# `CMDCTest.Plugin.Spy`
[🔗](https://github.com/tupleyun/cmdc_test/blob/v0.1.0/lib/cmdc_test/plugin.ex#L109)

Spy Plugin — 注入任意 handler 函数到 Agent Plugin Pipeline 的轻量方式。

替代 `with_mock_plugin` macro，避免引入 `:meck` 重依赖；
用户传入 anonymous handler 函数，Spy 在每次 `handle_event/3` 调用时转发给它。

## 使用

    {:ok, session} =
      CMDC.create_agent(
        model: "mock:test",
        plugins: [
          {CMDCTest.Plugin.Spy,
           handler: fn
             {:before_tool, name, args}, state, _ctx ->
               send(self(), {:tool_intercepted, name, args})
               {:continue, state}

             _event, state, _ctx ->
               {:continue, state}
           end,
           priority: 100}
        ]
      )

## 配置

- `:handler`（必填）— `(event, plugin_state, ctx) -> action_tuple`
- `:priority` — 优先级，默认 500
- `:initial_state` — `:handler` 看到的 `plugin_state`，默认 `%{}`

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*Consult [api-reference.md](api-reference.md) for complete listing*