Improve schema

core/session.py

@@ -107,8 +107,6 @@ class Session:
         # Track IDs
         self.current_track_id: str = self.TRACK_CONTROL
         self._event_seq: int = 0
-        self._audio_ingress_buffer: bytes = b""
-        self._audio_frame_error_reported: bool = False
         self._history_call_id: Optional[str] = None
         self._history_turn_index: int = 0
         self._history_call_started_mono: Optional[float] = None
@@ -179,23 +177,18 @@ class Session:
                 return
 
             frame_bytes = self.AUDIO_FRAME_BYTES
-            self._audio_ingress_buffer += audio_bytes
-
-            # Protocol v1 audio framing: 20ms PCM frame (640 bytes).
-            # Allow aggregated frames in one WS message (multiple of 640).
-            if len(audio_bytes) % frame_bytes != 0 and not self._audio_frame_error_reported:
-                self._audio_frame_error_reported = True
+            if len(audio_bytes) % frame_bytes != 0:
                 await self._send_error(
                     "client",
-                    f"Audio frame size should be multiple of {frame_bytes} bytes (20ms PCM)",
+                    f"Audio frame size must be a multiple of {frame_bytes} bytes (20ms PCM)",
                     "audio.frame_size_mismatch",
                     stage="audio",
-                    retryable=True,
+                    retryable=False,
                 )
+                return
 
-            while len(self._audio_ingress_buffer) >= frame_bytes:
-                frame = self._audio_ingress_buffer[:frame_bytes]
-                self._audio_ingress_buffer = self._audio_ingress_buffer[frame_bytes:]
+            for i in range(0, len(audio_bytes), frame_bytes):
+                frame = audio_bytes[i : i + frame_bytes]
                 await self.pipeline.process_audio(frame)
         except Exception as e:
             logger.error(f"Session {self.id} handle_audio error: {e}", exc_info=True)
@@ -246,7 +239,7 @@ class Session:
             else:
                 await self.pipeline.interrupt()
         elif isinstance(message, ToolCallResultsMessage):
-            await self.pipeline.handle_tool_call_results(message.results)
+            await self.pipeline.handle_tool_call_results([item.model_dump() for item in message.results])
         elif isinstance(message, SessionStopMessage):
             await self._handle_session_stop(message.reason)
         else:
@@ -268,9 +261,9 @@ class Session:
             self.ws_state = WsSessionState.STOPPED
             return
 
-        auth_payload = message.auth or {}
-        api_key = auth_payload.get("apiKey")
-        jwt = auth_payload.get("jwt")
+        auth_payload = message.auth
+        api_key = auth_payload.apiKey if auth_payload else None
+        jwt = auth_payload.jwt if auth_payload else None
 
         if settings.ws_api_key:
             if api_key != settings.ws_api_key:
@@ -330,7 +323,7 @@ class Session:
                     "audio_out": self.TRACK_AUDIO_OUT,
                     "control": self.TRACK_CONTROL,
                 },
-                audio=message.audio or {},
+                audio=message.audio.model_dump() if message.audio else {},
             )
         )
         await self._send_event(
@@ -383,6 +376,7 @@ class Session:
         code: str,
         stage: Optional[str] = None,
         retryable: Optional[bool] = None,
+        track_id: Optional[str] = None,
     ) -> None:
         """
         Send error event to client.
@@ -394,6 +388,7 @@ class Session:
         """
         resolved_stage = stage or self._infer_error_stage(code)
         resolved_retryable = retryable if retryable is not None else (resolved_stage in {"asr", "llm", "tts", "tool", "audio"})
+        resolved_track_id = track_id or self._error_track_id(resolved_stage, code)
         await self._send_event(
             ev(
                 "error",
@@ -402,7 +397,7 @@ class Session:
                 message=error_message,
                 stage=resolved_stage,
                 retryable=resolved_retryable,
-                trackId=self.current_track_id,
+                trackId=resolved_track_id,
                 data={
                     "error": {
                         "stage": resolved_stage,
@@ -666,6 +661,15 @@ class Session:
             return "tts"
         return "protocol"
 
+    def _error_track_id(self, stage: str, code: str) -> str:
+        if stage in {"audio", "asr"}:
+            return self.TRACK_AUDIO_IN
+        if stage in {"llm", "tts", "tool"}:
+            return self.TRACK_AUDIO_OUT
+        if str(code or "").strip().lower().startswith("auth."):
+            return self.TRACK_CONTROL
+        return self.TRACK_CONTROL
+
     def _envelope_event(self, event: Dict[str, Any]) -> Dict[str, Any]:
         event_type = str(event.get("type") or "")
         source = str(event.get("source") or self._event_source(event_type))

docs/ws_v1_schema.md

@@ -2,6 +2,11 @@
 
 This document defines the public WebSocket protocol for the `/ws` endpoint.
 
+Validation policy:
+- WS v1 JSON control messages are validated strictly.
+- Unknown top-level fields are rejected for all defined client message types.
+- `hello.version` is fixed to `"v1"`.
+
 ## Transport
 
 - A single WebSocket connection carries:
@@ -138,7 +143,8 @@ All server events include an envelope:
 
 Envelope notes:
 - `seq` is monotonically increasing within one session (for replay/resume).
-- `source` is one of: `asr | llm | tts | tool | system`.
+- `source` is one of: `asr | llm | tts | tool | system | client | server`.
+  - For `assistant.tool_result`, `source` may be `client` or `server` to indicate execution side.
 - `data` is structured payload; legacy top-level fields are kept for compatibility.
 
 Common events:
@@ -181,6 +187,10 @@ Common events:
   - Fields: `trackId`, `latencyMs`
 - `error`
   - Fields: `sender`, `code`, `message`, `trackId`
+  - `trackId` convention:
+    - `audio_in` for `stage in {audio, asr}`
+    - `audio_out` for `stage in {llm, tts, tool}`
+    - `control` otherwise (including protocol/auth errors)
 
 Track IDs (MVP fixed values):
 - `audio_in`: ASR/VAD input-side events (`input.*`, `transcript.*`)
@@ -207,7 +217,7 @@ MVP fixed format:
 Framing rules:
 - Binary audio frame unit is 640 bytes.
 - A WS binary message may carry one or multiple complete 640-byte frames.
-- Non-640-multiple payloads are treated as `audio.frame_size_mismatch` protocol errors.
+- Non-640-multiple payloads are rejected as `audio.frame_size_mismatch`; that WS message is dropped (no partial buffering/reassembly).
 
 TTS boundary events:
 - `output.audio.start` and `output.audio.end` mark assistant playback boundaries.

models/ws_v1.py

@@ -1,7 +1,8 @@
 """WS v1 protocol message models and helpers."""
 
-from typing import Optional, Dict, Any, Literal
-from pydantic import BaseModel, Field
+from typing import Any, Dict, Literal, Optional
+
+from pydantic import BaseModel, ConfigDict, Field, ValidationError
 
 
 def now_ms() -> int:
@@ -11,37 +12,66 @@ def now_ms() -> int:
     return int(time.time() * 1000)
 
 
+class _StrictModel(BaseModel):
+    """Protocol models reject unknown fields to enforce WS v1 schema."""
+
+    model_config = ConfigDict(extra="forbid")
+
+
 # Client -> Server messages
-class HelloMessage(BaseModel):
+class HelloAuth(_StrictModel):
+    apiKey: Optional[str] = None
+    jwt: Optional[str] = None
+
+
+class HelloMessage(_StrictModel):
     type: Literal["hello"]
-    version: str = Field(..., description="Protocol version, currently v1")
-    auth: Optional[Dict[str, str]] = Field(default=None, description="Auth payload, e.g. {'apiKey': '...'}")
+    version: Literal["v1"] = Field(..., description="Protocol version, fixed to v1")
+    auth: Optional[HelloAuth] = Field(default=None, description="Auth payload")
 
 
-class SessionStartMessage(BaseModel):
+class SessionStartAudio(_StrictModel):
+    encoding: Literal["pcm_s16le"] = "pcm_s16le"
+    sample_rate_hz: Literal[16000] = 16000
+    channels: Literal[1] = 1
+
+
+class SessionStartMessage(_StrictModel):
     type: Literal["session.start"]
-    audio: Optional[Dict[str, Any]] = Field(default=None, description="Optional audio format metadata")
+    audio: Optional[SessionStartAudio] = Field(default=None, description="Optional audio format metadata")
     metadata: Optional[Dict[str, Any]] = Field(default=None, description="Optional session metadata")
 
 
-class SessionStopMessage(BaseModel):
+class SessionStopMessage(_StrictModel):
     type: Literal["session.stop"]
     reason: Optional[str] = None
 
 
-class InputTextMessage(BaseModel):
+class InputTextMessage(_StrictModel):
     type: Literal["input.text"]
     text: str
 
 
-class ResponseCancelMessage(BaseModel):
+class ResponseCancelMessage(_StrictModel):
     type: Literal["response.cancel"]
     graceful: bool = False
 
 
-class ToolCallResultsMessage(BaseModel):
+class ToolCallResultStatus(_StrictModel):
+    code: int
+    message: str
+
+
+class ToolCallResult(_StrictModel):
+    tool_call_id: str
+    name: str
+    output: Any = None
+    status: ToolCallResultStatus
+
+
+class ToolCallResultsMessage(_StrictModel):
     type: Literal["tool_call.results"]
-    results: list[Dict[str, Any]] = Field(default_factory=list)
+    results: list[ToolCallResult] = Field(default_factory=list)
 
 
 CLIENT_MESSAGE_TYPES = {
@@ -62,7 +92,15 @@ def parse_client_message(data: Dict[str, Any]) -> BaseModel:
     msg_class = CLIENT_MESSAGE_TYPES.get(msg_type)
     if not msg_class:
         raise ValueError(f"Unknown client message type: {msg_type}")
-    return msg_class(**data)
+    try:
+        return msg_class(**data)
+    except ValidationError as exc:
+        details = []
+        for err in exc.errors():
+            loc = ".".join(str(part) for part in err.get("loc", ()))
+            msg = err.get("msg", "invalid field")
+            details.append(f"{loc}: {msg}" if loc else msg)
+        raise ValueError("; ".join(details)) from exc
 
 
 # Server -> Client event helpers

tests/test_tool_call_flow.py

@@ -97,11 +97,11 @@ async def test_ws_message_parses_tool_call_results():
     msg = parse_client_message(
         {
             "type": "tool_call.results",
-            "results": [{"tool_call_id": "call_1", "status": {"code": 200, "message": "ok"}}],
+            "results": [{"tool_call_id": "call_1", "name": "weather", "status": {"code": 200, "message": "ok"}}],
         }
     )
     assert isinstance(msg, ToolCallResultsMessage)
-    assert msg.results[0]["tool_call_id"] == "call_1"
+    assert msg.results[0].tool_call_id == "call_1"
 
 
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