Files
MoviePilot/app/agent/middleware/skills.py
jxxghp afcc071d07 feat: optimize tool selection middleware to cache and reuse tool selection per agent run
- Refactor MoviePilotToolSelectorMiddleware to perform tool selection once per agent execution and cache the result in state, avoiding redundant LLM calls for each model round.
- Add abefore_agent to select tools at the start of agent execution and store selected tool names in state.
- Update awrap_model_call to reuse cached tool selection from state for subsequent model calls.
- Enhance test coverage for tool selection caching and reuse logic.
- Improve error logging in skill version extraction.
2026-04-30 18:29:54 +08:00

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import re
import shutil
from collections.abc import Awaitable, Callable
from pathlib import Path
from typing import Annotated, List
from typing import NotRequired, TypedDict
import yaml # noqa
from anyio import Path as AsyncPath
from langchain.agents.middleware.types import (
AgentMiddleware,
AgentState,
ContextT,
ModelRequest,
ModelResponse,
ResponseT,
)
from langchain.agents.middleware.types import PrivateStateAttr # noqa
from langchain_core.runnables import RunnableConfig
from langgraph.runtime import Runtime
from app.agent.middleware.utils import append_to_system_message
from app.log import logger
# 安全提示: SKILL.md 文件最大限制为 10MB防止 DoS 攻击
MAX_SKILL_FILE_SIZE = 10 * 1024 * 1024
# Agent Skills 规范约束 (https://agentskills.io/specification)
MAX_SKILL_NAME_LENGTH = 64
MAX_SKILL_DESCRIPTION_LENGTH = 1024
MAX_SKILL_COMPATIBILITY_LENGTH = 500
class SkillMetadata(TypedDict):
"""Skill 元数据,符合 Agent Skills 规范。"""
path: str
"""SKILL.md 文件路径。"""
id: str
"""Skill 标识符。
约束: 1-64 字符,仅限小写字母/数字/连字符,不能以连字符开头或结尾,无连续连字符,需与父目录名一致。
"""
name: str
"""Skill 名称。
约束: Skill中文描述。
"""
version: int
"""Skill 版本号。
用于内置技能的版本管理,同步时比较版本号决定是否覆盖用户目录中的旧版本。
"""
description: str
"""Skill 功能描述。
约束: 1-1024 字符,应说明功能及适用场景。
"""
license: str | None
"""许可证信息。"""
compatibility: str | None
"""环境依赖或兼容性要求 (最多 500 字符)。"""
metadata: dict[str, str]
"""附加元数据。"""
allowed_tools: list[str]
"""(实验性) Skill 建议使用的工具列表。"""
class SkillsState(AgentState):
"""skills 中间件状态。"""
skills_metadata: NotRequired[Annotated[list[SkillMetadata], PrivateStateAttr]]
"""已加载的 skill 元数据列表,不传播给父 agent。"""
class SkillsStateUpdate(TypedDict):
"""skills 中间件状态更新项。"""
skills_metadata: list[SkillMetadata]
"""待合并的 skill 元数据列表。"""
def _parse_skill_metadata( # noqa: C901
content: str,
skill_path: str,
skill_id: str,
) -> SkillMetadata | None:
"""从 SKILL.md 内容中解析 YAML 前言并验证元数据。"""
if len(content) > MAX_SKILL_FILE_SIZE:
logger.warning(
"Skipping %s: content too large (%d bytes)", skill_path, len(content)
)
return None
# 匹配 --- 分隔的 YAML 前言
frontmatter_pattern = r"^---\s*\n(.*?)\n---\s*\n"
match = re.match(frontmatter_pattern, content, re.DOTALL)
if not match:
logger.warning("Skipping %s: no valid YAML frontmatter found", skill_path)
return None
frontmatter_str = match.group(1)
# 解析 YAML
try:
frontmatter_data = yaml.safe_load(frontmatter_str)
except yaml.YAMLError as e:
logger.warning("Invalid YAML in %s: %s", skill_path, e)
return None
if not isinstance(frontmatter_data, dict):
logger.warning("Skipping %s: frontmatter is not a mapping", skill_path)
return None
# SKill名称和描述
name = str(frontmatter_data.get("name", "")).strip()
description = str(frontmatter_data.get("description", "")).strip()
if not name or not description:
logger.warning(
"Skipping %s: missing required 'name' or 'description'", skill_path
)
return None
description_str = description
if len(description_str) > MAX_SKILL_DESCRIPTION_LENGTH:
logger.warning(
"Description exceeds %d characters in %s, truncating",
MAX_SKILL_DESCRIPTION_LENGTH,
skill_path,
)
description_str = description_str[:MAX_SKILL_DESCRIPTION_LENGTH]
# 可选的工具列表,支持空格或逗号分隔
raw_tools = frontmatter_data.get("allowed-tools")
if isinstance(raw_tools, str):
allowed_tools = [
t.strip(",") # 兼容 Claude Code 风格的逗号分隔
for t in raw_tools.split()
if t.strip(",")
]
else:
if raw_tools is not None:
logger.warning(
"Ignoring non-string 'allowed-tools' in %s (got %s)",
skill_path,
type(raw_tools).__name__,
)
allowed_tools = []
# 能力或环境兼容性说明,最多 500 字符
compatibility_str = str(frontmatter_data.get("compatibility", "")).strip() or None
if compatibility_str and len(compatibility_str) > MAX_SKILL_COMPATIBILITY_LENGTH:
logger.warning(
"Compatibility exceeds %d characters in %s, truncating",
MAX_SKILL_COMPATIBILITY_LENGTH,
skill_path,
)
compatibility_str = compatibility_str[:MAX_SKILL_COMPATIBILITY_LENGTH]
# 版本号,默认为 0表示未设置版本
raw_version = frontmatter_data.get("version")
version = 0
if raw_version is not None:
try:
version = int(raw_version)
except (ValueError, TypeError):
logger.warning(
"Invalid 'version' in %s (got %r), defaulting to 0",
skill_path,
raw_version,
)
return SkillMetadata(
id=skill_id,
name=name,
version=version,
description=description_str,
path=skill_path,
metadata=_validate_metadata(frontmatter_data.get("metadata", {}), skill_path),
license=str(frontmatter_data.get("license", "")).strip() or None,
compatibility=compatibility_str,
allowed_tools=allowed_tools,
)
def _validate_metadata(
raw: object,
skill_path: str,
) -> dict[str, str]:
"""验证并规范化 YAML 前言中的元数据字段,确保为 dict[str, str] 类型。"""
if not isinstance(raw, dict):
if raw:
logger.warning(
"Ignoring non-dict metadata in %s (got %s)",
skill_path,
type(raw).__name__,
)
return {}
return {str(k): str(v) for k, v in raw.items()}
def _format_skill_annotations(skill: SkillMetadata) -> str:
"""构建许可证和兼容性说明字符串。"""
parts: list[str] = []
if skill.get("license"):
parts.append(f"License: {skill['license']}")
if skill.get("compatibility"):
parts.append(f"Compatibility: {skill['compatibility']}")
return ", ".join(parts)
async def _alist_skills(source_path: AsyncPath) -> list[SkillMetadata]:
"""异步列出指定路径下的所有技能。
扫描包含 SKILL.md 的目录并解析其元数据。
"""
skills: list[SkillMetadata] = []
# 查找所有技能目录 (包含 SKILL.md 的目录)
skill_dirs: List[AsyncPath] = []
async for path in source_path.iterdir():
if await path.is_dir() and await (path / "SKILL.md").is_file():
skill_dirs.append(path)
if not skill_dirs:
return []
# 解析已下载的 SKILL.md
for skill_path in skill_dirs:
skill_md_path = skill_path / "SKILL.md"
skill_content = await skill_md_path.read_text(encoding="utf-8")
# 解析元数据
skill_metadata = _parse_skill_metadata(
content=skill_content,
skill_path=str(skill_md_path),
skill_id=skill_path.name,
)
if skill_metadata:
skills.append(skill_metadata)
return skills
SKILLS_SYSTEM_PROMPT = """
<skills_system>
You have access to a skills library that provides specialized capabilities and domain knowledge.
{skills_locations}
**Available Skills:**
{skills_list}
**How to Use Skills (Progressive Disclosure):**
Skills follow a **progressive disclosure** pattern - you see their name and description above, but only read full instructions when needed:
1. **Recognize when a skill applies**: Check if the user's task matches a skill's description
2. **Read the skill's full instructions**: Use the path shown in the skill list above
3. **Follow the skill's instructions**: SKILL.md contains step-by-step workflows, best practices, and examples
4. **Access supporting files**: Skills may include helper scripts, configs, or reference docs - use absolute paths
**Creating New Skills:**
When you identify a repetitive complex workflow or specialized task that would benefit from being a skill, you can create one:
1. **Directory Structure**: Create a new directory in one of the skills locations. The directory name is the `skill-id`.
- Path format: `<skills_location>/<skill-id>/SKILL.md`
- `skill-id` constraints: 1-64 characters, lowercase letters, numbers, and hyphens only.
2. **SKILL.md Format**: Must start with a YAML frontmatter followed by markdown instructions.
```markdown
---
name: Brief tool name (Chinese)
description: Detailed functional description and use cases (1-1024 chars)
allowed-tools: "tool1 tool2" (optional, space-separated list of recommended tools)
compatibility: "Environment requirements" (optional, max 500 chars)
---
# Skill Instructions
Step-by-step workflows, best practices, and examples go here.
```
3. **Supporting Files**: You can add `.py` scripts, `.yaml` configs, or other files within the same skill directory. Reference them using absolute paths in `SKILL.md`.
**When to Use Skills:**
- User's request matches a skill's domain (e.g., "research X" -> web-research skill)
- You need specialized knowledge or structured workflows
- A skill provides proven patterns for complex tasks
**Executing Skill Scripts:**
Skills may contain Python scripts or other executable files. Always use absolute paths from the skill list.
**Example Workflow:**
User: "Can you research the latest developments in quantum computing?"
1. Check available skills -> See "web-research" skill with its path
2. Read the skill using the path shown
3. Follow the skill's research workflow (search -> organize -> synthesize)
4. Use any helper scripts with absolute paths
Remember: Skills make you more capable and consistent. When in doubt, check if a skill exists for the task!
</skills_system>
"""
def _extract_version(skill_md: Path) -> int:
"""从 SKILL.md 文件中快速提取 version 字段,无法提取时返回 0。"""
try:
content = skill_md.read_text(encoding="utf-8")
except Exception as err:
print(err)
return 0
match = re.match(r"^---\s*\n(.*?)\n---\s*\n", content, re.DOTALL)
if not match:
return 0
try:
frontmatter = yaml.safe_load(match.group(1))
except yaml.YAMLError:
return 0
if not isinstance(frontmatter, dict):
return 0
raw = frontmatter.get("version")
if raw is None:
return 0
try:
return int(raw)
except (ValueError, TypeError):
return 0
def _sync_bundled_skills(bundled_dir: Path, target_dir: Path) -> None:
"""将项目自带的技能同步到用户目录。
- 目标目录中不存在对应技能子目录时,直接复制。
- 目标目录中已存在时,比较内置与用户目录中 SKILL.md 的 version 字段:
- 内置版本更高时,直接覆盖用户目录中的旧版本。
- 版本相同或用户版本更高时,跳过。
- 内置 SKILL.md 无 version 字段(视为 0不覆盖。
Parameters
----------
bundled_dir : Path
项目内置技能目录(如 ``ROOT_PATH / "skills"``)。
target_dir : Path
用户配置技能目录(如 ``CONFIG_PATH / "agent" / "skills"``)。
"""
if not bundled_dir.is_dir():
return
target_dir.mkdir(parents=True, exist_ok=True)
for skill_src in bundled_dir.iterdir():
if not skill_src.is_dir():
continue
skill_md = skill_src / "SKILL.md"
if not skill_md.is_file():
continue
skill_dst = target_dir / skill_src.name
if not skill_dst.exists():
# 目标不存在,直接复制
try:
shutil.copytree(str(skill_src), str(skill_dst))
logger.info(
"已自动复制内置技能 '%s' -> '%s'", skill_src.name, skill_dst
)
except Exception as e:
logger.warning("复制内置技能 '%s' 失败: %s", skill_src.name, e)
continue
# 目标已存在,比较版本号
bundled_version = _extract_version(skill_md)
if bundled_version <= 0:
# 内置技能无版本号,保持旧逻辑不覆盖
continue
user_skill_md = skill_dst / "SKILL.md"
user_version = _extract_version(user_skill_md) if user_skill_md.is_file() else 0
if bundled_version <= user_version:
# 用户版本 >= 内置版本,跳过
continue
# 内置版本更高,删除旧版本后覆盖
try:
shutil.rmtree(str(skill_dst))
shutil.copytree(str(skill_src), str(skill_dst))
logger.info(
"已更新内置技能 '%s' (v%d -> v%d)",
skill_src.name,
user_version,
bundled_version,
)
except Exception as e:
logger.warning("更新内置技能 '%s' 失败: %s", skill_src.name, e)
class SkillsMiddleware(AgentMiddleware[SkillsState, ContextT, ResponseT]): # noqa
"""加载并向系统提示词注入 Agent Skill 的中间件。
按源顺序加载 Skill后加载的会覆盖重名的。
启动时自动将项目内置技能bundled_skills_dir同步到用户技能目录。
"""
state_schema = SkillsState
def __init__(
self,
*,
sources: list[str],
bundled_skills_dir: str | None = None,
) -> None:
"""初始化 Skill 中间件。
Parameters
----------
sources : list[str]
用户技能目录列表。
bundled_skills_dir : str | None
项目内置技能目录路径。若提供,在首次加载前会将其中不存在于
sources 首个目录的技能自动复制过去。
"""
self.sources = sources
self.bundled_skills_dir = bundled_skills_dir
self.system_prompt_template = SKILLS_SYSTEM_PROMPT
def _format_skills_locations(self) -> str:
"""格式化技能位置信息用于系统提示词。"""
locations = []
for i, source_path in enumerate(self.sources):
suffix = " (higher priority)" if i == len(self.sources) - 1 else ""
locations.append(f"**MoviePilot Skills**: `{source_path}`{suffix}")
return "\n".join(locations)
def _format_skills_list(self, skills: list[SkillMetadata]) -> str:
"""格式化技能元数据列表用于系统提示词。"""
if not skills:
paths = [f"{source_path}" for source_path in self.sources]
return f"(No skills available yet. You can create skills in {' or '.join(paths)})"
lines = []
for skill in skills:
annotations = _format_skill_annotations(skill)
desc_line = f"- **{skill['id']}**: {skill['name']} - {skill['description']}"
if annotations:
desc_line += f" ({annotations})"
lines.append(desc_line)
if skill["allowed_tools"]:
lines.append(f" -> Allowed tools: {', '.join(skill['allowed_tools'])}")
lines.append(f" -> Read `{skill['path']}` for full instructions")
return "\n".join(lines)
def modify_request(self, request: ModelRequest[ContextT]) -> ModelRequest[ContextT]:
"""将技能文档注入模型请求的系统消息中。"""
skills_metadata = request.state.get("skills_metadata", []) # noqa
skills_locations = self._format_skills_locations()
skills_list = self._format_skills_list(skills_metadata)
skills_section = self.system_prompt_template.format(
skills_locations=skills_locations,
skills_list=skills_list,
)
new_system_message = append_to_system_message(
request.system_message, skills_section
)
return request.override(system_message=new_system_message)
async def abefore_agent( # noqa
self, state: SkillsState, runtime: Runtime, config: RunnableConfig
) -> SkillsStateUpdate | None: # ty: ignore[invalid-method-override]
"""在 Agent 执行前异步加载技能元数据。
每个会话仅加载一次。若 state 中已有则跳过。
首次加载时,会先将内置技能同步到用户目录(如不存在)。
"""
# 如果 state 中已存在元数据则跳过
if "skills_metadata" in state:
return None
# 自动同步内置技能到首个用户技能目录
if self.bundled_skills_dir and self.sources:
bundled = Path(self.bundled_skills_dir)
target = Path(self.sources[0])
try:
_sync_bundled_skills(bundled, target)
except Exception as e:
logger.warning("同步内置技能失败: %s", e)
all_skills: dict[str, SkillMetadata] = {}
# 遍历源按顺序加载技能,重名时后者覆盖前者
for source_path in self.sources:
skill_source_path = AsyncPath(source_path)
if not await skill_source_path.exists():
await skill_source_path.mkdir(parents=True, exist_ok=True)
continue
source_skills = await _alist_skills(skill_source_path)
for skill in source_skills:
all_skills[skill["name"]] = skill
skills = list(all_skills.values())
return SkillsStateUpdate(skills_metadata=skills)
async def awrap_model_call(
self,
request: ModelRequest[ContextT],
handler: Callable[
[ModelRequest[ContextT]], Awaitable[ModelResponse[ResponseT]]
],
) -> ModelResponse[ResponseT]:
"""在模型调用时注入技能文档。"""
modified_request = self.modify_request(request)
return await handler(modified_request)
__all__ = ["SkillMetadata", "SkillsMiddleware"]