fix: support photo client tool in debug preview

backend/routes/voice_webrtc.py

@@ -13,7 +13,7 @@ import json
 from collections.abc import Coroutine
 from typing import Any
 
-from fastapi import APIRouter, Body, Depends, Request, WebSocket
+from fastapi import APIRouter, Body, Depends, HTTPException, Request, WebSocket
 from loguru import logger
 from models import AssistantConfig, SignalingOffer
 from services.auth import require_admin, require_admin_websocket
@@ -35,6 +35,7 @@ _active_connections = realtime_lifecycle.active_connections
 _pipeline_tasks = realtime_lifecycle.pipeline_tasks
 _connection_tasks = realtime_lifecycle.connection_tasks
 PIPELINE_CLOSE_GRACE_SECONDS = 10.0
+MAX_CLIENT_TOOL_NAME_LENGTH = 64
 
 
 def _start_pipeline_task(
@@ -69,6 +70,53 @@ async def shutdown_active_sessions() -> None:
     )
 
 
+def _decode_client_tool_names(encoded: str | None) -> list[str] | None:
+    """Decode client capabilities carried outside the WebRTC SDP body.
+
+    Pipecat's browser transport replaces the body of a ``Request`` endpoint
+    with its SDP offer and drops ``APIRequest.requestData``. Request headers are
+    preserved, so they are the authoritative metadata channel for this path.
+    ``None`` means the header was absent and callers should use the legacy body.
+    """
+
+    if encoded is None:
+        return None
+    try:
+        padding = "=" * (-len(encoded) % 4)
+        value = json.loads(
+            base64.urlsafe_b64decode(encoded + padding).decode("utf-8")
+        )
+    except (ValueError, UnicodeDecodeError, json.JSONDecodeError) as exc:
+        raise HTTPException(
+            status_code=400,
+            detail="客户端工具能力请求头格式无效",
+        ) from exc
+    if not isinstance(value, list):
+        raise HTTPException(
+            status_code=400,
+            detail="客户端工具能力必须是函数名列表",
+        )
+
+    names: list[str] = []
+    seen: set[str] = set()
+    for item in value:
+        if not isinstance(item, str):
+            raise HTTPException(
+                status_code=400,
+                detail="客户端工具函数名必须是字符串",
+            )
+        name = item.strip()
+        if not name or len(name) > MAX_CLIENT_TOOL_NAME_LENGTH:
+            raise HTTPException(
+                status_code=400,
+                detail="客户端工具函数名为空或过长",
+            )
+        if name not in seen:
+            names.append(name)
+            seen.add(name)
+    return names
+
+
 @router.get("/api/webrtc/ice-servers", dependencies=[Depends(require_admin)])
 async def ice_servers():
     """Browser fetches STUN/TURN config (with ephemeral TURN creds when configured)."""
@@ -86,12 +134,22 @@ async def http_offer(request: Request, payload: dict = Body(...)):
         header_variables = json.loads(
             base64.urlsafe_b64decode(encoded_variables + padding).decode("utf-8")
         )
+    header_client_tools = _decode_client_tool_names(
+        request.headers.get("x-pipecat-client-tools")
+    )
+    client_tool_names = (
+        header_client_tools
+        if header_client_tools is not None
+        else request_data.get("client_tool_names") or []
+    )
+    logger.debug(f"WebRTC 客户端工具上报: {client_tool_names or '<none>'}")
     offer_payload = {
         **payload,
         "assistant_id": request.headers.get("x-pipecat-assistant-id"),
         "dynamic_variables": header_variables,
-        "client_tool_names": request_data.get("client_tool_names") or [],
         **request_data,
+        # Keep header metadata authoritative when both paths are present.
+        "client_tool_names": client_tool_names,
     }
     answer = await _handle_offer_payload(offer_payload, _http_peers)
     return answer