"""Middleware for the Deep Agents agent.

## Overview

The LLM receives tools through two paths:

1. **SDK middleware** (this package) -- tools, system-prompt injection, and
   request interception that any SDK consumer gets automatically.
2. **Consumer-provided tools** -- plain callable functions passed via the
   `tools` parameter to `create_deep_agent()`. The CLI uses this path for
   lightweight, consumer-specific tools.

Both are merged by `create_deep_agent()` into the final tool set the LLM sees.

## Why middleware instead of plain tools?

Middleware subclasses `AgentMiddleware`, overriding its `wrap_model_call()`
hook that **intercepts every LLM request** before it is sent. This lets
middleware:

* **Filter tools dynamically** -- e.g. `FilesystemMiddleware` removes the
  `execute` tool at call-time when the resolved backend doesn't support it.
* **Inject system-prompt context** -- e.g. `MemoryMiddleware` and
  `SkillsMiddleware` inject relevant instructions into the system message on
  every call so the LLM knows how to use the tools they provide.
* **Transform messages** -- e.g. `SummarizationMiddleware` counts tokens,
  truncates old tool arguments, and replaces history with summaries when the
  context window fills up.
* **Maintain cross-turn state** -- middleware can read/write a typed state
  dict that persists across agent turns (e.g. summarization events).

A plain tool function in a `tools=[]` list cannot do any of this -- it is
only invoked *by* the LLM, not *before* the LLM call.

## When to use each path

Use **middleware** when the tool needs to:

* Modify the system prompt or tool list per-call
* Track state across turns
* Be available to all SDK consumers (not just the CLI)

Use a **plain tool** when:

* The function is stateless and self-contained
* No system-prompt or request modification is needed
* The tool is specific to a single consumer (e.g. CLI-only)
"""

from deepagents.middleware.filesystem import FilesystemMiddleware
from deepagents.middleware.memory import MemoryMiddleware
from deepagents.middleware.skills import SkillsMiddleware
from deepagents.middleware.subagents import CompiledSubAgent, SubAgent, SubAgentMiddleware
from deepagents.middleware.summarization import (
    SummarizationMiddleware,
    SummarizationToolMiddleware,
    create_summarization_tool_middleware,
)

__all__ = [
    "CompiledSubAgent",
    "FilesystemMiddleware",
    "MemoryMiddleware",
    "SkillsMiddleware",
    "SubAgent",
    "SubAgentMiddleware",
    "SummarizationMiddleware",
    "SummarizationToolMiddleware",
    "create_summarization_tool_middleware",
]