feat: integrate volcengine tts functionality

src/server/app.py

@@ -1,19 +1,22 @@
 # Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
+import base64
 import json
 import logging
+import os
 from typing import List, cast
 from uuid import uuid4
 
-from fastapi import FastAPI
+from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
-from fastapi.responses import StreamingResponse
+from fastapi.responses import StreamingResponse, Response
 from langchain_core.messages import AIMessageChunk, ToolMessage
 from langgraph.types import Command
 
 from src.graph.builder import build_graph
-from src.server.chat_request import ChatMessage, ChatRequest
+from src.server.chat_request import ChatMessage, ChatRequest, TTSRequest
+from src.tools import VolcengineTTS
 
 logger = logging.getLogger(__name__)
 
@@ -137,3 +140,59 @@ def _make_event(event_type: str, data: dict[str, any]):
     if data.get("content") == "":
         data.pop("content")
     return f"event: {event_type}\ndata: {json.dumps(data, ensure_ascii=False)}\n\n"
+
+
+@app.post("/api/tts")
+async def text_to_speech(request: TTSRequest):
+    """Convert text to speech using volcengine TTS API."""
+    try:
+        app_id = os.getenv("VOLCENGINE_TTS_APPID", "")
+        if not app_id:
+            raise HTTPException(
+                status_code=400, detail="VOLCENGINE_TTS_APPID is not set"
+            )
+        access_token = os.getenv("VOLCENGINE_TTS_ACCESS_TOKEN", "")
+        if not access_token:
+            raise HTTPException(
+                status_code=400, detail="VOLCENGINE_TTS_ACCESS_TOKEN is not set"
+            )
+        cluster = os.getenv("VOLCENGINE_TTS_CLUSTER", "volcano_tts")
+        voice_type = os.getenv("VOLCENGINE_TTS_VOICE_TYPE", "BV700_V2_streaming")
+
+        tts_client = VolcengineTTS(
+            appid=app_id,
+            access_token=access_token,
+            cluster=cluster,
+            voice_type=voice_type,
+        )
+        # Call the TTS API
+        result = tts_client.text_to_speech(
+            text=request.text[:1024],
+            encoding=request.encoding,
+            speed_ratio=request.speed_ratio,
+            volume_ratio=request.volume_ratio,
+            pitch_ratio=request.pitch_ratio,
+            text_type=request.text_type,
+            with_frontend=request.with_frontend,
+            frontend_type=request.frontend_type,
+        )
+
+        if not result["success"]:
+            raise HTTPException(status_code=500, detail=str(result["error"]))
+
+        # Decode the base64 audio data
+        audio_data = base64.b64decode(result["audio_data"])
+
+        # Return the audio file
+        return Response(
+            content=audio_data,
+            media_type=f"audio/{request.encoding}",
+            headers={
+                "Content-Disposition": (
+                    f"attachment; filename=tts_output.{request.encoding}"
+                )
+            },
+        )
+    except Exception as e:
+        logger.exception(f"Error in TTS endpoint: {str(e)}")
+        raise HTTPException(status_code=500, detail=str(e))

src/server/chat_request.py

@@ -1,7 +1,7 @@
 # Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
-from typing import List, Optional, Union
+from typing import List, Optional, Union, Dict, Any
 
 from pydantic import BaseModel, Field
 
@@ -44,3 +44,19 @@ class ChatRequest(BaseModel):
     interrupt_feedback: Optional[str] = Field(
         None, description="Interrupt feedback from the user on the plan"
     )
+
+
+class TTSRequest(BaseModel):
+    text: str = Field(..., description="The text to convert to speech")
+    voice_type: Optional[str] = Field(
+        "BV700_V2_streaming", description="The voice type to use"
+    )
+    encoding: Optional[str] = Field("mp3", description="The audio encoding format")
+    speed_ratio: Optional[float] = Field(1.0, description="Speech speed ratio")
+    volume_ratio: Optional[float] = Field(1.0, description="Speech volume ratio")
+    pitch_ratio: Optional[float] = Field(1.0, description="Speech pitch ratio")
+    text_type: Optional[str] = Field("plain", description="Text type (plain or ssml)")
+    with_frontend: Optional[int] = Field(
+        1, description="Whether to use frontend processing"
+    )
+    frontend_type: Optional[str] = Field("unitTson", description="Frontend type")