, Peter!")
 ///     }
 ///
 ///     #[test]
 ///     fn test_render_error_no_name_provided() {
-///         let r = render_error_no_name_provided(ErrorNoNameProvided::default());
+///         let r = render_error_no_name_provided(ErrorNoNameProvided);
 ///         assert_eq!(r.to_string().as_str(), "No name provided")
 ///     }
 ///
 ///     #[test]
 ///     fn test_render_error_name_not_available() {
-///         let r = render_error_name_not_available(ErrorNameNotAvailable::default());
+///         let r = render_error_name_not_available(ErrorNameNotAvailable);
 ///         assert_eq!(r.to_string().as_str(), "Name not available")
 ///     }
 ///
 ///     #[test]
 ///     fn test_render_error_name_too_long() {
-///         let r = render_error_name_too_long(ErrorNameTooLong::new(17));
+///         let r = render_error_name_too_long(ErrorNameTooLong(17));
 ///         assert_eq!(r.to_string().as_str(), "Name too long: 17 > 10")
 ///     }
 ///     // --------- IMPORTANT ---------
@@ -2843,29 +2701,35 @@ pub mod example_structural_renderer {}
 ///
 /// dispatcher!("hello", EntryHello);
 ///
-/// pack!(ErrorNoNameProvided = ());
-/// pack!(ErrorNameTooLong = u16);
-/// pack!(ErrorNameNotAvailable = ());
+/// #[derive(Grouped)]
+/// pub struct ErrorNoNameProvided;
+///
+/// #[derive(Grouped, Wrap)]
+/// pub struct ErrorNameTooLong(u16);
+///
+/// #[derive(Grouped)]
+/// pub struct ErrorNameNotAvailable;
 ///
-/// pack!(ResultName = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct ResultName(String);
 ///
 /// static VEC_REGISTERED_NAMES: &[&str] = &["Alice", "Bob", "Charlie", "David", "Eve"];
 ///
 /// #[chain]
 /// fn handle_hello(args: EntryHello) -> Next {
-///     let Some(name) = args.inner.first().cloned() else {
-///         return ErrorNoNameProvided::default().to_render();
+///     let Some(name) = args.0.first().cloned() else {
+///         return ErrorNoNameProvided.to_render();
 ///     };
 ///
 ///     if name.len() > 10 {
-///         return ErrorNameTooLong::new(name.len() as u16).to_render();
+///         return ErrorNameTooLong(name.len() as u16).to_render();
 ///     }
 ///
 ///     if VEC_REGISTERED_NAMES.contains(&name.as_str()) {
-///         return ErrorNameNotAvailable::default().to_render();
+///         return ErrorNameNotAvailable.to_render();
 ///     }
 ///
-///     ResultName::new(name).to_render()
+///     ResultName(name).to_render()
 /// }
 ///
 /// /// Renders a successful greeting with the given name.
@@ -2904,12 +2768,7 @@ pub mod example_structural_renderer {}
 /// #[renderer]
 /// fn render_entry_fallback(err: EntryFallback) -> RenderResult {
 ///     let mut render_result = RenderResult::new();
-///     writeln!(
-///         render_result,
-///         "Command not found: \"{}\"",
-///         err.inner.join(" ")
-///     )
-///     .ok();
+///     writeln!(render_result, "Command not found: \"{}\"", err.0.join(" ")).ok();
 ///     render_result
 /// }
 ///
diff --git a/mingling/src/gen_program.rs b/mingling/src/gen_program.rs
index 2c476a2..ed60668 100644
--- a/mingling/src/gen_program.rs
+++ b/mingling/src/gen_program.rs
@@ -12,7 +12,7 @@ pub type Next = ChainProcess<ThisProgram>;
 
 /// The generic program entry point.
 ///
-/// This type is created by the `pack!` macro as a variant of the
+/// This type is generated by the `gen_program!` macro as a variant of the
 /// program's output type set (`ThisProgram`).
 pub struct Entry {
     /// The arguments provided by the user
@@ -41,7 +41,7 @@ pub enum ThisProgram {
 
 /// A struct representing a "renderer not found" error.
 ///
-/// This type is created by the `pack!` macro as a variant of the
+/// This type is generated by the `gen_program!` macro as a variant of the
 /// program's output type set (`ThisProgram`).
 pub struct ErrorRendererNotFound {
     /// The name of the renderer that was not found
@@ -50,7 +50,7 @@ pub struct ErrorRendererNotFound {
 
 /// A struct representing a "dispatcher not found" error.
 ///
-/// This type is created by the `pack!` macro as a variant of the
+/// This type is generated by the `gen_program!` macro as a variant of the
 /// program's output type set (`ThisProgram`).
 pub struct EntryFallback {
     /// The arguments provided by the user
@@ -61,8 +61,6 @@ pub struct EntryFallback {
 pub struct ResultEmpty;
 
 /// A dispatcher representing the subcommand `__comp` itself.
-///
-/// **You can register it using `with_dispatcher`.**
 #[cfg(feature = "comp")]
 pub struct CMDCompletion;
 
@@ -71,7 +69,7 @@ pub struct CMDCompletion;
 /// This struct holds the raw command-line arguments that were passed to the `__comp`
 /// subcommand, which will be used to compute completion suggestions.
 ///
-/// This type is created by the `pack!` macro as a variant of the
+/// This type is generated by the `gen_program!` macro as a variant of the
 /// program's output type set (`ThisProgram`).
 #[cfg(feature = "comp")]
 pub struct CompletionContext {
@@ -85,7 +83,7 @@ pub struct CompletionContext {
 /// which together provide the information needed to render completion candidates
 /// to the user's shell.
 ///
-/// This type is created by the `pack!` macro as a variant of the
+/// This type is generated by the `gen_program!` macro as a variant of the
 /// program's output type set (`ThisProgram`).
 #[cfg(feature = "comp")]
 pub struct CompletionSuggest {
diff --git a/mingling/src/lib.rs b/mingling/src/lib.rs
index 6a7074b..55240e5 100644
--- a/mingling/src/lib.rs
+++ b/mingling/src/lib.rs
@@ -51,7 +51,7 @@ pub mod consts {
 ///
 /// This module re-exports all macros provided by the `mingling_macros` crate,
 /// including `dispatcher!`, `chain!`, `renderer!`,
-/// `gen_program!`, `pack!`, and many others. These macros form the core
+/// `gen_program!`, and many others. These macros form the core
 /// building blocks of the Mingling framework.
 ///
 /// For detailed documentation, usage examples, and the full list of available
@@ -84,13 +84,6 @@ pub mod macros {
     pub use mingling_macros::help;
     pub use mingling_macros::metadata;
     pub use mingling_macros::mlint;
-    pub use mingling_macros::pack;
-    #[cfg(feature = "extras")]
-    pub use mingling_macros::pack_err;
-    #[cfg(all(feature = "structural_renderer", feature = "extras"))]
-    pub use mingling_macros::pack_err_structural;
-    #[cfg(feature = "structural_renderer")]
-    pub use mingling_macros::pack_structural;
     #[cfg(feature = "comp")]
     #[doc(hidden)]
     pub use mingling_macros::program_comp_gen;
@@ -212,19 +205,7 @@ pub mod prelude {
     #[cfg(feature = "macros")]
     pub use crate::macros::gen_program;
     #[cfg(feature = "macros")]
-    pub use crate::macros::pack;
-    #[cfg(all(feature = "extras", feature = "macros"))]
-    pub use crate::macros::pack_err;
-    #[cfg(feature = "macros")]
     pub use crate::macros::renderer;
-    #[cfg(all(
-        feature = "macros",
-        feature = "structural_renderer",
-        feature = "extras"
-    ))]
-    pub use mingling_macros::pack_err_structural;
-    #[cfg(all(feature = "macros", feature = "structural_renderer"))]
-    pub use mingling_macros::pack_structural;
     pub use mingling_macros::r_append;
     pub use mingling_macros::r_eprint;
     pub use mingling_macros::r_eprintln;
diff --git a/mingling_cli/src/config/cmd_cfg.rs b/mingling_cli/src/config/cmd_cfg.rs
index c10195e..8baa4a1 100644
--- a/mingling_cli/src/config/cmd_cfg.rs
+++ b/mingling_cli/src/config/cmd_cfg.rs
@@ -1,8 +1,6 @@
 use mingling::{
-    LazyRes, Routable, ShellContext, Suggest,
-    macros::{
-        arg, buffer, chain, command, completion, metadata, pack, r_println, renderer, suggest,
-    },
+    Grouped, LazyRes, Routable, ShellContext, Suggest, Wrap,
+    macros::{arg, buffer, chain, command, completion, metadata, r_println, renderer, suggest},
     metadata::Description,
     picker::{EntryPicker, PickerArg, value::Flag},
 };
@@ -11,10 +9,17 @@ use crate::{Entry, Next, config::ResMlingConfig};
 
 const FLAG_PAIR: PickerArg<Flag> = arg![pair: Flag];
 
-pack!(StateConfigEdit = (String, String));
-pack!(ResultConfigKeyValuePair = String);
-pack!(ResultConfigValue = String);
-pack!(ResultConfig = ());
+#[derive(Grouped, Wrap)]
+pub struct StateConfigEdit((String, String));
+
+#[derive(Grouped, Wrap)]
+pub struct ResultConfigKeyValuePair(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ResultConfigValue(String);
+
+#[derive(Grouped)]
+pub struct ResultConfig;
 
 #[command]
 pub fn cfg(args: Entry) -> Next {
@@ -27,19 +32,19 @@ pub fn cfg(args: Entry) -> Next {
     match (key, value) {
         (Some(k), Some(v)) => {
             // Edit
-            StateConfigEdit::new((k, v)).into()
+            StateConfigEdit((k, v)).into()
         }
         (Some(k), None) => {
             // Display
             if *show_pair {
-                ResultConfigKeyValuePair::new(k).to_render()
+                ResultConfigKeyValuePair(k).to_render()
             } else {
-                ResultConfigValue::new(k).to_render()
+                ResultConfigValue(k).to_render()
             }
         }
         (None, None) => {
             // List
-            ResultConfig::new(()).to_render()
+            ResultConfig.to_render()
         }
         _ => {
             unreachable!("This path is unreachable given the positional parsing done by arg-picker")
@@ -50,13 +55,13 @@ pub fn cfg(args: Entry) -> Next {
 #[chain]
 pub fn handle_state_config_edit(kv: StateConfigEdit, config: &mut LazyRes<ResMlingConfig>) {
     let config = config.get_mut();
-    config.edit(&kv.0, &kv.1);
+    config.edit(&kv.0.0, &kv.0.1);
 }
 
 #[renderer(buffer)]
 pub fn render_config_kvp(r: ResultConfigKeyValuePair, config: &mut LazyRes<ResMlingConfig>) {
     let config = config.get_ref();
-    let key = r.inner;
+    let key = r.0;
     let value = config.get(&key);
     r_println!(
         "\"{}\" = \"{}\"",
@@ -68,7 +73,7 @@ pub fn render_config_kvp(r: ResultConfigKeyValuePair, config: &mut LazyRes<ResMl
 #[renderer(buffer)]
 pub fn render_config_value(r: ResultConfigValue, config: &mut LazyRes<ResMlingConfig>) {
     let config = config.get_ref();
-    let key = r.inner;
+    let key = r.0;
     let value = config.get(&key);
     r_println!("{}", value)
 }
diff --git a/mingling_cli/src/lib.rs b/mingling_cli/src/lib.rs
index 902ab32..e82300e 100644
--- a/mingling_cli/src/lib.rs
+++ b/mingling_cli/src/lib.rs
@@ -45,7 +45,7 @@ pub fn complete_global(_ctx: &ShellContext) -> Suggest {
 #[renderer]
 pub fn handle_fallback(args: EntryFallback) -> RenderResult {
     let mut r = RenderResult::new();
-    let args = args.inner;
+    let args = args.0;
     if !args.is_empty() {
         eprintln_cargo!(
             r,
diff --git a/mingling_cli/src/linter/cmd_explain.rs b/mingling_cli/src/linter/cmd_explain.rs
index 5346255..923e890 100644
--- a/mingling_cli/src/linter/cmd_explain.rs
+++ b/mingling_cli/src/linter/cmd_explain.rs
@@ -1,10 +1,7 @@
 use crate::{Next, eprintln_cargo, linter::registry::ResLintRegistry};
 use mingling::{
-    Grouped, LazyRes, RenderResult, Routable, ShellContext, Suggest, SuggestItem,
-    macros::{
-        arg, buffer, chain, completion, dispatcher, metadata, pack, pack_err, r_println, renderer,
-        routeify,
-    },
+    Grouped, LazyRes, RenderResult, Routable, ShellContext, Suggest, SuggestItem, Wrap,
+    macros::{arg, buffer, chain, completion, dispatcher, metadata, r_println, renderer, routeify},
     metadata::Description,
     picker::EntryPicker,
 };
@@ -16,9 +13,14 @@ pub fn desc_explain() -> Description {
     "Explain the meaning of the specified Lint".into()
 }
 
-pack!(StateExplainLint = String);
-pack_err!(ErrorNoExplainLintProvided);
-pack_err!(ErrorNoSuchLint = String);
+#[derive(Grouped, Wrap)]
+pub struct StateExplainLint(String);
+
+#[derive(Grouped, Default)]
+pub struct ErrorNoExplainLintProvided;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorNoSuchLint(String);
 
 #[derive(Debug, Default, Grouped)]
 pub struct ResultExplainLint {
@@ -33,11 +35,9 @@ pub struct ResultExplainLint {
 #[chain(routeify)]
 pub fn handle_explain(args: EntryExplain) -> Next {
     let lint_name = args
-        .pick_or_route(&arg![String], || {
-            ErrorNoExplainLintProvided::default().to_chain()
-        })
+        .pick_or_route(&arg![String], || ErrorNoExplainLintProvided.to_chain())
         .to_result()?;
-    StateExplainLint::new(lint_name).into()
+    StateExplainLint(lint_name).into()
 }
 
 #[chain]
@@ -46,9 +46,9 @@ pub fn handle_state_explain_lint(
     registry: &mut LazyRes<ResLintRegistry>,
 ) -> Next {
     let registry = registry.get_ref();
-    let lint_name = p.inner;
+    let lint_name = p.0;
     let Some(entry) = registry.lints.iter().find(|l| l.name == lint_name) else {
-        return ErrorNoSuchLint::new(lint_name).to_chain();
+        return ErrorNoSuchLint(lint_name).to_chain();
     };
     ResultExplainLint {
         lint_name: entry.name.clone(),
@@ -87,7 +87,7 @@ pub fn render_error_no_such_lint(
 ) -> RenderResult {
     let mut r = RenderResult::new();
     let registry = registry.get_ref();
-    eprintln_cargo!(r, "No such lint: \"{}\"", err.info);
+    eprintln_cargo!(r, "No such lint: \"{}\"", err.0);
     r_println!(r, "");
     r_println!(r, "Available lints:");
     for entry in registry.lints.iter() {
diff --git a/mingling_cli/src/linter/cmd_lint.rs b/mingling_cli/src/linter/cmd_lint.rs
index 07c18c5..7cab63a 100644
--- a/mingling_cli/src/linter/cmd_lint.rs
+++ b/mingling_cli/src/linter/cmd_lint.rs
@@ -1,10 +1,11 @@
 use crate::linter::mlint_report::{MlintReport, StateLintReports};
 use cargo_metadata::Metadata;
 use mingling::consts::REMAINS;
-use mingling::macros::{arg, chain, completion, dispatcher, metadata, pack, suggest};
+use mingling::macros::{arg, chain, completion, dispatcher, metadata, suggest};
 use mingling::metadata::Description;
 use mingling::picker::parselib::ParserStyle;
 use mingling::picker::{EntryPicker, PickerArg};
+use mingling::{Grouped, Wrap};
 use mingling::{LazyRes, ShellContext, Suggest};
 use tokio::task::JoinSet;
 
@@ -77,7 +78,8 @@ async fn linter_main(metadata: &Metadata) -> Vec<MlintReport> {
     all_reports
 }
 
-pack!(StateBeginLinter = ());
+#[derive(Grouped, Wrap)]
+pub struct StateBeginLinter(());
 
 #[chain]
 pub fn handle_lint(args: EntryLint) -> StateBeginLinter {
@@ -88,7 +90,7 @@ pub fn handle_lint(args: EntryLint) -> StateBeginLinter {
 
     // If with_checker is not set, proceed directly to the mingling lint phase
     let Some(with_checker) = with_checker else {
-        return StateBeginLinter::new(());
+        return StateBeginLinter(());
     };
 
     let with_checker: Vec<&str> = with_checker.split(',').collect();
@@ -97,7 +99,7 @@ pub fn handle_lint(args: EntryLint) -> StateBeginLinter {
     // Run the outer checker (e.g. cargo check) with output passed through directly
     execute_checker(&with_checker, checker_args.as_slice());
 
-    StateBeginLinter::new(())
+    StateBeginLinter(())
 }
 
 /// Run the outer checker (e.g. cargo check) with output passed through directly.
@@ -135,7 +137,7 @@ pub async fn handle_state_begin_linter(
 ) -> StateLintReports {
     let metadata = metadata.get_ref().data();
     let reports = linter_main(metadata).await;
-    StateLintReports::new(reports)
+    StateLintReports(reports)
 }
 
 #[completion(EntryLint)]
diff --git a/mingling_cli/src/linter/mlint_report.rs b/mingling_cli/src/linter/mlint_report.rs
index b594b9d..d7bf652 100644
--- a/mingling_cli/src/linter/mlint_report.rs
+++ b/mingling_cli/src/linter/mlint_report.rs
@@ -9,8 +9,8 @@ use cargo_metadata::{Message, PackageId};
 
 use annotate_snippets::level::{ERROR, HELP, NOTE, WARNING};
 use annotate_snippets::{AnnotationKind, Group, Patch, Renderer, Snippet};
-use mingling::macros::{buffer, chain, pack, r_append, r_eprintln, renderer};
-use mingling::{RendererInvoker, Routable};
+use mingling::macros::{buffer, chain, r_append, r_eprintln, renderer};
+use mingling::{Grouped, RendererInvoker, Routable, Wrap};
 
 use crate::Next;
 use crate::metadata::setup::ResUsingJson;
@@ -416,22 +416,25 @@ impl MlintReport {
     }
 }
 
-pack!(StateLintReports = Vec<MlintReport>);
-pack!(ResultLintReportsAnnotateSnippet = Vec<MlintReport>);
-pack!(ResultLintReportsJson = Vec<MlintReport>);
+#[derive(Grouped, Wrap)]
+pub struct StateLintReports(pub Vec<MlintReport>);
+#[derive(Grouped, Wrap)]
+pub struct ResultLintReportsAnnotateSnippet(Vec<MlintReport>);
+#[derive(Grouped, Wrap)]
+pub struct ResultLintReportsJson(Vec<MlintReport>);
 
 #[chain]
 pub fn handle_state_lint_reports(reports: StateLintReports, using_json: &ResUsingJson) -> Next {
     if using_json.using {
-        ResultLintReportsJson::new(reports.inner).to_render()
+        ResultLintReportsJson(reports.0).to_render()
     } else {
-        ResultLintReportsAnnotateSnippet::new(reports.inner).to_render()
+        ResultLintReportsAnnotateSnippet(reports.0).to_render()
     }
 }
 
 #[renderer(buffer)]
 pub fn render_lint_reports(reports: ResultLintReportsAnnotateSnippet) {
-    for report in reports.inner {
+    for report in reports.0 {
         r_eprintln!("{}", report.to_annotate_snippet_render());
     }
 }
@@ -441,7 +444,7 @@ pub fn render_lint_reports_json(
     reports: ResultLintReportsJson,
     message_renderer: &RendererInvoker<Message>,
 ) {
-    for report in reports.inner {
+    for report in reports.0 {
         let message = report.to_compiler_message();
         let result = message_renderer.invoke(message);
         r_append!(result);
diff --git a/mingling_cli/src/metadata/cmd_metadata.rs b/mingling_cli/src/metadata/cmd_metadata.rs
index 3ee9f09..7f8d4ad 100644
--- a/mingling_cli/src/metadata/cmd_metadata.rs
+++ b/mingling_cli/src/metadata/cmd_metadata.rs
@@ -1,7 +1,7 @@
 use cargo_metadata::Metadata;
 use mingling::{
-    LazyRes,
-    macros::{chain, dispatcher, metadata, pack},
+    Grouped, LazyRes, Wrap,
+    macros::{chain, dispatcher, metadata},
     metadata::Description,
 };
 
@@ -16,7 +16,8 @@ pub fn desc_metadata() -> Description {
         .into()
 }
 
-pack!(ResultMetadata = ResMetadata);
+#[derive(Grouped, Wrap)]
+pub struct ResultMetadata(ResMetadata);
 
 #[chain]
 pub fn handle_metadata(_: EntryMetadata, metadata: &mut LazyRes<ResMetadata>) -> Metadata {
diff --git a/mingling_cli/src/pkg_mgr.rs b/mingling_cli/src/pkg_mgr.rs
index e140991..8493804 100644
--- a/mingling_cli/src/pkg_mgr.rs
+++ b/mingling_cli/src/pkg_mgr.rs
@@ -8,16 +8,23 @@ pub mod cmd_uninstall;
 use std::path::PathBuf;
 
 use mingling::{
-    Program, RenderResult,
-    macros::{pack_err, program_setup, r_println, renderer},
+    Grouped, Program, RenderResult, Wrap,
+    macros::{program_setup, r_println, renderer},
 };
 
 use crate::{ThisProgram, eprintln_cargo, hprintln_cargo};
 
-pack_err!(ErrorRootPackageNotFound);
-pack_err!(ErrorNoDataDirectory);
-pack_err!(ErrorPackageSpecInvalid = String);
-pack_err!(ErrorPackageNameRequired);
+#[derive(Grouped, Default)]
+pub struct ErrorRootPackageNotFound;
+
+#[derive(Grouped, Default)]
+pub struct ErrorNoDataDirectory;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorPackageSpecInvalid(String);
+
+#[derive(Grouped, Default)]
+pub struct ErrorPackageNameRequired;
 
 /// The `mingling/packages` packages directory under the user's data directory.
 #[derive(Debug, Default, Clone)]
@@ -55,7 +62,7 @@ pub fn render_error_no_data_directory(_: ErrorNoDataDirectory) -> RenderResult {
 #[renderer]
 pub fn render_error_package_spec_invalid(err: ErrorPackageSpecInvalid) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "invalid package spec: {}", err.info);
+    eprintln_cargo!(r, "invalid package spec: {}", err.0);
     r
 }
 
diff --git a/mingling_cli/src/pkg_mgr/cmd_install.rs b/mingling_cli/src/pkg_mgr/cmd_install.rs
index 731ba98..8b2f3b7 100644
--- a/mingling_cli/src/pkg_mgr/cmd_install.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_install.rs
@@ -2,8 +2,8 @@ use std::{env, fs, io, path::PathBuf, process::Command};
 
 use cargo_metadata::TargetKind;
 use mingling::{
-    Grouped, LazyRes, RenderResult, Routable, ShellContext, Suggest,
-    macros::{arg, chain, command, completion, metadata, pack_err, renderer, routeify, suggest},
+    Grouped, LazyRes, RenderResult, Routable, ShellContext, Suggest, Wrap,
+    macros::{arg, chain, command, completion, metadata, renderer, routeify, suggest},
     metadata::Description,
     picker::{EntryPicker, PickerArg, value::Flag},
 };
@@ -15,9 +15,14 @@ use crate::{
     println_cargo,
 };
 
-pack_err!(ErrorBuildFailed = String);
-pack_err!(ErrorBinaryNotFound = String);
-pack_err!(ErrorPkgEnableFailed = String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorBuildFailed(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorBinaryNotFound(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorPkgEnableFailed(String);
 
 /// Flag: `--enable` — run `mling pkg-enable` after a successful install
 /// to enable the package being installed.
@@ -75,13 +80,13 @@ pub fn install(
     let metadata = metadata.get_ref().data();
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let root_package = metadata
         .root_package()
         .or_else(|| metadata.workspace_packages().first().copied())
-        .ok_or(ErrorRootPackageNotFound::default())?;
+        .ok_or(ErrorRootPackageNotFound)?;
 
     StateInstallBuild {
         workspace_root: metadata.workspace_root.clone().into_std_path_buf(),
@@ -103,11 +108,9 @@ pub fn handle_state_install_build(state: StateInstallBuild) -> Next {
         .args(["build", "--release"])
         .current_dir(&state.workspace_root)
         .status()
-        .map_err(|e| {
-            ErrorBuildFailed::new(format!("failed to run `cargo build --release`: {e}"))
-        })?;
+        .map_err(|e| ErrorBuildFailed(format!("failed to run `cargo build --release`: {e}")))?;
     if !status.success() {
-        return ErrorBuildFailed::new(format!("`cargo build --release` failed with {status}"))
+        return ErrorBuildFailed(format!("`cargo build --release` failed with {status}"))
             .to_chain();
     }
 
@@ -146,7 +149,7 @@ pub fn handle_state_install_copy(
             let bin_file = format!("{}{}", target.name, state.exe_suffix);
             let src = state.release_dir.join(&bin_file);
             if !src.is_file() {
-                return ErrorBinaryNotFound::new(bin_file).to_chain();
+                return ErrorBinaryNotFound(bin_file).to_chain();
             }
             let dst = state.install_dir.join(&bin_file);
             fs::copy(&src, &dst).map_err(|e| {
@@ -181,7 +184,7 @@ pub fn handle_state_install_copy(
         let root_package = metadata
             .root_package()
             .or_else(|| metadata.workspace_packages().first().copied())
-            .ok_or(ErrorRootPackageNotFound::default())?;
+            .ok_or(ErrorRootPackageNotFound)?;
         return StateInstallEnable {
             install_dir: state.install_dir,
             installed: state.installed,
@@ -207,13 +210,11 @@ pub fn handle_state_install_enable(state: StateInstallEnable) -> Next {
         .args(["pkg-enable", &spec])
         .status()
         .map_err(|e| {
-            ErrorPkgEnableFailed::new(format!("failed to run `mling pkg-enable {spec}`: {e}"))
+            ErrorPkgEnableFailed(format!("failed to run `mling pkg-enable {spec}`: {e}"))
         })?;
     if !status.success() {
-        return ErrorPkgEnableFailed::new(format!(
-            "`mling pkg-enable {spec}` failed with {status}"
-        ))
-        .to_chain();
+        return ErrorPkgEnableFailed(format!("`mling pkg-enable {spec}` failed with {status}"))
+            .to_chain();
     }
 
     ResultInstall {
@@ -236,21 +237,21 @@ pub fn render_result_install(result: ResultInstall) -> RenderResult {
 #[renderer]
 pub fn render_error_build_failed(err: ErrorBuildFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_binary_not_found(err: ErrorBinaryNotFound) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "binary not found: {}", err.info);
+    eprintln_cargo!(r, "binary not found: {}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_pkg_enable_failed(err: ErrorPkgEnableFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
diff --git a/mingling_cli/src/pkg_mgr/cmd_internal_loadpkgs.rs b/mingling_cli/src/pkg_mgr/cmd_internal_loadpkgs.rs
index b4928ce..f0ac88a 100644
--- a/mingling_cli/src/pkg_mgr/cmd_internal_loadpkgs.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_internal_loadpkgs.rs
@@ -4,8 +4,8 @@ use std::{
 };
 
 use mingling::{
-    Routable,
-    macros::{buffer, command, pack, r_println, renderer, routeify},
+    Grouped, Routable, Wrap,
+    macros::{buffer, command, r_println, renderer, routeify},
 };
 
 use crate::{
@@ -14,16 +14,18 @@ use crate::{
 };
 
 // Version directory paths of every enabled package.
-pack!(ResultLoadPkgsPaths = Vec<PathBuf>);
+#[derive(Grouped, Wrap)]
+pub struct ResultLoadPkgsPaths(Vec<PathBuf>);
 
 // Completion script paths of every enabled package.
-pack!(ResultLoadPkgsComps = Vec<PathBuf>);
+#[derive(Grouped, Wrap)]
+pub struct ResultLoadPkgsComps(Vec<PathBuf>);
 
 #[command(node = "__loadpkgs_path", routeify)]
 pub fn load_packages_paths(packages_dir: &ResPackagesDir) -> Next {
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
     let paths = enabled_version_dirs(packages_dir).map_err(|e| {
         io::Error::new(
@@ -31,14 +33,14 @@ pub fn load_packages_paths(packages_dir: &ResPackagesDir) -> Next {
             format!("failed to read {}: {e}", packages_dir.display()),
         )
     })?;
-    ResultLoadPkgsPaths::new(paths).to_chain()
+    ResultLoadPkgsPaths(paths).to_chain()
 }
 
 #[command(node = "__loadpkgs_comp_scripts", routeify)]
 pub fn load_packages_comp_scripts(packages_dir: &ResPackagesDir) -> Next {
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
     let scripts = comp_scripts(packages_dir).map_err(|e| {
         io::Error::new(
@@ -46,19 +48,19 @@ pub fn load_packages_comp_scripts(packages_dir: &ResPackagesDir) -> Next {
             format!("failed to read {}: {e}", packages_dir.display()),
         )
     })?;
-    ResultLoadPkgsComps::new(scripts).to_chain()
+    ResultLoadPkgsComps(scripts).to_chain()
 }
 
 #[renderer(buffer)]
 pub fn render_result_load_pkgs_paths(r: ResultLoadPkgsPaths) {
-    for path in r.inner {
+    for path in r.0 {
         r_println!("{}", path.display());
     }
 }
 
 #[renderer(buffer)]
 pub fn render_result_load_pkgs_comps(r: ResultLoadPkgsComps) {
-    for path in r.inner {
+    for path in r.0 {
         r_println!("{}", path.display());
     }
 }
diff --git a/mingling_cli/src/pkg_mgr/cmd_pkg_disable.rs b/mingling_cli/src/pkg_mgr/cmd_pkg_disable.rs
index 041bb09..b4989eb 100644
--- a/mingling_cli/src/pkg_mgr/cmd_pkg_disable.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_pkg_disable.rs
@@ -1,8 +1,8 @@
 use std::{fs, io};
 
 use mingling::{
-    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem,
-    macros::{arg, chain, command, completion, metadata, pack, pack_err, renderer, routeify},
+    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem, Wrap,
+    macros::{arg, chain, command, completion, metadata, renderer, routeify},
     metadata::Description,
     picker::{EntryPicker, PickerArg},
 };
@@ -18,10 +18,12 @@ use crate::{
 /// Positional argument: package name
 pub static ARG_NAME: PickerArg<String> = arg![String];
 
-pack_err!(ErrorPackageNotEnabled = String);
+#[derive(Grouped, Wrap)]
+pub struct ErrorPackageNotEnabled(String);
 
 // The name of the package to disable
-pack!(StatePkgDisable = String);
+#[derive(Grouped, Wrap)]
+pub struct StatePkgDisable(String);
 
 #[derive(Debug, Default, Grouped)]
 pub struct ResultPkgDisable {
@@ -37,30 +39,30 @@ pub fn desc_pkg_disable() -> Description {
 #[command(node = "pkg-disable", routeify)]
 pub fn package_disable(args: EntryPkgDisable, packages_dir: &ResPackagesDir) -> Next {
     let name = args
-        .pick_or_route(&ARG_NAME, || ErrorPackageNameRequired::default().to_chain())
+        .pick_or_route(&ARG_NAME, || ErrorPackageNameRequired.to_chain())
         .to_result()?;
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
     if name.contains('/') || name.contains('\\') || name.contains("..") || name.contains('@') {
-        return ErrorPackageSpecInvalid::new(name).to_chain();
+        return ErrorPackageSpecInvalid(name).to_chain();
     }
 
-    StatePkgDisable::new(name).to_chain()
+    StatePkgDisable(name).to_chain()
 }
 
 #[chain(routeify)]
 pub fn handle_state_pkg_disable(p: StatePkgDisable, packages_dir: &ResPackagesDir) -> Next {
-    let name = p.inner;
+    let name = p.0;
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let file = packages_dir.join(&name);
     if !file.is_file() {
-        return ErrorPackageNotEnabled::new(name).to_chain();
+        return ErrorPackageNotEnabled(name).to_chain();
     }
     fs::remove_file(&file).map_err(|e| {
         io::Error::new(
@@ -86,7 +88,7 @@ pub fn render_result_pkg_disable(result: ResultPkgDisable) -> RenderResult {
 #[renderer]
 pub fn render_error_package_not_enabled(err: ErrorPackageNotEnabled) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "package is not enabled: {}", err.info);
+    eprintln_cargo!(r, "package is not enabled: {}", err.0);
     r
 }
 
diff --git a/mingling_cli/src/pkg_mgr/cmd_pkg_enable.rs b/mingling_cli/src/pkg_mgr/cmd_pkg_enable.rs
index 8f6a234..1235cd3 100644
--- a/mingling_cli/src/pkg_mgr/cmd_pkg_enable.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_pkg_enable.rs
@@ -1,8 +1,8 @@
 use std::{fs, io};
 
 use mingling::{
-    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem,
-    macros::{arg, chain, command, completion, metadata, pack, pack_err, renderer, routeify},
+    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem, Wrap,
+    macros::{arg, chain, command, completion, metadata, renderer, routeify},
     metadata::Description,
     picker::{EntryPicker, PickerArg},
 };
@@ -18,8 +18,11 @@ use crate::{
 /// Positional argument: package spec (`foo`, `foo@0`, `foo@0.1`, `foo@0.1.2`)
 pub static ARG_SPEC: PickerArg<String> = arg![String];
 
-pack_err!(ErrorNoMatchingVersion = String);
-pack!(StatePkgEnable = (String, String));
+#[derive(Grouped, Wrap)]
+pub struct ErrorNoMatchingVersion(String);
+
+#[derive(Grouped, Wrap)]
+pub struct StatePkgEnable((String, String));
 
 #[derive(Debug, Default, Grouped)]
 pub struct ResultPkgEnable {
@@ -35,14 +38,14 @@ pub fn desc_pkg_enable() -> Description {
 #[command(node = "pkg-enable", routeify)]
 pub fn package_enable(args: EntryPkgEnable, packages_dir: &ResPackagesDir) -> Next {
     let spec = args
-        .pick_or_route(&ARG_SPEC, || ErrorPackageNameRequired::default().to_chain())
+        .pick_or_route(&ARG_SPEC, || ErrorPackageNameRequired.to_chain())
         .to_result()?;
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
     if spec.contains('/') || spec.contains('\\') || spec.contains("..") {
-        return ErrorPackageSpecInvalid::new(spec).to_chain();
+        return ErrorPackageSpecInvalid(spec).to_chain();
     }
 
     let (name, version_part) = match spec.split_once('@') {
@@ -78,18 +81,18 @@ pub fn package_enable(args: EntryPkgEnable, packages_dir: &ResPackagesDir) -> Ne
     }
 
     let Some((_, version)) = candidates.into_iter().max_by(|a, b| a.1.cmp(&b.1)) else {
-        return ErrorNoMatchingVersion::new(spec).to_chain();
+        return ErrorNoMatchingVersion(spec).to_chain();
     };
 
-    StatePkgEnable::new((name, version.to_string())).to_chain()
+    StatePkgEnable((name, version.to_string())).to_chain()
 }
 
 #[chain(routeify)]
 pub fn handle_state_pkg_enable(p: StatePkgEnable, packages_dir: &ResPackagesDir) -> Next {
-    let (name, version) = p.inner;
+    let (name, version) = p.0;
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let file = packages_dir.join(&name);
@@ -110,7 +113,7 @@ pub fn render_result_pkg_enable(result: ResultPkgEnable) -> RenderResult {
 #[renderer]
 pub fn render_error_no_matching_version(err: ErrorNoMatchingVersion) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "no matching version for: {}", err.info);
+    eprintln_cargo!(r, "no matching version for: {}", err.0);
     r
 }
 
diff --git a/mingling_cli/src/pkg_mgr/cmd_pkg_show.rs b/mingling_cli/src/pkg_mgr/cmd_pkg_show.rs
index 88c79ef..ea26021 100644
--- a/mingling_cli/src/pkg_mgr/cmd_pkg_show.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_pkg_show.rs
@@ -3,7 +3,7 @@ use std::{collections::BTreeMap, fs, io};
 use colored::Colorize;
 use mingling::{
     Grouped, RenderResult, Routable,
-    macros::{buffer, command, metadata, pack_err, r_println, renderer, routeify},
+    macros::{buffer, command, metadata, r_println, renderer, routeify},
     metadata::Description,
 };
 
@@ -15,8 +15,10 @@ use crate::{
 #[derive(Debug, Default, Clone)]
 pub struct PkgShowEntry {
     pub name: String,
+
     /// Enabled version, from the content of the enable file.
     pub enabled: Option<String>,
+
     /// Installed versions, newest first.
     pub versions: Vec<String>,
 }
@@ -31,13 +33,14 @@ pub fn desc_pkg_show() -> Description {
     "Show locally installed packages".into()
 }
 
-pack_err!(ErrorNoPackagesInstalled);
+#[derive(Grouped, Default)]
+pub struct ErrorNoPackagesInstalled;
 
 #[command(node = "pkg-show", routeify)]
 pub fn package_show(packages_dir: &ResPackagesDir) -> Next {
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let mut entries: BTreeMap<String, PkgShowEntry> = BTreeMap::new();
@@ -84,7 +87,7 @@ pub fn package_show(packages_dir: &ResPackagesDir) -> Next {
     let packages: Vec<PkgShowEntry> = entries.into_values().collect();
 
     if packages.is_empty() {
-        return ErrorNoPackagesInstalled::default().into();
+        return ErrorNoPackagesInstalled.into();
     }
 
     ResultPkgShow { packages }.to_chain()
diff --git a/mingling_cli/src/pkg_mgr/cmd_uninstall.rs b/mingling_cli/src/pkg_mgr/cmd_uninstall.rs
index 2b288d6..0c3886c 100644
--- a/mingling_cli/src/pkg_mgr/cmd_uninstall.rs
+++ b/mingling_cli/src/pkg_mgr/cmd_uninstall.rs
@@ -1,8 +1,8 @@
 use std::{fs, io, path::PathBuf};
 
 use mingling::{
-    LazyRes, RenderResult, Routable, ShellContext, Suggest, SuggestItem,
-    macros::{arg, chain, command, completion, metadata, pack, pack_err, renderer, routeify},
+    Grouped, LazyRes, RenderResult, Routable, ShellContext, Suggest, SuggestItem, Wrap,
+    macros::{arg, chain, command, completion, metadata, renderer, routeify},
     metadata::Description,
     picker::{EntryPicker, PickerArg},
 };
@@ -20,16 +20,20 @@ use crate::{
 pub static ARG_PACKAGE: PickerArg<Option<String>> = arg![Option<String>];
 
 // Directory names to remove, e.g. `["omg@0.1.0", "omg@0.1.1"]`
-pack!(StateUninstallPackages = Vec<String>);
+#[derive(Grouped, Wrap)]
+pub struct StateUninstallPackages(Vec<String>);
 
 // Directories that were successfully removed.
-pack!(ResultPackageUninstalled = Vec<PathBuf>);
+#[derive(Grouped, Wrap)]
+pub struct ResultPackageUninstalled(Vec<PathBuf>);
 
 // Directories that were not installed.
-pack_err!(ErrorPackageNotInstall = Vec<PathBuf>);
+#[derive(Grouped, Wrap)]
+pub struct ErrorPackageNotInstall(Vec<PathBuf>);
 
 // No installed package matched the given spec.
-pack_err!(ErrorNoMatchingPackages);
+#[derive(Grouped, Default)]
+pub struct ErrorNoMatchingPackages;
 
 /// `{data_dir}/mingling/packages`
 #[metadata(EntryUninstall)]
@@ -46,7 +50,7 @@ pub fn uninstall(
     let spec = args.pick(&ARG_PACKAGE).to_result()?;
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let targets = match spec {
@@ -56,13 +60,13 @@ pub fn uninstall(
             let root_package = metadata
                 .root_package()
                 .or_else(|| metadata.workspace_packages().first().copied())
-                .ok_or(ErrorRootPackageNotFound::default())?;
+                .ok_or(ErrorRootPackageNotFound)?;
             vec![format!("{}@{}", root_package.name, root_package.version)]
         }
         // `name` matches every installed version, `name@version` matches exactly
         Some(spec) => {
             if spec.contains('/') || spec.contains('\\') || spec.contains("..") {
-                return ErrorPackageSpecInvalid::new(spec).to_chain();
+                return ErrorPackageSpecInvalid(spec).to_chain();
             }
             if spec.contains('@') {
                 vec![spec]
@@ -87,7 +91,7 @@ pub fn uninstall(
         }
     };
 
-    StateUninstallPackages::new(targets).to_chain()
+    StateUninstallPackages(targets).to_chain()
 }
 
 #[chain(routeify)]
@@ -97,13 +101,13 @@ pub fn handle_state_uninstall_packages(
 ) -> Next {
     let packages_dir = &packages_dir.path;
     if packages_dir.as_os_str().is_empty() {
-        return ErrorNoDataDirectory::default().to_chain();
+        return ErrorNoDataDirectory.to_chain();
     }
 
     let mut removed = Vec::new();
     let mut not_installed = Vec::new();
 
-    for name in p.inner {
+    for name in p.0 {
         let dir = packages_dir.join(&name);
         if !dir.exists() {
             not_installed.push(dir);
@@ -116,18 +120,18 @@ pub fn handle_state_uninstall_packages(
     }
 
     if removed.is_empty() && not_installed.is_empty() {
-        return ErrorNoMatchingPackages::default().to_chain();
+        return ErrorNoMatchingPackages.to_chain();
     }
     if !removed.is_empty() {
-        return ResultPackageUninstalled::new(removed).to_chain();
+        return ResultPackageUninstalled(removed).to_chain();
     }
-    ErrorPackageNotInstall::new(not_installed).to_chain()
+    ErrorPackageNotInstall(not_installed).to_chain()
 }
 
 #[renderer]
 pub fn render_result_package_uninstalled(r: ResultPackageUninstalled) -> RenderResult {
     let mut result = RenderResult::new();
-    for dir in r.inner {
+    for dir in r.0 {
         println_cargo!(result, "Uninstalled: {}", dir.display());
     }
     result
@@ -136,7 +140,7 @@ pub fn render_result_package_uninstalled(r: ResultPackageUninstalled) -> RenderR
 #[renderer]
 pub fn render_error_package_not_install(err: ErrorPackageNotInstall) -> RenderResult {
     let mut result = RenderResult::new();
-    for dir in err.info {
+    for dir in err.0 {
         eprintln_cargo!(result, "not installed: {}", dir.display());
     }
     result
diff --git a/mingling_cli/src/proj_mgr/cmd_class_add.rs b/mingling_cli/src/proj_mgr/cmd_class_add.rs
index 9c729a9..f9272a5 100644
--- a/mingling_cli/src/proj_mgr/cmd_class_add.rs
+++ b/mingling_cli/src/proj_mgr/cmd_class_add.rs
@@ -6,8 +6,8 @@ use std::{
 use just_fmt::{camel_case, kebab_case, pascal_case, snake_case};
 use just_template::Template;
 use mingling::{
-    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem,
-    macros::{arg, chain, command, completion, metadata, pack, pack_err, renderer, routeify},
+    Grouped, RenderResult, Routable, ShellContext, Suggest, SuggestItem, Wrap,
+    macros::{arg, chain, command, completion, metadata, renderer, routeify},
     metadata::Description,
     picker::EntryPicker,
     res::ResCurrentDir,
@@ -29,7 +29,8 @@ pub struct ClassEntry {
     pub description: String,
 }
 
-pack!(StateClassAdd = (String, String));
+#[derive(Grouped, Wrap)]
+pub struct StateClassAdd((String, String));
 
 /// Result of adding a class: the generated file path.
 #[derive(Debug, Default, Grouped)]
@@ -37,19 +38,28 @@ pub struct ResultClassAdd {
     pub output: PathBuf,
 }
 
-pack_err!(ErrorClassNameRequired = ());
-pack_err!(ErrorClassConfigMissing = String);
-pack_err!(ErrorClassNotFound = String);
-pack_err!(ErrorClassTemplateMissing = String);
-pack_err!(ErrorClassWriteFailed = String);
+#[derive(Grouped)]
+pub struct ErrorClassNameRequired;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorClassConfigMissing(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorClassNotFound(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorClassTemplateMissing(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorClassWriteFailed(String);
 
 #[command(node = "class-add", routeify)]
 pub fn class_add(args: EntryClassAdd) -> Next {
     let (class_name, name) = args
-        .pick_or_route(&arg![String], || ErrorClassNameRequired::new(()).to_chain())
-        .pick_or_route(&arg![String], || ErrorClassNameRequired::new(()).to_chain())
+        .pick_or_route(&arg![String], || ErrorClassNameRequired.to_chain())
+        .pick_or_route(&arg![String], || ErrorClassNameRequired.to_chain())
         .to_result()?;
-    StateClassAdd::new((class_name, name)).to_chain()
+    StateClassAdd((class_name, name)).to_chain()
 }
 
 /// Walk upward from `start` to find the first directory containing `.mling`.
@@ -91,11 +101,11 @@ fn deverbatim(path: &Path) -> PathBuf {
 /// name-derived parameters into `<output-dir>/<snake_case>.rs`.
 #[chain(routeify)]
 pub fn handle_state_class_add(state: StateClassAdd, cwd: &ResCurrentDir) -> Next {
-    let (class_name, name) = state.inner;
+    let (class_name, name) = state.0;
 
     // Resolve the project root: the nearest ancestor directory with `.mling`.
     let Some(project_root) = find_project_root(cwd) else {
-        return ErrorClassConfigMissing::new(format!(
+        return ErrorClassConfigMissing(format!(
             "no `.mling` directory found from {} upward; run this inside a mingling project",
             cwd.display()
         ))
@@ -105,14 +115,14 @@ pub fn handle_state_class_add(state: StateClassAdd, cwd: &ResCurrentDir) -> Next
     // Read `.mling/classes.toml` (the class registry).
     let classes_path = project_root.join(".mling").join("classes.toml");
     let content = fs::read_to_string(&classes_path).map_err(|e| {
-        ErrorClassConfigMissing::new(format!("failed to read {}: {e}", classes_path.display()))
+        ErrorClassConfigMissing(format!("failed to read {}: {e}", classes_path.display()))
     })?;
     let classes = parse_classes(&content)
-        .map_err(|e| ErrorClassConfigMissing::new(format!("invalid classes.toml: {e}")))?;
+        .map_err(|e| ErrorClassConfigMissing(format!("invalid classes.toml: {e}")))?;
 
     // Find the requested class type.
     let Some(entry) = classes.iter().find(|c| c.name == class_name) else {
-        return ErrorClassNotFound::new(format!(
+        return ErrorClassNotFound(format!(
             "class `{class_name}` not found in {}",
             classes_path.display()
         ))
@@ -122,7 +132,7 @@ pub fn handle_state_class_add(state: StateClassAdd, cwd: &ResCurrentDir) -> Next
     // Read the class template (relative to `.mling/`).
     let template_path = project_root.join(".mling").join(&entry.template);
     let template_content = fs::read_to_string(&template_path).map_err(|e| {
-        ErrorClassTemplateMissing::new(format!("failed to read {}: {e}", template_path.display()))
+        ErrorClassTemplateMissing(format!("failed to read {}: {e}", template_path.display()))
     })?;
 
     // Derive the name variants used by the template placeholders.
@@ -139,7 +149,7 @@ pub fn handle_state_class_add(state: StateClassAdd, cwd: &ResCurrentDir) -> Next
     tmpl.insert_param("upper_snake_case".to_string(), upper_snake);
     tmpl.insert_param("camel_case".to_string(), camel);
     let expanded = tmpl.expand().ok_or_else(|| {
-        ErrorClassWriteFailed::new(format!(
+        ErrorClassWriteFailed(format!(
             "failed to expand class template: {}",
             template_path.display()
         ))
@@ -149,11 +159,10 @@ pub fn handle_state_class_add(state: StateClassAdd, cwd: &ResCurrentDir) -> Next
     let output_dir = project_root.join(&entry.output_dir);
     let output = output_dir.join(format!("{snake}.rs"));
     fs::create_dir_all(&output_dir).map_err(|e| {
-        ErrorClassWriteFailed::new(format!("failed to create {}: {e}", output_dir.display()))
-    })?;
-    fs::write(&output, expanded).map_err(|e| {
-        ErrorClassWriteFailed::new(format!("failed to write {}: {e}", output.display()))
+        ErrorClassWriteFailed(format!("failed to create {}: {e}", output_dir.display()))
     })?;
+    fs::write(&output, expanded)
+        .map_err(|e| ErrorClassWriteFailed(format!("failed to write {}: {e}", output.display())))?;
 
     ResultClassAdd { output }.to_chain()
 }
@@ -215,28 +224,28 @@ pub fn render_error_class_name_required(_err: ErrorClassNameRequired) -> RenderR
 #[renderer]
 pub fn render_error_class_config_missing(err: ErrorClassConfigMissing) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_class_not_found(err: ErrorClassNotFound) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_class_template_missing(err: ErrorClassTemplateMissing) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_class_write_failed(err: ErrorClassWriteFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
diff --git a/mingling_cli/src/proj_mgr/cmd_proj_init.rs b/mingling_cli/src/proj_mgr/cmd_proj_init.rs
index 1ef8d1e..edad83c 100644
--- a/mingling_cli/src/proj_mgr/cmd_proj_init.rs
+++ b/mingling_cli/src/proj_mgr/cmd_proj_init.rs
@@ -7,8 +7,8 @@ use std::{
 use just_fmt::snake_case;
 use just_template::Template;
 use mingling::{
-    Grouped, LazyRes, RenderResult, Routable,
-    macros::{arg, chain, command, metadata, pack, pack_err, r_println, renderer, routeify},
+    Grouped, LazyRes, RenderResult, Routable, Wrap,
+    macros::{arg, chain, command, metadata, r_println, renderer, routeify},
     metadata::Description,
     picker::EntryPicker,
     res::ResCurrentDir,
@@ -30,8 +30,11 @@ const RULE_FILENAME: &str = "rule.toml";
 /// The directory under the project root where the template cache lives.
 const CACHE_DIR_NAME: &str = "tmpl-cache";
 
-pack!(StateProjectGenerate = ());
-pack!(StateProjectChecklistReady = Vec<String>);
+#[derive(Grouped)]
+pub struct StateProjectGenerate;
+
+#[derive(Grouped, Wrap)]
+pub struct StateProjectChecklistReady(Vec<String>);
 
 /// Result of the checklist phase: the extracted checklist handed to the user.
 #[derive(Debug, Default, Grouped)]
@@ -46,20 +49,31 @@ pub struct ResultProjectGenerate {
     pub hidden: Vec<PathBuf>,
 }
 
-pack_err!(ErrorTemplateNotProvided = ());
-pack_err!(ErrorTemplateCopyFailed = String);
-pack_err!(ErrorTemplateFetchFailed = String);
-pack_err!(ErrorChecklistMissing = String);
-pack_err!(ErrorRuleParseFailed = String);
-pack_err!(ErrorTemplateExpandFailed = String);
+#[derive(Grouped)]
+pub struct ErrorTemplateNotProvided;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorTemplateCopyFailed(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorTemplateFetchFailed(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorChecklistMissing(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorRuleParseFailed(String);
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorTemplateExpandFailed(String);
 
 #[command(node = "proj-init", routeify)]
 pub fn proj_init(args: Entry, cwd: &ResCurrentDir) -> Next {
     // Check if the checklist.toml file exists in the current directory
     if cwd.join(CHECKLIST_FILENAME).exists() {
-        StateProjectGenerate::new(()).into()
+        StateProjectGenerate.into()
     } else {
-        StateProjectChecklistReady::new(args.inner).into()
+        StateProjectChecklistReady(args.0).into()
     }
 }
 
@@ -73,7 +87,7 @@ pub fn handle_state_proj_checklist_ready(
 ) -> Next {
     let source: TemplateSource = args
         .pick_or_route(&arg![TemplateSource], || {
-            ErrorTemplateNotProvided::new(()).to_chain()
+            ErrorTemplateNotProvided.to_chain()
         })
         .to_result()?;
 
@@ -88,7 +102,7 @@ pub fn handle_state_proj_checklist_ready(
                 configured
             });
             resolve_git(&source_url, &reference, &variant, &cache_dir())
-                .map_err(ErrorTemplateFetchFailed::new)?
+                .map_err(ErrorTemplateFetchFailed)?
         }
     };
 
@@ -96,15 +110,15 @@ pub fn handle_state_proj_checklist_ready(
     // directory; create it if it doesn't exist
     let tmpl_cache = cwd.join(".mling").join(CACHE_DIR_NAME);
     fs::create_dir_all(&tmpl_cache).map_err(|e| {
-        ErrorTemplateCopyFailed::new(format!("failed to create {}: {e}", tmpl_cache.display()))
+        ErrorTemplateCopyFailed(format!("failed to create {}: {e}", tmpl_cache.display()))
     })?;
     copy_dir_contents(&template_root, &tmpl_cache)
-        .map_err(|e| ErrorTemplateCopyFailed::new(e.to_string()))?;
+        .map_err(|e| ErrorTemplateCopyFailed(e.to_string()))?;
 
     // Move the internal checklist.toml to ./ for the user to fill in
     let checklist_src = tmpl_cache.join(CHECKLIST_FILENAME);
     if !checklist_src.is_file() {
-        return ErrorChecklistMissing::new(format!(
+        return ErrorChecklistMissing(format!(
             "no checklist.toml found inside {}",
             template_root.display()
         ))
@@ -112,7 +126,7 @@ pub fn handle_state_proj_checklist_ready(
     }
     let checklist_dst = cwd.join(CHECKLIST_FILENAME);
     fs::rename(&checklist_src, &checklist_dst).map_err(|e| {
-        ErrorTemplateCopyFailed::new(format!(
+        ErrorTemplateCopyFailed(format!(
             "failed to move checklist.toml to {}: {e}",
             checklist_dst.display()
         ))
@@ -130,7 +144,7 @@ pub fn handle_state_proj_checklist_ready(
 pub fn handle_state_project_generate(_: StateProjectGenerate, cwd: &ResCurrentDir) -> Next {
     let tmpl_cache = cwd.join(".mling").join(CACHE_DIR_NAME);
     if !tmpl_cache.is_dir() {
-        return ErrorChecklistMissing::new(format!(
+        return ErrorChecklistMissing(format!(
             "template cache not found at {}; run `mling proj-init` with a template directory first",
             tmpl_cache.display()
         ))
@@ -140,22 +154,22 @@ pub fn handle_state_project_generate(_: StateProjectGenerate, cwd: &ResCurrentDi
     // Read the user-filled checklist.toml
     let checklist_path = cwd.join(CHECKLIST_FILENAME);
     let checklist_content = fs::read_to_string(&checklist_path).map_err(|e| {
-        ErrorChecklistMissing::new(format!("failed to read {}: {e}", checklist_path.display()))
+        ErrorChecklistMissing(format!("failed to read {}: {e}", checklist_path.display()))
     })?;
     let answers = parse_checklist(&checklist_content)
-        .map_err(|e| ErrorRuleParseFailed::new(format!("invalid checklist.toml: {e}")))?;
+        .map_err(|e| ErrorRuleParseFailed(format!("invalid checklist.toml: {e}")))?;
 
     // Read rule.toml (template rules)
     let rule_content = fs::read_to_string(tmpl_cache.join(RULE_FILENAME))
-        .map_err(|e| ErrorRuleParseFailed::new(format!("failed to read rule.toml: {e}")))?;
+        .map_err(|e| ErrorRuleParseFailed(format!("failed to read rule.toml: {e}")))?;
     let rules = parse_rules(&rule_content)
-        .map_err(|e| ErrorRuleParseFailed::new(format!("invalid rule.toml: {e}")))?;
+        .map_err(|e| ErrorRuleParseFailed(format!("invalid rule.toml: {e}")))?;
 
     // Compute final answers from checklist values + defaults declared in rule.toml
     let answers = resolve_answers(&answers, &rules);
 
     // Mutually exclusive toggle groups must not both be enabled.
-    validate_mutexes(&answers, &rules).map_err(ErrorRuleParseFailed::new)?;
+    validate_mutexes(&answers, &rules).map_err(ErrorRuleParseFailed)?;
 
     // Derive the crate name from the program name (e.g. `my-cli` -> `my_cli`).
     let mut params: HashMap<String, String> = answers.clone();
@@ -171,7 +185,7 @@ pub fn handle_state_project_generate(_: StateProjectGenerate, cwd: &ResCurrentDi
     // Expand all template entries to the project root
     let mut generated = Vec::new();
     expand_tree(&tmpl_cache, cwd, &params, &mut generated, true)
-        .map_err(ErrorTemplateExpandFailed::new)?;
+        .map_err(ErrorTemplateExpandFailed)?;
 
     // hide-file: delete the corresponding generated file when the rule is true
 
@@ -182,7 +196,7 @@ pub fn handle_state_project_generate(_: StateProjectGenerate, cwd: &ResCurrentDi
         }
         let target = cwd.join(hide.file.trim_start_matches("./"));
         remove_path(&target).map_err(|e| {
-            ErrorTemplateExpandFailed::new(format!("failed to hide {}: {e}", target.display()))
+            ErrorTemplateExpandFailed(format!("failed to hide {}: {e}", target.display()))
         })?;
         hidden.push(target);
     }
@@ -194,19 +208,19 @@ pub fn handle_state_project_generate(_: StateProjectGenerate, cwd: &ResCurrentDi
         }
         let target = cwd.join(hide.dir.trim_start_matches("./"));
         remove_path(&target).map_err(|e| {
-            ErrorTemplateExpandFailed::new(format!("failed to hide {}: {e}", target.display()))
+            ErrorTemplateExpandFailed(format!("failed to hide {}: {e}", target.display()))
         })?;
         hidden.push(target);
     }
 
     // Clean up the cache
     fs::remove_dir_all(&tmpl_cache).map_err(|e| {
-        ErrorTemplateExpandFailed::new(format!("failed to remove {}: {e}", tmpl_cache.display()))
+        ErrorTemplateExpandFailed(format!("failed to remove {}: {e}", tmpl_cache.display()))
     })?;
 
     // Project generated; remove the temporary checklist file
     remove_path(&checklist_path).map_err(|e| {
-        ErrorTemplateExpandFailed::new(format!(
+        ErrorTemplateExpandFailed(format!(
             "failed to remove {}: {e}",
             checklist_path.display()
         ))
@@ -327,35 +341,35 @@ pub fn render_error_template_not_provided(_err: ErrorTemplateNotProvided) -> Ren
 #[renderer]
 pub fn render_error_template_copy_failed(err: ErrorTemplateCopyFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "failed to copy template: {}", err.info);
+    eprintln_cargo!(r, "failed to copy template: {}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_template_fetch_failed(err: ErrorTemplateFetchFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "failed to fetch template: {}", err.info);
+    eprintln_cargo!(r, "failed to fetch template: {}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_checklist_missing(err: ErrorChecklistMissing) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_rule_parse_failed(err: ErrorRuleParseFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
 #[renderer]
 pub fn render_error_template_expand_failed(err: ErrorTemplateExpandFailed) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "{}", err.info);
+    eprintln_cargo!(r, "{}", err.0);
     r
 }
 
diff --git a/mingling_macros/src/attr/dispatcher_clap.rs b/mingling_macros/src/attr/dispatcher_clap.rs
index 46238d6..c2dd952 100644
--- a/mingling_macros/src/attr/dispatcher_clap.rs
+++ b/mingling_macros/src/attr/dispatcher_clap.rs
@@ -133,7 +133,7 @@ pub(crate) fn dispatcher_clap_attr(attr: TokenStream, item: TokenStream) -> Toke
                 match <#struct_name as ::clap::Parser>::try_parse_from(clap_args) {
                     Ok(parsed) => ::mingling::Routable::<#program_path>::to_chain(parsed),
                     Err(e) => {
-                        return ::mingling::Routable::<#program_path>::to_render(#error_struct::new(format!("{}", e.render().ansi())))
+                        return ::mingling::Routable::<#program_path>::to_render(#error_struct(format!("{}", e.render().ansi())))
                     },
                 }
             }
@@ -143,7 +143,8 @@ pub(crate) fn dispatcher_clap_attr(attr: TokenStream, item: TokenStream) -> Toke
     // Generate the error pack type
     let error_pack = options.error_struct.as_ref().map(|error_struct| {
         quote! {
-            ::mingling::macros::pack!(#error_struct = String);
+            #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+            pub struct #error_struct(pub ::std::string::String);
         }
     });
 
@@ -188,7 +189,7 @@ pub(crate) fn dispatcher_clap_attr(attr: TokenStream, item: TokenStream) -> Toke
         // Keep the original struct definition
         #input_struct
 
-        // Generate the error wrapper type via pack!
+        // Generate the error wrapper type
         #error_pack
 
         // Generate the help block if enabled
diff --git a/mingling_macros/src/func.rs b/mingling_macros/src/func.rs
index 57d0ec5..baa23db 100644
--- a/mingling_macros/src/func.rs
+++ b/mingling_macros/src/func.rs
@@ -9,13 +9,6 @@ pub(crate) mod gen_program;
 pub(crate) mod group;
 #[cfg(all(feature = "structural_renderer", feature = "extras"))]
 pub(crate) mod group_structural;
-pub(crate) mod pack;
-#[cfg(feature = "extras")]
-pub(crate) mod pack_err;
-#[cfg(all(feature = "structural_renderer", feature = "extras"))]
-pub(crate) mod pack_err_structural;
-#[cfg(feature = "structural_renderer")]
-pub(crate) mod pack_structural;
 #[cfg(feature = "comp")]
 pub(crate) mod program_comp_gen;
 pub(crate) mod program_fallback_gen;
diff --git a/mingling_macros/src/func/dispatcher.rs b/mingling_macros/src/func/dispatcher.rs
index c4d67a9..41dd2d0 100644
--- a/mingling_macros/src/func/dispatcher.rs
+++ b/mingling_macros/src/func/dispatcher.rs
@@ -115,7 +115,9 @@ pub(crate) fn dispatcher(input: TokenStream) -> TokenStream {
     let program_type = crate::default_program_path();
 
     let expanded = quote! {
-        ::mingling::macros::pack!(#(#entry_attrs)* #pack = Vec<String>);
+        #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+        #(#entry_attrs)*
+        pub struct #pack(pub ::std::vec::Vec<::std::string::String>);
 
         #(#cmd_attrs)*
         #[doc(hidden)]
@@ -127,7 +129,7 @@ pub(crate) fn dispatcher(input: TokenStream) -> TokenStream {
 
         impl From<#pack> for crate::Entry {
             fn from(value: #pack) -> Self {
-                crate::Entry::new(value.inner)
+                crate::Entry(value.0)
             }
         }
 
@@ -136,7 +138,7 @@ pub(crate) fn dispatcher(input: TokenStream) -> TokenStream {
         impl ::mingling::Dispatcher<#program_type> for #hidden_dispatcher {
             fn begin(&self, args: Vec<String>) -> ::mingling::ChainProcess<#program_type> {
                 use ::mingling::Grouped;
-                ::mingling::Routable::to_chain(#pack::new(args))
+                ::mingling::Routable::to_chain(#pack(args))
             }
         }
     };
@@ -149,7 +151,7 @@ fn get_comp_entry(entry_name: &Ident) -> TokenStream2 {
     let comp_entry = quote! {
         impl ::mingling::CompletionEntry for #entry_name {
             fn get_input(self) -> Vec<String> {
-                self.inner.clone()
+                self.0.clone()
             }
         }
     };
diff --git a/mingling_macros/src/func/entry.rs b/mingling_macros/src/func/entry.rs
index 82dfd3e..18e485f 100644
--- a/mingling_macros/src/func/entry.rs
+++ b/mingling_macros/src/func/entry.rs
@@ -57,7 +57,7 @@ pub(crate) fn entry(input: TokenStream) -> TokenStream {
     let expanded = match parsed {
         EntryInput::Typed { ident, .. } => {
             quote! {
-                #ident::new(vec![#(#string_exprs),*])
+                #ident(vec![#(#string_exprs),*])
             }
         }
         EntryInput::Untyped { .. } => {
diff --git a/mingling_macros/src/func/gen_program.rs b/mingling_macros/src/func/gen_program.rs
index a53f86f..c0a7ea8 100644
--- a/mingling_macros/src/func/gen_program.rs
+++ b/mingling_macros/src/func/gen_program.rs
@@ -57,7 +57,8 @@ pub(crate) fn gen_program_impl(_input: TokenStream) -> TokenStream {
             /// Alias for the current program type `ThisProgram`
             pub type Next = ::mingling::ChainProcess<ThisProgram>;
 
-            ::mingling::macros::pack!(Entry = Vec<String>);
+            #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+            pub struct Entry(pub ::std::vec::Vec<::std::string::String>);
 
             impl ::mingling::Routable<ThisProgram> for ::mingling::ChainProcess<ThisProgram>
             {
diff --git a/mingling_macros/src/func/pack.rs b/mingling_macros/src/func/pack.rs
deleted file mode 100644
index d4fcb60..0000000
--- a/mingling_macros/src/func/pack.rs
+++ /dev/null
@@ -1,154 +0,0 @@
-// Doc Not Optimize
-use proc_macro::TokenStream;
-use quote::quote;
-use syn::parse::{Parse, ParseStream};
-use syn::{Attribute, Ident, Result as SynResult, Token, Type};
-
-struct PackInput {
-    attrs: Vec<Attribute>,
-    type_name: Ident,
-    inner_type: Type,
-}
-
-impl Parse for PackInput {
-    fn parse(input: ParseStream) -> SynResult<Self> {
-        let attrs = input.call(Attribute::parse_outer)?;
-        let type_name: Ident = input.parse()?;
-        input.parse::<Token![=]>()?;
-        let inner_type: Type = input.parse()?;
-
-        Ok(Self {
-            attrs,
-            type_name,
-            inner_type,
-        })
-    }
-}
-
-#[allow(clippy::too_many_lines)]
-pub(crate) fn pack(input: TokenStream) -> TokenStream {
-    let pack_input = syn::parse_macro_input!(input as PackInput);
-
-    let group_name = crate::default_program_path();
-    let type_name = pack_input.type_name;
-    let inner_type = pack_input.inner_type;
-    let attrs = pack_input.attrs;
-
-    // Generate the struct definition
-    // Note: No longer derives Serialize under structural_renderer.
-    // Use pack_structual! for structured output support.
-    let struct_def = quote! {
-        #(#attrs)*
-        pub struct #type_name {
-            pub(crate) inner: #inner_type,
-        }
-    };
-
-    // Generate the new() method
-    let new_impl = quote! {
-        impl #type_name {
-            /// Creates a new instance of the wrapper type
-            pub fn new(inner: #inner_type) -> Self {
-                Self { inner }
-            }
-        }
-    };
-
-    // Generate From and Into implementations
-    let from_into_impl = quote! {
-        impl From<#inner_type> for #type_name {
-            fn from(inner: #inner_type) -> Self {
-                Self::new(inner)
-            }
-        }
-
-        impl From<#type_name> for #inner_type {
-            fn from(wrapper: #type_name) -> #inner_type {
-                wrapper.inner
-            }
-        }
-    };
-
-    // Generate AsRef and AsMut implementations
-    let as_ref_impl = quote! {
-        impl ::std::convert::AsRef<#inner_type> for #type_name {
-            fn as_ref(&self) -> &#inner_type {
-                &self.inner
-            }
-        }
-
-        impl ::std::convert::AsMut<#inner_type> for #type_name {
-            fn as_mut(&mut self) -> &mut #inner_type {
-                &mut self.inner
-            }
-        }
-    };
-
-    // Generate Deref and DerefMut implementations
-    let deref_impl = quote! {
-        impl ::std::ops::Deref for #type_name {
-            type Target = #inner_type;
-
-            fn deref(&self) -> &Self::Target {
-                &self.inner
-            }
-        }
-
-        impl ::std::ops::DerefMut for #type_name {
-            fn deref_mut(&mut self) -> &mut Self::Target {
-                &mut self.inner
-            }
-        }
-    };
-
-    // Check if the inner type implements Default by generating conditional code
-    let default_impl = quote! {
-        impl ::std::default::Default for #type_name
-        where
-            #inner_type: ::std::default::Default,
-        {
-            fn default() -> Self {
-                Self::new(::std::default::Default::default())
-            }
-        }
-    };
-
-    let register_impl = quote! {
-        ::mingling::macros::register_type!(#type_name);
-    };
-
-    let expanded = quote! {
-        #struct_def
-
-        #new_impl
-        #from_into_impl
-        #as_ref_impl
-        #deref_impl
-        #default_impl
-        #register_impl
-
-        impl Into<mingling::AnyOutput<#group_name>> for #type_name {
-            fn into(self) -> mingling::AnyOutput<#group_name> {
-                mingling::AnyOutput::new(self)
-            }
-        }
-
-        impl Into<mingling::ChainProcess<#group_name>> for #type_name {
-            fn into(self) -> mingling::ChainProcess<#group_name> {
-                mingling::AnyOutput::new(self).route_chain()
-            }
-        }
-
-        /// SAFETY: This is an internal implementation of the `pack!` macro,
-        /// guaranteeing that the enum value registered by the `register_type!` macro
-        /// is exactly the same as the actual return value,
-        /// which can be confirmed via the `Ident` in the `quote!` block.
-        unsafe impl ::mingling::Grouped<#group_name> for #type_name {
-            fn member_id() -> #group_name {
-                #group_name::#type_name
-            }
-        }
-    };
-
-    expanded.into()
-}
diff --git a/mingling_macros/src/func/pack_err.rs b/mingling_macros/src/func/pack_err.rs
deleted file mode 100644
index e925b82..0000000
--- a/mingling_macros/src/func/pack_err.rs
+++ /dev/null
@@ -1,108 +0,0 @@
-// Doc Not Optimize
-use just_fmt::snake_case;
-use proc_macro::TokenStream;
-use quote::quote;
-use syn::{Ident, Token, Type, parse_macro_input};
-
-enum PackErrInput {
-    /// `pack_err!(ErrorNotFound)`
-    Simple { type_name: Ident },
-    /// `pack_err!(ErrorNotDir = PathBuf)`
-    Typed {
-        type_name: Ident,
-        inner_type: Box<Type>,
-    },
-}
-
-impl syn::parse::Parse for PackErrInput {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-        let type_name: Ident = input.parse()?;
-
-        if input.peek(Token![=]) {
-            input.parse::<Token![=]>()?;
-            let inner_type: Type = input.parse()?;
-            Ok(Self::Typed {
-                type_name,
-                inner_type: Box::new(inner_type),
-            })
-        } else {
-            Ok(Self::Simple { type_name })
-        }
-    }
-}
-
-#[allow(clippy::too_many_lines)]
-pub(crate) fn pack_err(input: TokenStream) -> TokenStream {
-    let parsed = parse_macro_input!(input as PackErrInput);
-
-    match parsed {
-        PackErrInput::Simple { type_name } => {
-            let name_str = type_name.to_string();
-            let snake_name = snake_case!(&name_str);
-
-            // Note: No longer derives Serialize under structural_renderer.
-            // Use pack_err_structural for structured output support.
-            let derive = quote! {
-                #[derive(::mingling::Grouped)]
-            };
-
-            let expanded = quote! {
-                #derive
-                pub struct #type_name {
-                    /// The snake_case name of this error, automatically set at compile time.
-                    pub name: String,
-                }
-
-                impl ::std::default::Default for #type_name {
-                    fn default() -> Self {
-                        Self {
-                            name: #snake_name.into(),
-                        }
-                    }
-                }
-
-                ::mingling::macros::register_type!(#type_name);
-            };
-
-            expanded.into()
-        }
-        PackErrInput::Typed {
-            type_name,
-            inner_type,
-        } => {
-            let name_str = type_name.to_string();
-            let snake_name = snake_case!(&name_str);
-
-            // Note: No longer derives Serialize under structural_renderer.
-            // Use pack_err_structural for structured output support.
-            let derive = quote! {
-                #[derive(::mingling::Grouped)]
-            };
-
-            let expanded = quote! {
-                #derive
-                pub struct #type_name {
-                    /// The snake_case name of this error, automatically set at compile time.
-                    pub name: String,
-                    /// Additional context info for this error.
-                    pub info: #inner_type,
-                }
-
-                impl #type_name {
-                    /// Creates a new error with the given info.
-                    /// The `name` field is automatically set to the snake_case of the struct name.
-                    pub fn new(info: #inner_type) -> Self {
-                        Self {
-                            name: #snake_name.into(),
-                            info,
-                        }
-                    }
-                }
-
-                ::mingling::macros::register_type!(#type_name);
-            };
-
-            expanded.into()
-        }
-    }
-}
diff --git a/mingling_macros/src/func/pack_err_structural.rs b/mingling_macros/src/func/pack_err_structural.rs
deleted file mode 100644
index 950b8dc..0000000
--- a/mingling_macros/src/func/pack_err_structural.rs
+++ /dev/null
@@ -1,121 +0,0 @@
-// Doc Not Optimize
-use just_fmt::snake_case;
-use proc_macro::TokenStream;
-use quote::quote;
-use syn::{Ident, Token, Type, parse_macro_input};
-
-/// `pack_err_structural!` — like `pack_err!` but also marks the type as
-/// supporting structured output via `StructuralData`.
-pub(crate) fn pack_err_structural(input: TokenStream) -> TokenStream {
-    let parsed = parse_macro_input!(input as PackErrInput);
-
-    let type_name = match &parsed {
-        PackErrInput::Simple { type_name } | PackErrInput::Typed { type_name, .. } => {
-            type_name.clone()
-        }
-    };
-
-    // Register in STRUCTURED_TYPES
-    let type_name_str = type_name.to_string();
-    crate::get_global_set(&crate::STRUCTURED_TYPES)
-        .lock()
-        .unwrap()
-        .insert(type_name_str);
-
-    let structural_data = quote! {
-        impl ::mingling::__private::StructuralDataSealed<crate::ThisProgram> for #type_name {}
-        impl ::mingling::__private::StructuralData<crate::ThisProgram> for #type_name {}
-    };
-
-    // Generate the struct + impls (same as pack_err! but with Serialize derive + sealed)
-    match parsed {
-        PackErrInput::Simple { type_name } => {
-            let name_str = type_name.to_string();
-            let snake_name = snake_case!(&name_str);
-
-            let expanded = quote! {
-                #[derive(::mingling::Grouped, ::serde::Serialize)]
-                pub struct #type_name {
-                    /// The snake_case name of this error, automatically set at compile time.
-                    pub name: String,
-                }
-
-                impl ::std::default::Default for #type_name {
-                    fn default() -> Self {
-                        Self {
-                            name: #snake_name.into(),
-                        }
-                    }
-                }
-
-                ::mingling::macros::register_type!(#type_name);
-
-                #structural_data
-            };
-
-            expanded.into()
-        }
-        PackErrInput::Typed {
-            type_name,
-            inner_type,
-        } => {
-            let name_str = type_name.to_string();
-            let snake_name = snake_case!(&name_str);
-
-            let expanded = quote! {
-                #[derive(::mingling::Grouped, ::serde::Serialize)]
-                pub struct #type_name {
-                    /// The snake_case name of this error, automatically set at compile time.
-                    pub name: String,
-                    /// Additional context info for this error.
-                    pub info: #inner_type,
-                }
-
-                impl #type_name {
-                    /// Creates a new error with the given info.
-                    /// The `name` field is automatically set to the snake_case of the struct name.
-                    pub fn new(info: #inner_type) -> Self {
-                        Self {
-                            name: #snake_name.into(),
-                            info,
-                        }
-                    }
-                }
-
-                ::mingling::macros::register_type!(#type_name);
-
-                #structural_data
-            };
-
-            expanded.into()
-        }
-    }
-}
-
-// Re-use pack_err's input parser
-enum PackErrInput {
-    Simple {
-        type_name: Ident,
-    },
-    Typed {
-        type_name: Ident,
-        inner_type: Box<Type>,
-    },
-}
-
-impl syn::parse::Parse for PackErrInput {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-        let type_name: Ident = input.parse()?;
-
-        if input.peek(Token![=]) {
-            input.parse::<Token![=]>()?;
-            let inner_type: Type = input.parse()?;
-            Ok(Self::Typed {
-                type_name,
-                inner_type: Box::new(inner_type),
-            })
-        } else {
-            Ok(Self::Simple { type_name })
-        }
-    }
-}
diff --git a/mingling_macros/src/func/pack_structural.rs b/mingling_macros/src/func/pack_structural.rs
deleted file mode 100644
index fb13fbf..0000000
--- a/mingling_macros/src/func/pack_structural.rs
+++ /dev/null
@@ -1,170 +0,0 @@
-// Doc Not Optimize
-use proc_macro::TokenStream;
-use quote::quote;
-use syn::Ident;
-
-use crate::get_global_set;
-
-/// `pack_structural!` — like `pack!` but also marks the type as supporting
-/// structured output via `StructuralData`.
-#[allow(clippy::too_many_lines)]
-pub(crate) fn pack_structural(input: TokenStream) -> TokenStream {
-    // Parse same input format as `pack!`
-    let input_parsed = syn::parse_macro_input!(input as PackStructuralInput);
-    let type_name = input_parsed.type_name;
-    let inner_type = input_parsed.inner_type;
-    let attrs = input_parsed.attrs;
-    let program_path = crate::default_program_path();
-
-    // Register in STRUCTURED_TYPES
-    let type_name_str = type_name.to_string();
-    get_global_set(&crate::STRUCTURED_TYPES)
-        .lock()
-        .unwrap()
-        .insert(type_name_str);
-
-    // Struct definition (with Serialize derive, same as pack! under structural_renderer)
-    #[cfg(not(feature = "structural_renderer"))]
-    let struct_def = quote! {
-        #(#attrs)*
-        pub struct #type_name {
-            pub inner: #inner_type,
-        }
-    };
-
-    #[cfg(feature = "structural_renderer")]
-    let struct_def = quote! {
-        #(#attrs)*
-        #[derive(serde::Serialize)]
-        pub struct #type_name {
-            pub inner: #inner_type,
-        }
-    };
-
-    // Helper impls (same as pack!)
-    let new_impl = quote! {
-        impl #type_name {
-            pub fn new(inner: #inner_type) -> Self {
-                Self { inner }
-            }
-        }
-    };
-
-    let from_into_impl = quote! {
-        impl From<#inner_type> for #type_name {
-            fn from(inner: #inner_type) -> Self {
-                Self::new(inner)
-            }
-        }
-        impl From<#type_name> for #inner_type {
-            fn from(wrapper: #type_name) -> #inner_type {
-                wrapper.inner
-            }
-        }
-    };
-
-    let as_ref_impl = quote! {
-        impl ::std::convert::AsRef<#inner_type> for #type_name {
-            fn as_ref(&self) -> &#inner_type {
-                &self.inner
-            }
-        }
-        impl ::std::convert::AsMut<#inner_type> for #type_name {
-            fn as_mut(&mut self) -> &mut #inner_type {
-                &mut self.inner
-            }
-        }
-    };
-
-    let deref_impl = quote! {
-        impl ::std::ops::Deref for #type_name {
-            type Target = #inner_type;
-            fn deref(&self) -> &Self::Target {
-                &self.inner
-            }
-        }
-        impl ::std::ops::DerefMut for #type_name {
-            fn deref_mut(&mut self) -> &mut Self::Target {
-                &mut self.inner
-            }
-        }
-    };
-
-    let default_impl = quote! {
-        impl ::std::default::Default for #type_name
-        where
-            #inner_type: ::std::default::Default,
-        {
-            fn default() -> Self {
-                Self::new(::std::default::Default::default())
-            }
-        }
-    };
-
-    let register_impl = quote! {
-        ::mingling::macros::register_type!(#type_name);
-    };
-
-    // StructuralData impl + sealed + registration
-    let structural_impl = quote! {
-        impl ::mingling::__private::StructuralDataSealed<crate::ThisProgram> for #type_name {}
-        impl ::mingling::__private::StructuralData<crate::ThisProgram> for #type_name {}
-    };
-
-    let expanded = quote! {
-        #struct_def
-
-        #new_impl
-        #from_into_impl
-        #as_ref_impl
-        #deref_impl
-        #default_impl
-        #register_impl
-        #structural_impl
-
-        impl Into<::mingling::AnyOutput<#program_path>> for #type_name {
-            fn into(self) -> ::mingling::AnyOutput<#program_path> {
-                ::mingling::AnyOutput::new(self)
-            }
-        }
-
-        impl Into<::mingling::ChainProcess<#program_path>> for #type_name {
-            fn into(self) -> ::mingling::ChainProcess<#program_path> {
-                ::mingling::AnyOutput::new(self).route_chain()
-            }
-        }
-
-        /// SAFETY: This is an internal implementation of the `pack_structural!` macro,
-        /// guaranteeing that the enum value registered by the `register_type!` macro
-        /// is exactly the same as the actual return value,
-        /// which can be confirmed via the `Ident` in the `quote!` block.
-        unsafe impl ::mingling::Grouped<#program_path> for #type_name {
-            fn member_id() -> #program_path {
-                #program_path::#type_name
-            }
-        }
-    };
-
-    expanded.into()
-}
-
-/// Input for `pack_structural!` — same format as `pack!`.
-struct PackStructuralInput {
-    attrs: Vec<syn::Attribute>,
-    type_name: Ident,
-    inner_type: syn::Type,
-}
-
-impl syn::parse::Parse for PackStructuralInput {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-        let attrs = input.call(syn::Attribute::parse_outer)?;
-        let type_name: Ident = input.parse()?;
-        input.parse::<syn::Token![=]>()?;
-        let inner_type: syn::Type = input.parse()?;
-        Ok(Self {
-            attrs,
-            type_name,
-            inner_type,
-        })
-    }
-}
diff --git a/mingling_macros/src/func/program_comp_gen.rs b/mingling_macros/src/func/program_comp_gen.rs
index ed04379..cdd2597 100644
--- a/mingling_macros/src/func/program_comp_gen.rs
+++ b/mingling_macros/src/func/program_comp_gen.rs
@@ -11,11 +11,11 @@ pub(crate) fn program_comp_gen_impl(_input: TokenStream) -> TokenStream {
         pub async fn __exec_completion(prev: CompletionContext) -> Next {
             use ::mingling::Grouped;
 
-            let read_ctx = ::mingling::ShellContext::try_from(prev.inner);
+            let read_ctx = ::mingling::ShellContext::try_from(prev.0);
             match read_ctx {
                 Ok(ctx) => {
                     let suggest = ::mingling::CompletionHelper::exec_completion::<crate::ThisProgram>(&ctx);
-                    ::mingling::Routable::<crate::ThisProgram>::to_render(CompletionSuggest::new((ctx, suggest)))
+                    ::mingling::Routable::<crate::ThisProgram>::to_render(CompletionSuggest((ctx, suggest)))
                 }
                 Err(_) => std::process::exit(1),
             }
@@ -29,11 +29,11 @@ pub(crate) fn program_comp_gen_impl(_input: TokenStream) -> TokenStream {
         pub fn __exec_completion(prev: CompletionContext) -> Next {
             use ::mingling::Grouped;
 
-            let read_ctx = ::mingling::ShellContext::try_from(prev.inner);
+            let read_ctx = ::mingling::ShellContext::try_from(prev.0);
             match read_ctx {
                 Ok(ctx) => {
                     let suggest = ::mingling::CompletionHelper::exec_completion::<crate::ThisProgram>(&ctx);
-                    ::mingling::Routable::<crate::ThisProgram>::to_render(CompletionSuggest::new((ctx, suggest)))
+                    ::mingling::Routable::<crate::ThisProgram>::to_render(CompletionSuggest((ctx, suggest)))
                 }
                 Err(_) => std::process::exit(1),
             }
@@ -50,9 +50,8 @@ pub(crate) fn program_comp_gen_impl(_input: TokenStream) -> TokenStream {
         mod __internal_completion_mod {
             use ::mingling::Grouped;
             ::mingling::macros::dispatcher!("__comp", CompletionContext);
-            ::mingling::macros::pack!(
-                CompletionSuggest = (::mingling::ShellContext, ::mingling::Suggest)
-            );
+            #[derive(::mingling::Grouped, ::mingling::Wrap)]
+            pub struct CompletionSuggest(pub (::mingling::ShellContext, ::mingling::Suggest));
         }
         #internal_dispatcher_comp
         use __internal_completion_mod::CompletionContext;
@@ -67,7 +66,7 @@ pub(crate) fn program_comp_gen_impl(_input: TokenStream) -> TokenStream {
         #[::mingling::macros::renderer]
         pub fn __render_completion(prev: CompletionSuggest) -> ::mingling::RenderResult {
             let result = ::mingling::RenderResult::default();
-            let (ctx, suggest) = prev.inner;
+            let (ctx, suggest) = prev.0;
             ::mingling::CompletionHelper::render_suggest::<crate::ThisProgram>(&ctx, suggest);
             result
         }
diff --git a/mingling_macros/src/func/program_fallback_gen.rs b/mingling_macros/src/func/program_fallback_gen.rs
index df53c60..1f3fdce 100644
--- a/mingling_macros/src/func/program_fallback_gen.rs
+++ b/mingling_macros/src/func/program_fallback_gen.rs
@@ -16,8 +16,12 @@ pub(crate) fn program_fallback_gen_impl(_input: TokenStream) -> TokenStream {
     };
 
     let expanded = quote! {
-        ::mingling::macros::pack!(ErrorRendererNotFound = String);
-        ::mingling::macros::pack!(EntryFallback = Vec<String>);
+        #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+        pub struct ErrorRendererNotFound(pub ::std::string::String);
+
+        #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+        pub struct EntryFallback(pub ::std::vec::Vec<::std::string::String>);
+
         #pack_empty
     };
     TokenStream::from(expanded)
diff --git a/mingling_macros/src/func/program_final_gen.rs b/mingling_macros/src/func/program_final_gen.rs
index d549a2b..8123eaf 100644
--- a/mingling_macros/src/func/program_final_gen.rs
+++ b/mingling_macros/src/func/program_final_gen.rs
@@ -376,10 +376,10 @@ pub(crate) fn program_final_gen_impl(_input: TokenStream) -> TokenStream {
             type ResultEmpty = ResultEmpty;
 
             fn build_renderer_not_found(member_id: Self::Enum) -> ::mingling::AnyOutput<Self::Enum> {
-                ::mingling::AnyOutput::new(ErrorRendererNotFound::new(member_id.to_string()))
+                ::mingling::AnyOutput::new(ErrorRendererNotFound(member_id.to_string()))
             }
             fn build_entry_fallback(args: Vec<String>) -> ::mingling::AnyOutput<Self::Enum> {
-                ::mingling::AnyOutput::new(EntryFallback::new(args))
+                ::mingling::AnyOutput::new(EntryFallback(args))
             }
             fn build_empty_result() -> ::mingling::AnyOutput<Self::Enum> {
                 ::mingling::AnyOutput::new(ResultEmpty)
diff --git a/mingling_macros/src/lib.rs b/mingling_macros/src/lib.rs
index 7da7db3..d0556dc 100644
--- a/mingling_macros/src/lib.rs
+++ b/mingling_macros/src/lib.rs
@@ -34,15 +34,13 @@ use attr::dispatcher_clap;
 use attr::program_setup;
 use attr::{chain, help, metadata, renderer};
 use derive::{enum_tag, grouped, wrap};
+use func::dispatcher;
 #[cfg(feature = "extras")]
 use func::entry;
 #[cfg(feature = "extras")]
 pub(crate) use func::group as group_impl;
-#[cfg(feature = "extras")]
-use func::pack_err;
 #[cfg(feature = "comp")]
 use func::suggest;
-use func::{dispatcher, pack};
 use systems::res_injection;
 pub(crate) fn default_program_path() -> proc_macro2::TokenStream {
     quote::quote! { crate::ThisProgram }
@@ -60,7 +58,7 @@ pub(crate) type Registry = OnceLock<Mutex<BTreeSet<String>>>;
 pub(crate) static STRUCTURAL_RENDERERS: Registry = OnceLock::new();
 
 /// Types explicitly marked with `#[derive(StructuralData)]` or created via
-/// `pack_structural!` / `group_structural!`.
+/// `group_structural!`.
 #[cfg(feature = "structural_renderer")]
 pub(crate) static STRUCTURED_TYPES: Registry = OnceLock::new();
 
@@ -183,163 +181,6 @@ pub fn group_structural(input: TokenStream) -> TokenStream {
     func::group_structural::group_structural(input)
 }
 
-/// Creates a type-safe wrapper struct around an inner type, with automatic
-/// trait implementations for use in the Mingling chain/render pipeline.
-///
-/// The generated struct implements: `From`/`Into`, `AsRef`/`AsMut`, `Deref`/`DerefMut`,
-/// `Default` (conditional on inner type), and conversion into `AnyOutput` /
-/// `ChainProcess` for routing.
-///
-/// # Syntax
-///
-/// ```rust,ignore
-/// // Default program name (uses `ThisProgram`):
-/// pack!(TypeName = InnerType);
-///
-/// // Explicit program name:
-/// pack!(MyProgram, TypeName = InnerType);
-/// ```
-///
-/// # Example
-///
-/// ```rust,ignore
-/// use mingling::macros::pack;
-///
-/// // Creates `Hello` wrapping `String`, registered under `ThisProgram`:
-/// pack!(Hello = String);
-///
-/// // Creates `Greeting` wrapping `String`, registered under `MyApp`:
-/// pack!(MyApp, Greeting = String);
-/// ```
-///
-/// After expansion, `Hello` has:
-/// - `Hello::new(String)` — constructor
-/// - `Hello::to_chain()` — routes to the next chain processor
-/// - `Hello::to_render()` — routes to a renderer
-/// - `From<String> for Hello`, `From<Hello> for String`
-/// - `Deref<Target = String>`, `DerefMut`
-/// - `AsRef<String>`, `AsMut<String>`
-/// - `Default` if `String: Default`
-/// - `Into<AnyOutput<ThisProgram>>`, `Into<ChainProcess<ThisProgram>>`
-/// - Implements `Grouped<ThisProgram>` with `member_id()` returning the enum variant
-///
-/// The struct is also registered via `register_type!` so that `gen_program!`
-/// can include it in the program enum.
-///
-/// When the `structural_renderer` feature is enabled, the struct also gets
-/// `#[derive(serde::Serialize)]`.
-#[proc_macro]
-pub fn pack(input: TokenStream) -> TokenStream {
-    pack::pack(input)
-}
-
-/// Like `pack!` but also marks the type as supporting structured output
-/// (JSON / YAML / TOML / RON) via `StructuralData`.
-///
-/// # Syntax
-///
-/// ```rust,ignore
-/// pack_structural!(Info = (String, i32));
-/// ```
-///
-/// This is equivalent to:
-/// ```rust,ignore
-/// pack!(Info = (String, i32));
-/// impl ::mingling::StructuralData for Info {}
-/// ```
-///
-/// Requires the `structural_renderer` feature.
-#[cfg(feature = "structural_renderer")]
-#[proc_macro]
-pub fn pack_structural(input: TokenStream) -> TokenStream {
-    func::pack_structural::pack_structural(input)
-}
-
-/// Creates an error struct with a `name: String` field and optional `info: Type` field.
-///
-/// This macro provides a concise way to define error types that implement `Grouped`
-/// and are registered for inclusion in the program enum.
-///
-/// The `name` field is automatically set to the `snake_case` version of the struct name
-/// at compile time.
-///
-/// # Syntax
-///
-/// Two forms are supported:
-///
-/// ```rust,ignore
-/// // Simple form — generates a struct with only `name: String` and a `Default` impl:
-/// pack_err!(ErrorNotFound);
-///
-/// // Typed form — generates a struct with `name: String` + `info: Type` and a `new(info)` constructor:
-/// pack_err!(ErrorNotDir = PathBuf);
-/// ```
-///
-/// # Generated code
-///
-/// For `pack_err!(ErrorNotFound)`:
-///
-/// ```rust,ignore
-/// #[derive(::mingling::Grouped)]
-/// pub struct ErrorNotFound {
-///     name: String,
-/// }
-///
-/// impl Default for ErrorNotFound {
-///     fn default() -> Self {
-///         Self {
-///             name: "error_not_found".into(),
-///         }
-///     }
-/// }
-/// ```
-///
-/// For `pack_err!(ErrorNotDir = PathBuf)`:
-///
-/// ```rust,ignore
-/// #[derive(::mingling::Grouped)]
-/// pub struct ErrorNotDir {
-///     name: String,
-///     info: PathBuf,
-/// }
-///
-/// impl ErrorNotDir {
-///     pub fn new(info: PathBuf) -> Self {
-///         Self {
-///             name: "error_not_dir".into(),
-///             info,
-///         }
-///     }
-/// }
-/// ```
-///
-/// When the `structural_renderer` feature is enabled, the struct also gets
-/// `#[derive(serde::Serialize)]`.
-///
-/// This macro is only available with the `extras` feature.
-#[cfg(feature = "extras")]
-#[proc_macro]
-pub fn pack_err(input: TokenStream) -> TokenStream {
-    pack_err::pack_err(input)
-}
-
-/// Like `pack_err!` but also marks the type for structured output
-/// (JSON / YAML / TOML / RON) via `StructuralData`.
-///
-/// # Syntax
-///
-/// ```rust,ignore
-/// pack_err_structural!(ErrorNotFound);
-/// pack_err_structural!(ErrorNotDir = PathBuf);
-/// ```
-///
-/// Requires the `structural_renderer` and `extras` features.
-#[cfg(all(feature = "structural_renderer", feature = "extras"))]
-#[proc_macro]
-pub fn pack_err_structural(input: TokenStream) -> TokenStream {
-    func::pack_err_structural::pack_err_structural(input)
-}
-
 /// Early-returns the error from a `Result`, converting the `Ok` branch to the
 /// next chain process value.
 ///
@@ -555,7 +396,7 @@ pub fn empty_result(input: TokenStream) -> TokenStream {
 ///
 /// The macro generates:
 ///
-/// 1. **Entry struct** — A `pack!`-style wrapper around `Vec<String>` (the raw args).
+/// 1. **Entry struct** — A newtype wrapper around `Vec<String>` (the raw args).
 ///    Registered in the program enum via `register_type!`.
 /// 2. **Dispatcher struct** — A hidden zero-sized struct implementing [`Dispatcher<Program>`]:
 ///    - `begin(args)` wraps `args` into the entry type and routes to chain.
@@ -664,78 +505,89 @@ pub fn dispatcher(input: TokenStream) -> TokenStream {
 /// # Sync Example
 ///
 /// ```rust,ignore
-/// use mingling::macros::{chain, pack, gen_program};
+/// use mingling::macros::{chain, gen_program};
+/// use mingling::{Grouped, Wrap};
 ///
-/// pack!(MyOutput = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct MyOutput(String);
 ///
 /// #[chain]
 /// fn greet(prev: HelloEntry) -> Next {
 ///     let name = prev.first().cloned().unwrap_or_else(|| "World".to_string());
-///     MyOutput::new(name)
+///     MyOutput(name)
 /// }
 /// ```
 ///
 /// # Sync Example with Resource Injection
 ///
 /// ```rust,ignore
-/// use mingling::macros::{chain, pack, gen_program};
+/// use mingling::macros::{chain, gen_program};
+/// use mingling::{Grouped, Wrap};
 ///
 /// #[derive(Default, Clone)]
 /// struct UserName(String);
 ///
-/// pack!(Greeting = String);
-/// pack!(DisplayCount = ());
+/// #[derive(Grouped, Wrap)]
+/// pub struct Greeting(String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct DisplayCount(());
 ///
 /// #[chain]
 /// fn greet(prev: HelloEntry, user_name: &UserName, count: &mut u64) -> Next {
 ///     *count += 1;
-///     Greeting::new(format!("Hello, {}!", user_name.0))
+///     Greeting(format!("Hello, {}!", user_name.0))
 /// }
 /// ```
 ///
 /// # Async Example (with `async` feature)
 ///
 /// ```rust,ignore
-/// use mingling::macros::{chain, pack, gen_program};
+/// use mingling::macros::{chain, gen_program};
+/// use mingling::{Grouped, Wrap};
 ///
-/// pack!(MyOutput = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct MyOutput(String);
 ///
 /// #[chain]
 /// async fn greet(prev: HelloEntry) -> Next {
 ///     let name = prev.first().cloned().unwrap_or_else(|| "World".to_string());
 ///     some_async_fn(&name).await;
-///     MyOutput::new(name)
+///     MyOutput(name)
 /// }
 /// ```
 ///
 /// # Async Example with Immutable Resource Injection
 ///
 /// ```rust,ignore
-/// use mingling::macros::{chain, pack, gen_program};
+/// use mingling::macros::{chain, gen_program};
+/// use mingling::{Grouped, Wrap};
 ///
-/// pack!(MyOutput = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct MyOutput(String);
 ///
 /// #[chain]
 /// async fn greet(prev: HelloEntry, prefix: &Prefix) -> Next {
 ///     let name = prev.first().cloned().unwrap_or_else(|| "World".to_string());
 ///     some_async_fn(&name).await;
-///     MyOutput::new(format!("{}{}", prefix.0, name))
+///     MyOutput(format!("{}{}", prefix.0, name))
 /// }
 /// ```
 ///
 /// # Async Example with Mutable Resource Injection
 ///
 /// ```rust,ignore
-/// use mingling::macros::{chain, pack, gen_program};
+/// use mingling::macros::{chain, gen_program};
+/// use mingling::{Grouped, Wrap};
 ///
-/// pack!(MyOutput = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct MyOutput(String);
 ///
 /// #[chain]
 /// async fn greet(prev: HelloEntry, ec: &mut ResExitCode) -> Next {
 ///     let name = prev.first().cloned().unwrap_or_else(|| "World".to_string());
 ///     ec.exit_code = 42;
 ///     some_async_fn(&name).await;
-///     MyOutput::new(name)
+///     MyOutput(name)
 /// }
 /// ```
 ///
@@ -777,10 +629,12 @@ pub fn chain(attr: TokenStream, item: TokenStream) -> TokenStream {
 /// # Example
 ///
 /// ```rust,ignore
-/// use mingling::macros::{renderer, pack, gen_program};
+/// use mingling::macros::{renderer, gen_program};
+/// use mingling::{Grouped, Wrap};
 /// use std::io::Write;
 ///
-/// pack!(Greeting = String);
+/// #[derive(Grouped, Wrap)]
+/// pub struct Greeting(String);
 ///
 /// #[renderer]
 /// fn render_greeting(prev: Greeting) -> RenderResult {
@@ -1063,7 +917,7 @@ pub fn dispatcher_clap(attr: TokenStream, item: TokenStream) -> TokenStream {
 /// Creates a packed entry value from a list of string literals.
 ///
 /// This is a convenience macro for constructing entry wrapper types (created
-/// via `pack!` or `dispatcher!`) with test data, typically used in unit tests
+/// via `dispatcher!`) with test data, typically used in unit tests
 /// or quick prototypes.
 ///
 /// # Syntax
@@ -1071,9 +925,9 @@ pub fn dispatcher_clap(attr: TokenStream, item: TokenStream) -> TokenStream {
 /// Two forms:
 ///
 /// ```rust,ignore
-/// // Named form — wraps into a specific pack type:
+/// // Named form — wraps into a specific entry type:
 /// entry!(MyEntry, ["a", "b", "c"])
-/// // Expands to: MyEntry::new(vec!["a".to_string(), "b".to_string(), "c".to_string()])
+/// // Expands to: MyEntry(vec!["a".to_string(), "b".to_string(), "c".to_string()])
 ///
 /// // Bracket form — returns Vec<String>.into() for type inference:
 /// entry!["a", "b", "c"]
@@ -1085,7 +939,7 @@ pub fn dispatcher_clap(attr: TokenStream, item: TokenStream) -> TokenStream {
 /// ```rust,ignore
 /// use mingling::macros::entry;
 ///
-/// // Named form (with a specific pack type):
+/// // Named form (with a specific entry type):
 /// let args = entry!(MyEntry, ["--name", "Alice", "--count", "5"]);
 ///
 /// // Bracket form (type inference):
@@ -1094,8 +948,7 @@ pub fn dispatcher_clap(attr: TokenStream, item: TokenStream) -> TokenStream {
 ///
 /// # See also
 ///
-/// - `pack!` — For creating the wrapper types used with `entry!`.
-/// - `dispatcher!` — Which implicitly creates entry types via `pack!`.
+/// - `dispatcher!` — Which implicitly creates entry types.
 #[cfg(feature = "extras")]
 #[proc_macro]
 pub fn entry(input: TokenStream) -> TokenStream {
@@ -1204,11 +1057,12 @@ pub fn register_dispatcher(input: TokenStream) -> TokenStream {
 /// # Example
 ///
 /// ```rust,ignore
-/// use mingling::macros::{help, pack, gen_program};
+/// use mingling::macros::{help, gen_program};
 /// use mingling::{prelude::*, setup::BasicProgramSetup, RenderResult};
 /// use std::io::Write;
 ///
-/// pack!(MyEntry = Vec<String>);
+/// #[derive(Grouped, Wrap)]
+/// pub struct MyEntry(Vec<String>);
 ///
 /// #[help]
 /// fn help_my_entry(prev: MyEntry) -> RenderResult {
@@ -1620,8 +1474,8 @@ pub fn derive_wrap(input: TokenStream) -> TokenStream {
 /// }
 /// ```
 ///
-/// This is equivalent to using `pack!` but works with custom structs that
-/// have named fields. For simple wrappers, prefer `pack!`.
+/// This is equivalent to using `#[derive(Grouped)]` but works with custom structs that
+/// have named fields.
 #[proc_macro_derive(Grouped, attributes(group))]
 pub fn derive_grouped(input: TokenStream) -> TokenStream {
     grouped::derive_grouped(input)
@@ -1813,7 +1667,7 @@ pub fn program_comp_gen(input: TokenStream) -> TokenStream {
 /// Registers a type into the global packed types registry for inclusion in
 /// the program enum generated by `gen_program!`.
 ///
-/// This macro is called internally by `pack!` and `#[derive(Grouped)]`(`macro.derive_grouped.html`)
+/// This macro is called internally by `#[derive(Grouped)]` (`macro.derive_grouped.html`)
 /// and is generally not needed in user code. However, it can be used for manual
 /// registration if you are implementing custom type registration outside of
 /// the standard macros.
@@ -1885,7 +1739,7 @@ pub fn program_fallback_gen(input: TokenStream) -> TokenStream {
 /// and its `ProgramCollect` implementation.
 ///
 /// This is the core code generation macro that:
-/// 1. Collects all registered types (from `pack!`, `#[derive(Grouped)]`, etc.) and
+/// 1. Collects all registered types (from `#[derive(Grouped)]`, etc.) and
 ///    creates an enum with each type as a variant.
 /// 2. Generates the `Display` implementation for the enum.
 /// 3. Generates the `ProgramCollect` implementation that dispatches to all
diff --git a/mingling_macros/src/systems.rs b/mingling_macros/src/systems.rs
index ef3624e..3279b51 100644
--- a/mingling_macros/src/systems.rs
+++ b/mingling_macros/src/systems.rs
@@ -1,8 +1,7 @@
-// Doc Not Optimize
 #[cfg(not(feature = "dispatch_tree"))]
 pub(crate) mod dispatch_list_gen;
+
 #[cfg(feature = "dispatch_tree")]
 pub(crate) mod dispatch_tree_gen;
+
 pub(crate) mod res_injection;
-#[cfg(feature = "structural_renderer")]
-pub(crate) mod structural_data;
diff --git a/mingling_macros/src/systems/structural_data.rs b/mingling_macros/src/systems/structural_data.rs
deleted file mode 100644
index ac9b1ca..0000000
--- a/mingling_macros/src/systems/structural_data.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-// Doc Not Optimize
-//! Legacy structural data module.
-//!
-//! Functions have been moved to:
-//! - `derive::structural_data`  — `derive_structural_data`
-//! - `func::pack_structural`    — `pack_structural`
-//! - `func::group_structural`   — `group_structural`
diff --git a/mingling_pathf/src/pattern_analyzer.rs b/mingling_pathf/src/pattern_analyzer.rs
index b7f923c..5b8b096 100644
--- a/mingling_pathf/src/pattern_analyzer.rs
+++ b/mingling_pathf/src/pattern_analyzer.rs
@@ -4,7 +4,7 @@
 //!
 //! It provides a pluggable architecture via the `AnalyzePattern` trait, allowing different
 //! syntactic patterns to be registered and applied. Built-in patterns cover common structures
-//! such as basic structs, packs, groups, derives, chains, renderers, help, completion, and
+//! such as basic structs, groups, derives, chains, renderers, help, completion, and
 //! dispatch patterns (both standard and clap-based).
 //!
 //! The entry points are:
@@ -18,14 +18,13 @@ use std::path::Path;
 use crate::error::MinglingPathfinderError;
 use crate::patterns::{
     ChainPattern, CommandPattern, CompletionPattern, DispatcherClapPattern, DispatcherPattern,
-    GroupPattern, GroupedDerivePattern, HelpPattern, MetadataPattern, PackPattern, RendererPattern,
+    GroupPattern, GroupedDerivePattern, HelpPattern, MetadataPattern, RendererPattern,
 };
 
 /// Creates a default `PatternAnalyzer` with all built-in patterns pre-registered.
 #[must_use]
 pub fn init() -> PatternAnalyzer {
     let mut analyzer = PatternAnalyzer::new();
-    analyzer.add_pattern(PackPattern);
     analyzer.add_pattern(GroupPattern);
     analyzer.add_pattern(GroupedDerivePattern);
     analyzer.add_pattern(ChainPattern);
diff --git a/mingling_pathf/src/patterns.rs b/mingling_pathf/src/patterns.rs
index fa0fc8b..43c60ac 100644
--- a/mingling_pathf/src/patterns.rs
+++ b/mingling_pathf/src/patterns.rs
@@ -10,7 +10,6 @@ pub use group::*;
 pub use grouped_derive::*;
 pub use help::*;
 pub use metadata::*;
-pub use pack::*;
 pub use renderer::*;
 
 mod chain;
@@ -22,5 +21,4 @@ mod group;
 mod grouped_derive;
 mod help;
 mod metadata;
-mod pack;
 mod renderer;
diff --git a/mingling_pathf/src/patterns/pack.rs b/mingling_pathf/src/patterns/pack.rs
deleted file mode 100644
index 10327a7..0000000
--- a/mingling_pathf/src/patterns/pack.rs
+++ /dev/null
@@ -1,104 +0,0 @@
-// Doc Not Optimize
-//! The `PackPattern` matches types defined by `pack!`, `pack_err!`, `pack_structural!`, and `pack_err_structural!` macros.
-//! It extracts the registered type name (e.g., `TypeName` from `pack!(TypeName = InnerType)`).
-//! This is used to track packed type definitions for code generation or analysis.
-
-use syn::Item;
-
-use crate::pattern_analyzer::{AnalyzeItem, AnalyzePattern};
-
-/// Matches types defined by `pack!`, `pack_err!`, `pack_structural!`, `pack_err_structural!` macros.
-///
-/// Covered forms:
-/// - `pack!(TypeName = InnerType)`
-/// - `pack! { TypeName = InnerType }`
-/// - `pack_err!(TypeName)`
-/// - `pack_err!(TypeName = InnerType)`
-/// - `pack_structural!` series same as above
-pub struct PackPattern;
-
-impl AnalyzePattern for PackPattern {
-    fn contains(&self, content: &str) -> bool {
-        content.contains("pack!")
-            || content.contains("pack_err!")
-            || content.contains("pack_structural!")
-            || content.contains("pack_err_structural!")
-    }
-
-    fn analyze(&self, content: &str) -> Vec<AnalyzeItem> {
-        let Ok(syntax) = syn::parse_file(content) else {
-            return Vec::new();
-        };
-
-        let mut items = Vec::new();
-
-        for item in &syntax.items {
-            match item {
-                // Top-level macro calls
-                Item::Macro(m) => {
-                    if let Some(name) = try_extract_pack_name(m) {
-                        items.push(AnalyzeItem::local(String::new(), name));
-                    }
-                }
-                // Macro calls inside inline modules
-                Item::Mod(item_mod) => {
-                    if let Some((_, nested)) = &item_mod.content {
-                        for n in nested {
-                            if let Item::Macro(m) = n
-                                && let Some(name) = try_extract_pack_name(m)
-                            {
-                                items.push(AnalyzeItem::local(item_mod.ident.to_string(), name));
-                            }
-                        }
-                    }
-                }
-                _ => {}
-            }
-        }
-
-        items
-    }
-}
-
-/// If the macro call is `pack!` / `pack_err!` / etc., extract the registered type name.
-fn try_extract_pack_name(m: &syn::ItemMacro) -> Option<String> {
-    let macro_name = m.mac.path.segments.last()?.ident.to_string();
-
-    match macro_name.as_str() {
-        "pack" | "pack_err" | "pack_structural" | "pack_err_structural" => {}
-        _ => return None,
-    }
-
-    let tokens = &m.mac.tokens;
-
-    // `pack!(T)` or `pack!(T = U)` — the first ident is the type name
-    // Parse simply with syn
-    if let Ok(ident) = syn::parse2::<syn::Ident>(tokens.clone()) {
-        // pack!(TypeName) — just a single ident
-        return Some(ident.to_string());
-    }
-
-    // Try to parse `Ident = Type`
-    // Clone tokens first to avoid partial consumption
-    let stream = tokens.clone();
-    let mut iter = stream.into_iter();
-
-    // Skip leading attributes/doc comments
-    loop {
-        if let proc_macro2::TokenTree::Ident(ident) = iter.next()? {
-            // Found the first ident, this is the type name
-            let type_name = ident.to_string();
-
-            // Check if `=` follows
-            if let Some(proc_macro2::TokenTree::Punct(p)) = iter.next()
-                && p.as_char() == '='
-            {
-                // pack!(TypeName = InnerType)
-                return Some(type_name);
-            }
-
-            // pack_err!(TypeName) — only a single ident
-            return Some(type_name);
-        }
-    }
-}
diff --git a/mingling_pathf/test/src/lib.rs b/mingling_pathf/test/src/lib.rs
index fff2597..22e1cc2 100644
--- a/mingling_pathf/test/src/lib.rs
+++ b/mingling_pathf/test/src/lib.rs
@@ -174,33 +174,6 @@ fn test_completion_analyze() {
 }
 
 #[test]
-fn test_pack_analyze() {
-    let analyzer = mingling_pathf::pattern_analyzer::init();
-    let file = current_dir().unwrap().join("src/test_files/test_pack.rs");
-
-    let r = analyzer.analyze_file(file).unwrap();
-    let required: Vec<&str> = vec![
-        "::ResultPack1",
-        "::ErrorPack1",
-        "::ErrorPack2",
-        "::ResultPack2",
-        "::ErrorPack3",
-        "::ErrorPack4",
-        "::sub::ResultPack1",
-        "::sub::ErrorPack1",
-        "::sub::ErrorPack2",
-        "::sub::ResultPack2",
-        "::sub::ErrorPack3",
-        "::sub::ErrorPack4",
-    ];
-
-    assert_eq!(r.len(), required.len());
-    for entry in &required {
-        assert!(r.contains(*entry), "Result should contain: {}", entry);
-    }
-}
-
-#[test]
 fn test_group_analyze() {
     let analyzer = mingling_pathf::pattern_analyzer::init();
     let file = current_dir().unwrap().join("src/test_files/test_group.rs");
diff --git a/mingling_pathf/test/src/test_files/test_pack.rs b/mingling_pathf/test/src/test_files/test_pack.rs
deleted file mode 100644
index 759e35f..0000000
--- a/mingling_pathf/test/src/test_files/test_pack.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-mingling::macros::pack!(ResultPack1 = String);
-mingling::macros::pack_err!(ErrorPack1);
-mingling::macros::pack_err!(ErrorPack2 = PathBuf);
-
-pack!(ResultPack2 = (u8, String));
-pack_err!(ErrorPack3);
-pack_err!(ErrorPack4 = PathBuf);
-
-pub mod sub {
-    mingling::macros::pack!(ResultPack1 = String);
-    mingling::macros::pack_err!(ErrorPack1);
-    mingling::macros::pack_err!(ErrorPack2 = PathBuf);
-
-    pack!(ResultPack2 = (u8, String));
-    pack_err!(ErrorPack3);
-    pack_err!(ErrorPack4 = PathBuf);
-}