feat: add DeerFlowClient for embedded programmatic access (#926)

Add `DeerFlowClient` class that provides direct in-process access to
DeerFlow's agent and Gateway capabilities without requiring LangGraph
Server or Gateway API processes. This enables users to import and use
DeerFlow as a Python library.

Co-authored-by: greatmengqi <chenmengqi.0376@bytedance.com>
This commit is contained in:
greatmengqi
2026-02-28 14:38:15 +08:00
committed by GitHub
parent 5ad8a657f4
commit 9d48c42a20
7 changed files with 2450 additions and 2 deletions

786
backend/src/client.py Normal file
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"""DeerFlowClient — Embedded Python client for DeerFlow agent system.
Provides direct programmatic access to DeerFlow's agent capabilities
without requiring LangGraph Server or Gateway API processes.
Usage:
from src.client import DeerFlowClient
client = DeerFlowClient()
response = client.chat("Analyze this paper for me", thread_id="my-thread")
print(response)
# Streaming
for event in client.stream("hello"):
print(event)
"""
import asyncio
import json
import logging
import mimetypes
import re
import shutil
import tempfile
import uuid
import zipfile
from collections.abc import Generator
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any
from langchain.agents import create_agent
from langchain_core.messages import AIMessage, HumanMessage, ToolMessage
from langchain_core.runnables import RunnableConfig
from src.agents.lead_agent.agent import _build_middlewares
from src.agents.lead_agent.prompt import apply_prompt_template
from src.agents.thread_state import ThreadState
from src.config.app_config import get_app_config, reload_app_config
from src.config.extensions_config import ExtensionsConfig, SkillStateConfig, get_extensions_config, reload_extensions_config
from src.models import create_chat_model
from src.config.paths import get_paths
logger = logging.getLogger(__name__)
@dataclass
class StreamEvent:
"""A single event from the streaming agent response.
Attributes:
type: Event type — "message", "tool_call", "tool_result", "title", or "done".
data: Event payload. Contents vary by type.
"""
type: str
data: dict[str, Any] = field(default_factory=dict)
class DeerFlowClient:
"""Embedded Python client for DeerFlow agent system.
Provides direct programmatic access to DeerFlow's agent capabilities
without requiring LangGraph Server or Gateway API processes.
Note:
Multi-turn conversations require a ``checkpointer``. Without one,
each ``stream()`` / ``chat()`` call is stateless — ``thread_id``
is only used for file isolation (uploads / artifacts).
The system prompt (including date, memory, and skills context) is
generated when the internal agent is first created and cached until
the configuration key changes. Call :meth:`reset_agent` to force
a refresh in long-running processes.
Example::
from src.client import DeerFlowClient
client = DeerFlowClient()
# Simple one-shot
print(client.chat("hello"))
# Streaming
for event in client.stream("hello"):
print(event.type, event.data)
# Configuration queries
print(client.list_models())
print(client.list_skills())
"""
def __init__(
self,
config_path: str | None = None,
checkpointer=None,
*,
model_name: str | None = None,
thinking_enabled: bool = True,
subagent_enabled: bool = False,
plan_mode: bool = False,
):
"""Initialize the client.
Loads configuration but defers agent creation to first use.
Args:
config_path: Path to config.yaml. Uses default resolution if None.
checkpointer: LangGraph checkpointer instance for state persistence.
Required for multi-turn conversations on the same thread_id.
Without a checkpointer, each call is stateless.
model_name: Override the default model name from config.
thinking_enabled: Enable model's extended thinking.
subagent_enabled: Enable subagent delegation.
plan_mode: Enable TodoList middleware for plan mode.
"""
if config_path is not None:
reload_app_config(config_path)
self._app_config = get_app_config()
self._checkpointer = checkpointer
self._model_name = model_name
self._thinking_enabled = thinking_enabled
self._subagent_enabled = subagent_enabled
self._plan_mode = plan_mode
# Lazy agent — created on first call, recreated when config changes.
self._agent = None
self._agent_config_key: tuple | None = None
def reset_agent(self) -> None:
"""Force the internal agent to be recreated on the next call.
Use this after external changes (e.g. memory updates, skill
installations) that should be reflected in the system prompt
or tool set.
"""
self._agent = None
self._agent_config_key = None
# ------------------------------------------------------------------
# Internal helpers
# ------------------------------------------------------------------
@staticmethod
def _atomic_write_json(path: Path, data: dict) -> None:
"""Write JSON to *path* atomically (temp file + replace)."""
fd = tempfile.NamedTemporaryFile(
mode="w", dir=path.parent, suffix=".tmp", delete=False,
)
try:
json.dump(data, fd, indent=2)
fd.close()
Path(fd.name).replace(path)
except BaseException:
fd.close()
Path(fd.name).unlink(missing_ok=True)
raise
def _get_runnable_config(self, thread_id: str, **overrides) -> RunnableConfig:
"""Build a RunnableConfig for agent invocation."""
configurable = {
"thread_id": thread_id,
"model_name": overrides.get("model_name", self._model_name),
"thinking_enabled": overrides.get("thinking_enabled", self._thinking_enabled),
"is_plan_mode": overrides.get("plan_mode", self._plan_mode),
"subagent_enabled": overrides.get("subagent_enabled", self._subagent_enabled),
}
return RunnableConfig(
configurable=configurable,
recursion_limit=overrides.get("recursion_limit", 100),
)
def _ensure_agent(self, config: RunnableConfig):
"""Create (or recreate) the agent when config-dependent params change."""
cfg = config.get("configurable", {})
key = (
cfg.get("model_name"),
cfg.get("thinking_enabled"),
cfg.get("is_plan_mode"),
cfg.get("subagent_enabled"),
)
if self._agent is not None and self._agent_config_key == key:
return
thinking_enabled = cfg.get("thinking_enabled", True)
model_name = cfg.get("model_name")
subagent_enabled = cfg.get("subagent_enabled", False)
max_concurrent_subagents = cfg.get("max_concurrent_subagents", 3)
kwargs: dict[str, Any] = {
"model": create_chat_model(name=model_name, thinking_enabled=thinking_enabled),
"tools": self._get_tools(model_name=model_name, subagent_enabled=subagent_enabled),
"middleware": _build_middlewares(config, model_name=model_name),
"system_prompt": apply_prompt_template(
subagent_enabled=subagent_enabled,
max_concurrent_subagents=max_concurrent_subagents,
),
"state_schema": ThreadState,
}
if self._checkpointer is not None:
kwargs["checkpointer"] = self._checkpointer
self._agent = create_agent(**kwargs)
self._agent_config_key = key
logger.info("Agent created: model=%s, thinking=%s", model_name, thinking_enabled)
@staticmethod
def _get_tools(*, model_name: str | None, subagent_enabled: bool):
"""Lazy import to avoid circular dependency at module level."""
from src.tools import get_available_tools
return get_available_tools(model_name=model_name, subagent_enabled=subagent_enabled)
@staticmethod
def _extract_text(content) -> str:
"""Extract plain text from AIMessage content (str or list of blocks)."""
if isinstance(content, str):
return content
if isinstance(content, list):
parts = []
for block in content:
if isinstance(block, str):
parts.append(block)
elif isinstance(block, dict) and block.get("type") == "text":
parts.append(block["text"])
return "\n".join(parts) if parts else ""
return str(content)
# ------------------------------------------------------------------
# Public API — conversation
# ------------------------------------------------------------------
def stream(
self,
message: str,
*,
thread_id: str | None = None,
**kwargs,
) -> Generator[StreamEvent, None, None]:
"""Stream a conversation turn, yielding events incrementally.
Each call sends one user message and yields events until the agent
finishes its turn. A ``checkpointer`` must be provided at init time
for multi-turn context to be preserved across calls.
Args:
message: User message text.
thread_id: Thread ID for conversation context. Auto-generated if None.
**kwargs: Override client defaults (model_name, thinking_enabled,
plan_mode, subagent_enabled, recursion_limit).
Yields:
StreamEvent with one of:
- type="message" data={"content": str}
- type="tool_call" data={"name": str, "args": dict, "id": str}
- type="tool_result" data={"name": str, "content": str, "tool_call_id": str}
- type="title" data={"title": str}
- type="done" data={}
"""
if thread_id is None:
thread_id = str(uuid.uuid4())
config = self._get_runnable_config(thread_id, **kwargs)
self._ensure_agent(config)
state: dict[str, Any] = {"messages": [HumanMessage(content=message)]}
context = {"thread_id": thread_id}
seen_ids: set[str] = set()
last_title: str | None = None
for chunk in self._agent.stream(state, config=config, context=context, stream_mode="values"):
messages = chunk.get("messages", [])
for msg in messages:
msg_id = getattr(msg, "id", None)
if msg_id and msg_id in seen_ids:
continue
if msg_id:
seen_ids.add(msg_id)
if isinstance(msg, AIMessage):
if msg.tool_calls:
for tc in msg.tool_calls:
yield StreamEvent(
type="tool_call",
data={"name": tc["name"], "args": tc["args"], "id": tc.get("id")},
)
text = self._extract_text(msg.content)
if text:
yield StreamEvent(type="message", data={"content": text})
elif isinstance(msg, ToolMessage):
yield StreamEvent(
type="tool_result",
data={
"name": getattr(msg, "name", None),
"content": msg.content if isinstance(msg.content, str) else str(msg.content),
"tool_call_id": getattr(msg, "tool_call_id", None),
},
)
# Title changes
title = chunk.get("title")
if title and title != last_title:
last_title = title
yield StreamEvent(type="title", data={"title": title})
yield StreamEvent(type="done", data={})
def chat(self, message: str, *, thread_id: str | None = None, **kwargs) -> str:
"""Send a message and return the final text response.
Convenience wrapper around :meth:`stream` that returns only the
**last** ``message`` event's text. If the agent emits multiple
message segments in one turn, intermediate segments are discarded.
Use :meth:`stream` directly to capture all events.
Args:
message: User message text.
thread_id: Thread ID for conversation context. Auto-generated if None.
**kwargs: Override client defaults (same as stream()).
Returns:
The last AI message text, or empty string if no response.
"""
last_text = ""
for event in self.stream(message, thread_id=thread_id, **kwargs):
if event.type == "message":
last_text = event.data.get("content", "")
return last_text
# ------------------------------------------------------------------
# Public API — configuration queries
# ------------------------------------------------------------------
def list_models(self) -> list[dict]:
"""List available models from configuration.
Returns:
List of model config dicts.
"""
return [model.model_dump() for model in self._app_config.models]
def list_skills(self, enabled_only: bool = False) -> list[dict]:
"""List available skills.
Args:
enabled_only: If True, only return enabled skills.
Returns:
List of skill info dicts with name, description, category, enabled.
"""
from src.skills.loader import load_skills
return [
{
"name": s.name,
"description": s.description,
"category": s.category,
"enabled": s.enabled,
}
for s in load_skills(enabled_only=enabled_only)
]
def get_memory(self) -> dict:
"""Get current memory data.
Returns:
Memory data dict (see src/agents/memory/updater.py for structure).
"""
from src.agents.memory.updater import get_memory_data
return get_memory_data()
def get_model(self, name: str) -> dict | None:
"""Get a specific model's configuration by name.
Args:
name: Model name.
Returns:
Model config dict, or None if not found.
"""
model = self._app_config.get_model_config(name)
return model.model_dump() if model is not None else None
# ------------------------------------------------------------------
# Public API — MCP configuration
# ------------------------------------------------------------------
def get_mcp_config(self) -> dict[str, dict]:
"""Get MCP server configurations.
Returns:
Dict mapping server name to its config dict.
"""
config = get_extensions_config()
return {name: server.model_dump() for name, server in config.mcp_servers.items()}
def update_mcp_config(self, mcp_servers: dict[str, dict]) -> dict[str, dict]:
"""Update MCP server configurations.
Writes to extensions_config.json and reloads the cache.
Args:
mcp_servers: Dict mapping server name to config dict.
Each value should contain keys like enabled, type, command, args, env, url, etc.
Returns:
The updated MCP config.
Raises:
OSError: If the config file cannot be written.
"""
config_path = ExtensionsConfig.resolve_config_path()
if config_path is None:
raise FileNotFoundError(
"Cannot locate extensions_config.json. "
"Pass config_path to DeerFlowClient or set DEER_FLOW_HOME."
)
current_config = get_extensions_config()
config_data = {
"mcpServers": mcp_servers,
"skills": {name: {"enabled": skill.enabled} for name, skill in current_config.skills.items()},
}
self._atomic_write_json(config_path, config_data)
self._agent = None
reloaded = reload_extensions_config()
return {name: server.model_dump() for name, server in reloaded.mcp_servers.items()}
# ------------------------------------------------------------------
# Public API — skills management
# ------------------------------------------------------------------
def get_skill(self, name: str) -> dict | None:
"""Get a specific skill by name.
Args:
name: Skill name.
Returns:
Skill info dict, or None if not found.
"""
from src.skills.loader import load_skills
skill = next((s for s in load_skills(enabled_only=False) if s.name == name), None)
if skill is None:
return None
return {
"name": skill.name,
"description": skill.description,
"license": skill.license,
"category": skill.category,
"enabled": skill.enabled,
}
def update_skill(self, name: str, *, enabled: bool) -> dict:
"""Update a skill's enabled status.
Args:
name: Skill name.
enabled: New enabled status.
Returns:
Updated skill info dict.
Raises:
ValueError: If the skill is not found.
OSError: If the config file cannot be written.
"""
from src.skills.loader import load_skills
skills = load_skills(enabled_only=False)
skill = next((s for s in skills if s.name == name), None)
if skill is None:
raise ValueError(f"Skill '{name}' not found")
config_path = ExtensionsConfig.resolve_config_path()
if config_path is None:
raise FileNotFoundError(
"Cannot locate extensions_config.json. "
"Pass config_path to DeerFlowClient or set DEER_FLOW_HOME."
)
extensions_config = get_extensions_config()
extensions_config.skills[name] = SkillStateConfig(enabled=enabled)
config_data = {
"mcpServers": {n: s.model_dump() for n, s in extensions_config.mcp_servers.items()},
"skills": {n: {"enabled": sc.enabled} for n, sc in extensions_config.skills.items()},
}
self._atomic_write_json(config_path, config_data)
self._agent = None
reload_extensions_config()
updated = next((s for s in load_skills(enabled_only=False) if s.name == name), None)
if updated is None:
raise RuntimeError(f"Skill '{name}' disappeared after update")
return {
"name": updated.name,
"description": updated.description,
"license": updated.license,
"category": updated.category,
"enabled": updated.enabled,
}
def install_skill(self, skill_path: str | Path) -> dict:
"""Install a skill from a .skill archive (ZIP).
Args:
skill_path: Path to the .skill file.
Returns:
Dict with success, skill_name, message.
Raises:
FileNotFoundError: If the file does not exist.
ValueError: If the file is invalid.
"""
from src.gateway.routers.skills import _validate_skill_frontmatter
from src.skills.loader import get_skills_root_path
path = Path(skill_path)
if not path.exists():
raise FileNotFoundError(f"Skill file not found: {skill_path}")
if not path.is_file():
raise ValueError(f"Path is not a file: {skill_path}")
if path.suffix != ".skill":
raise ValueError("File must have .skill extension")
if not zipfile.is_zipfile(path):
raise ValueError("File is not a valid ZIP archive")
skills_root = get_skills_root_path()
custom_dir = skills_root / "custom"
custom_dir.mkdir(parents=True, exist_ok=True)
with tempfile.TemporaryDirectory() as tmp:
tmp_path = Path(tmp)
with zipfile.ZipFile(path, "r") as zf:
total_size = sum(info.file_size for info in zf.infolist())
if total_size > 100 * 1024 * 1024:
raise ValueError("Skill archive too large when extracted (>100MB)")
for info in zf.infolist():
if Path(info.filename).is_absolute() or ".." in Path(info.filename).parts:
raise ValueError(f"Unsafe path in archive: {info.filename}")
zf.extractall(tmp_path)
for p in tmp_path.rglob("*"):
if p.is_symlink():
p.unlink()
items = list(tmp_path.iterdir())
if not items:
raise ValueError("Skill archive is empty")
skill_dir = items[0] if len(items) == 1 and items[0].is_dir() else tmp_path
is_valid, message, skill_name = _validate_skill_frontmatter(skill_dir)
if not is_valid:
raise ValueError(f"Invalid skill: {message}")
if not re.fullmatch(r"[a-zA-Z0-9_-]+", skill_name):
raise ValueError(f"Invalid skill name: {skill_name}")
target = custom_dir / skill_name
if target.exists():
raise ValueError(f"Skill '{skill_name}' already exists")
shutil.copytree(skill_dir, target)
return {"success": True, "skill_name": skill_name, "message": f"Skill '{skill_name}' installed successfully"}
# ------------------------------------------------------------------
# Public API — memory management
# ------------------------------------------------------------------
def reload_memory(self) -> dict:
"""Reload memory data from file, forcing cache invalidation.
Returns:
The reloaded memory data dict.
"""
from src.agents.memory.updater import reload_memory_data
return reload_memory_data()
def get_memory_config(self) -> dict:
"""Get memory system configuration.
Returns:
Memory config dict.
"""
from src.config.memory_config import get_memory_config
config = get_memory_config()
return {
"enabled": config.enabled,
"storage_path": config.storage_path,
"debounce_seconds": config.debounce_seconds,
"max_facts": config.max_facts,
"fact_confidence_threshold": config.fact_confidence_threshold,
"injection_enabled": config.injection_enabled,
"max_injection_tokens": config.max_injection_tokens,
}
def get_memory_status(self) -> dict:
"""Get memory status: config + current data.
Returns:
Dict with "config" and "data" keys.
"""
return {
"config": self.get_memory_config(),
"data": self.get_memory(),
}
# ------------------------------------------------------------------
# Public API — file uploads
# ------------------------------------------------------------------
@staticmethod
def _get_uploads_dir(thread_id: str) -> Path:
"""Get (and create) the uploads directory for a thread."""
base = get_paths().sandbox_uploads_dir(thread_id)
base.mkdir(parents=True, exist_ok=True)
return base
def upload_files(self, thread_id: str, files: list[str | Path]) -> list[dict]:
"""Upload local files into a thread's uploads directory.
For PDF, PPT, Excel, and Word files, they are also converted to Markdown.
Args:
thread_id: Target thread ID.
files: List of local file paths to upload.
Returns:
List of file info dicts (filename, size, path, virtual_path).
Raises:
FileNotFoundError: If any file does not exist.
"""
from src.gateway.routers.uploads import CONVERTIBLE_EXTENSIONS, convert_file_to_markdown
# Validate all files upfront to avoid partial uploads.
resolved_files = []
for f in files:
p = Path(f)
if not p.exists():
raise FileNotFoundError(f"File not found: {f}")
resolved_files.append(p)
uploads_dir = self._get_uploads_dir(thread_id)
results: list[dict] = []
for src_path in resolved_files:
dest = uploads_dir / src_path.name
shutil.copy2(src_path, dest)
info: dict[str, Any] = {
"filename": src_path.name,
"size": dest.stat().st_size,
"path": str(dest),
"virtual_path": f"/mnt/user-data/uploads/{src_path.name}",
}
if src_path.suffix.lower() in CONVERTIBLE_EXTENSIONS:
try:
try:
asyncio.get_running_loop()
import concurrent.futures
with concurrent.futures.ThreadPoolExecutor() as pool:
md_path = pool.submit(lambda: asyncio.run(convert_file_to_markdown(dest))).result()
except RuntimeError:
md_path = asyncio.run(convert_file_to_markdown(dest))
except Exception:
logger.warning("Failed to convert %s to markdown", src_path.name, exc_info=True)
md_path = None
if md_path is not None:
info["markdown_file"] = md_path.name
info["markdown_virtual_path"] = f"/mnt/user-data/uploads/{md_path.name}"
results.append(info)
return results
def list_uploads(self, thread_id: str) -> list[dict]:
"""List files in a thread's uploads directory.
Args:
thread_id: Thread ID.
Returns:
List of file info dicts.
"""
uploads_dir = self._get_uploads_dir(thread_id)
if not uploads_dir.exists():
return []
files = []
for fp in sorted(uploads_dir.iterdir()):
if fp.is_file():
stat = fp.stat()
files.append({
"filename": fp.name,
"size": stat.st_size,
"path": str(fp),
"virtual_path": f"/mnt/user-data/uploads/{fp.name}",
"extension": fp.suffix,
"modified": stat.st_mtime,
})
return files
def delete_upload(self, thread_id: str, filename: str) -> None:
"""Delete a file from a thread's uploads directory.
Args:
thread_id: Thread ID.
filename: Filename to delete.
Raises:
FileNotFoundError: If the file does not exist.
PermissionError: If path traversal is detected.
"""
uploads_dir = self._get_uploads_dir(thread_id)
file_path = (uploads_dir / filename).resolve()
try:
file_path.relative_to(uploads_dir.resolve())
except ValueError:
raise PermissionError("Access denied: path traversal detected")
if not file_path.is_file():
raise FileNotFoundError(f"File not found: {filename}")
file_path.unlink()
# ------------------------------------------------------------------
# Public API — artifacts
# ------------------------------------------------------------------
def get_artifact(self, thread_id: str, path: str) -> tuple[bytes, str]:
"""Read an artifact file produced by the agent.
Args:
thread_id: Thread ID.
path: Virtual path (e.g. "mnt/user-data/outputs/file.txt").
Returns:
Tuple of (file_bytes, mime_type).
Raises:
FileNotFoundError: If the artifact does not exist.
ValueError: If the path is invalid.
"""
virtual_prefix = "mnt/user-data"
clean_path = path.lstrip("/")
if not clean_path.startswith(virtual_prefix):
raise ValueError(f"Path must start with /{virtual_prefix}")
relative = clean_path[len(virtual_prefix):].lstrip("/")
base_dir = get_paths().sandbox_user_data_dir(thread_id)
actual = (base_dir / relative).resolve()
try:
actual.relative_to(base_dir.resolve())
except ValueError:
raise PermissionError("Access denied: path traversal detected")
if not actual.exists():
raise FileNotFoundError(f"Artifact not found: {path}")
if not actual.is_file():
raise ValueError(f"Path is not a file: {path}")
mime_type, _ = mimetypes.guess_type(actual)
return actual.read_bytes(), mime_type or "application/octet-stream"