Bind chat agent sessions to individual devices

apps/device-host-agent/host_agent/conversation.py

@@ -40,12 +40,13 @@ class ConversationAgent:
         self.event_logger = event_logger
         self._client: Any | None = None
 
-    def chat(self, messages: list[dict[str, Any]]) -> ChatResult:
+    def chat(self, messages: list[dict[str, Any]], *, tools: dict[str, Callable[..., Any]] | None = None) -> ChatResult:
         if self.config.provider not in {"openai", "openai_compatible"}:
             raise RuntimeError(
                 "conversation chat currently requires an OpenAI-compatible provider"
             )
         client = self._get_client()
+        active_tools = tools or self.tools
         history: list[dict[str, Any]] = [
             {
                 "role": "system",
@@ -88,7 +89,7 @@ class ConversationAgent:
                     arguments = decoded_arguments
                     arguments.pop("purpose", None)
                     arguments.pop("expected_outcome", None)
-                    result = self.tools[name](**arguments)
+                    result = active_tools[name](**arguments)
                 except Exception as exc:
                     result = {"ok": False, "error": str(exc)}
                 calls += 1
@@ -103,6 +104,14 @@ class ConversationAgent:
                 )
         raise RuntimeError("conversation exceeded the maximum tool-call rounds")
 
+    def chat_for_device(self, device_id: str, messages: list[dict[str, Any]]) -> ChatResult:
+        """Run a conversation bound to exactly one device."""
+        device_tools = {
+            name: _bind_device(tool, device_id, name=name)
+            for name, tool in original_tools.items()
+        }
+        return self.chat(messages, tools=device_tools)
+
     def _log(self, event: dict[str, Any]) -> None:
         if self.event_logger is not None:
             try:
@@ -192,3 +201,16 @@ def _normalize_message(message: dict[str, Any]) -> dict[str, Any]:
         blocks.append({"type": "image_url", "image_url": {"url": f"data:{mime};base64,{image}"}})
         return {"role": role, "content": blocks}
     raise ValueError("message content must be text, image blocks, or image_base64")
+
+
+def _bind_device(tool: Callable[..., Any], device_id: str, *, name: str) -> Callable[..., Any]:
+    def bound(**arguments: Any) -> Any:
+        if name == "list_devices":
+            return tool(**arguments)
+        requested = arguments.get("device_id")
+        if requested is not None and requested != device_id:
+            raise ValueError(f"conversation is bound to device {device_id}")
+        arguments["device_id"] = device_id
+        return tool(**arguments)
+
+    return bound