Files
livekit_agents/hermes_gateway.py
2026-06-01 16:50:00 +08:00

392 lines
12 KiB
Python

from __future__ import annotations
import json
from collections.abc import AsyncIterator
from dataclasses import dataclass
from typing import Any
import aiohttp
from livekit.agents import llm
from livekit.agents._exceptions import APIConnectionError
from livekit.agents.types import (
DEFAULT_API_CONNECT_OPTIONS,
NOT_GIVEN,
APIConnectOptions,
NotGivenOr,
)
from livekit.agents.utils import shortuuid
@dataclass
class GatewaySessionState:
room_name: str
agent_id: str | None = None
session_key: str | None = None
session_mode: str = "per_room"
def __post_init__(self) -> None:
if self.session_mode != "per_room":
raise ValueError("Hermes gateway only supports CUSTOM_HERMES_SESSION_MODE=per_room")
if self.session_key is None:
suffix = self.agent_id or "default"
self.session_key = f"livekit:{self.room_name}:{suffix}"
class HermesGatewayLLM(llm.LLM):
def __init__(
self,
*,
url: str,
token: str | None,
state: GatewaySessionState,
agent_id: str | None = None,
model_name: str = "hermes-agent",
request_timeout: float = 30.0,
) -> None:
super().__init__()
self._url = url
self._token = token
self._state = state
self._agent_id = agent_id
self._model_name = model_name
self._request_timeout = request_timeout
self._http_session: aiohttp.ClientSession | None = None
@property
def model(self) -> str:
return self._model_name
@property
def provider(self) -> str:
return "hermes-gateway"
def chat(
self,
*,
chat_ctx: llm.ChatContext,
tools: list[llm.Tool] | None = None,
conn_options: APIConnectOptions = DEFAULT_API_CONNECT_OPTIONS,
parallel_tool_calls: NotGivenOr[bool] = NOT_GIVEN,
tool_choice: NotGivenOr[llm.ToolChoice] = NOT_GIVEN,
extra_kwargs: NotGivenOr[dict[str, Any]] = NOT_GIVEN,
) -> llm.LLMStream:
return HermesGatewayLLMStream(
self,
chat_ctx=chat_ctx,
tools=tools or [],
conn_options=conn_options,
)
def _ensure_http_session(self) -> aiohttp.ClientSession:
if self._http_session is None:
timeout = aiohttp.ClientTimeout(total=self._request_timeout)
self._http_session = aiohttp.ClientSession(timeout=timeout)
return self._http_session
async def aclose(self) -> None:
if self._http_session is not None:
await self._http_session.close()
self._http_session = None
class HermesGatewayLLMStream(llm.LLMStream):
def __init__(
self,
llm: HermesGatewayLLM,
*,
chat_ctx: llm.ChatContext,
tools: list[llm.Tool],
conn_options: APIConnectOptions,
) -> None:
super().__init__(llm, chat_ctx=chat_ctx, tools=tools, conn_options=conn_options)
self._llm = llm
async def _run(self) -> None:
request_id = shortuuid("gwreq_")
async with self._llm._ensure_http_session().ws_connect(self._llm._url) as ws:
await _connect(ws, token=self._llm._token)
await _send_rpc(
ws,
method="sessions.create",
params={
"key": self._llm._state.session_key,
"sessionKey": self._llm._state.session_key,
"agentId": self._llm._agent_id,
"metadata": {
"source": "livekit",
"room": self._llm._state.room_name,
},
"idempotencyKey": self._llm._state.session_key,
},
request_id=shortuuid("gwcreate_"),
)
await _send_rpc(
ws,
method="sessions.send",
params={
"key": self._llm._state.session_key,
"sessionKey": self._llm._state.session_key,
"agentId": self._llm._agent_id,
"messages": chat_context_to_gateway_messages(self.chat_ctx),
"stream": True,
"idempotencyKey": request_id,
},
request_id=request_id,
wait_response=False,
)
streamed_text = ""
async for frame in _iter_gateway_frames(ws):
if is_error_response(frame, request_id=request_id):
raise APIConnectionError(_gateway_error_message(frame), retryable=False)
text = extract_text_delta(frame)
if text:
if text.startswith(streamed_text):
text = text[len(streamed_text) :]
if text:
streamed_text += text
self._event_ch.send_nowait(
llm.ChatChunk(
id=request_id,
delta=llm.ChoiceDelta(role="assistant", content=text),
)
)
if is_terminal_event(frame, request_id=request_id):
return
def build_connect_params(*, token: str | None) -> dict[str, Any]:
params: dict[str, Any] = {
"minProtocol": 3,
"maxProtocol": 4,
"client": {
"id": "gateway-client",
"version": "livekit-custom-agent",
"platform": "python",
"mode": "backend",
},
"role": "operator",
"scopes": ["operator.read", "operator.write"],
"caps": [],
"commands": [],
"permissions": {},
"locale": "zh-CN",
"userAgent": "livekit-custom-agent",
}
if token:
params["auth"] = {"token": token}
return params
def chat_context_to_gateway_messages(chat_ctx: llm.ChatContext) -> list[dict[str, Any]]:
messages: list[dict[str, Any]] = []
for message in chat_ctx.messages():
content = _message_content_to_gateway_content(message.content)
if content is None:
continue
messages.append({"role": message.role, "content": content})
return messages
def extract_text_delta(frame: dict[str, Any]) -> str:
payload = frame.get("payload")
if not isinstance(payload, dict):
payload = frame
for path in (
("delta", "content"),
("delta", "text"),
("message", "delta", "content"),
("message", "delta", "text"),
("message", "content"),
("content",),
("text",),
):
value = _get_nested(payload, path)
text = _content_to_text(value)
if text:
return text
return ""
def is_terminal_event(frame: dict[str, Any], *, request_id: str) -> bool:
if frame.get("type") == "res" and frame.get("id") == request_id:
return True
event = frame.get("event")
if event in {
"agent.done",
"agent.completed",
"agent.error",
"session.message.completed",
"session.run.completed",
"sessions.run.completed",
"run.completed",
"run.failed",
}:
return True
payload = frame.get("payload")
if isinstance(payload, dict) and payload.get("done") is True:
return True
return False
def is_error_response(frame: dict[str, Any], *, request_id: str) -> bool:
if (
frame.get("type") == "res"
and frame.get("id") == request_id
and frame.get("ok") is False
):
return True
return frame.get("event") in {
"agent.error",
"session.error",
"session.run.failed",
"sessions.run.failed",
"run.failed",
}
def _gateway_error_message(frame: dict[str, Any]) -> str:
error = frame.get("error")
if isinstance(error, str):
return f"OpenClaw gateway request failed: {error}"
if isinstance(error, dict):
message = error.get("message") or error.get("error")
if isinstance(message, str):
return f"OpenClaw gateway request failed: {message}"
payload = frame.get("payload")
if isinstance(payload, dict):
message = payload.get("message") or payload.get("error")
if isinstance(message, str):
return f"OpenClaw gateway request failed: {message}"
return f"OpenClaw gateway request failed: {frame!r}"
async def _connect(ws: aiohttp.ClientWebSocketResponse, *, token: str | None) -> None:
first = await _receive_json(ws)
if first.get("event") != "connect.challenge":
raise RuntimeError(f"expected connect.challenge, received {first!r}")
request_id = shortuuid("gwconnect_")
await _send_rpc(
ws,
method="connect",
params=build_connect_params(token=token),
request_id=request_id,
wait_response=False,
)
response = await _wait_for_response(ws, request_id=request_id)
if not response.get("ok"):
raise RuntimeError(f"OpenClaw gateway connect failed: {response.get('error')!r}")
async def _send_rpc(
ws: aiohttp.ClientWebSocketResponse,
*,
method: str,
params: dict[str, Any],
request_id: str,
wait_response: bool = True,
) -> dict[str, Any] | None:
await ws.send_str(
json.dumps(
{
"type": "req",
"id": request_id,
"method": method,
"params": _drop_none(params),
}
)
)
if not wait_response:
return None
response = await _wait_for_response(ws, request_id=request_id)
if not response.get("ok", False):
raise RuntimeError(f"OpenClaw gateway RPC {method} failed: {response.get('error')!r}")
return response
async def _wait_for_response(
ws: aiohttp.ClientWebSocketResponse, *, request_id: str
) -> dict[str, Any]:
async for frame in _iter_gateway_frames(ws):
if frame.get("type") == "res" and frame.get("id") == request_id:
return frame
raise RuntimeError(f"OpenClaw gateway closed before response {request_id}")
async def _iter_gateway_frames(
ws: aiohttp.ClientWebSocketResponse,
) -> AsyncIterator[dict[str, Any]]:
async for message in ws:
if message.type == aiohttp.WSMsgType.TEXT:
yield json.loads(message.data)
elif message.type in (aiohttp.WSMsgType.CLOSED, aiohttp.WSMsgType.CLOSE):
return
elif message.type == aiohttp.WSMsgType.ERROR:
raise RuntimeError(f"OpenClaw gateway websocket error: {ws.exception()!r}")
async def _receive_json(ws: aiohttp.ClientWebSocketResponse) -> dict[str, Any]:
message = await ws.receive()
if message.type != aiohttp.WSMsgType.TEXT:
raise RuntimeError(f"expected gateway text frame, received {message.type!r}")
return json.loads(message.data)
def _message_content_to_gateway_content(content: list[llm.ChatContent]) -> Any:
parts: list[dict[str, Any]] = []
for item in content:
if isinstance(item, str):
if item:
parts.append({"type": "text", "text": item})
elif isinstance(item, llm.ImageContent) and isinstance(item.image, str):
parts.append({"type": "image_url", "image_url": {"url": item.image}})
if not parts:
return None
if len(parts) == 1 and parts[0]["type"] == "text":
return parts[0]["text"]
return parts
def _content_to_text(value: Any) -> str:
if isinstance(value, str):
return value
if isinstance(value, list):
text_parts: list[str] = []
for item in value:
if isinstance(item, str):
text_parts.append(item)
elif isinstance(item, dict):
text = item.get("text")
if isinstance(text, str):
text_parts.append(text)
return "".join(text_parts)
return ""
def _get_nested(data: dict[str, Any], path: tuple[str, ...]) -> Any:
current: Any = data
for key in path:
if not isinstance(current, dict):
return None
current = current.get(key)
return current
def _drop_none(value: Any) -> Any:
if isinstance(value, dict):
return {key: _drop_none(item) for key, item in value.items() if item is not None}
if isinstance(value, list):
return [_drop_none(item) for item in value]
return value