feat: add new headers dependency to routes (#2903)

fern/scripts/prepare-openapi.ts

@@ -98,7 +98,7 @@ for (const path of Object.keys(lettaAgentsAPI.paths)) {
       ][method].parameters.filter(
         (param: Record<string, string>) =>
           param.in !== 'header' ||
-          (param.name !== 'user_id' && param.name !== 'actor_id'),
+          (param.name !== 'user_id' && param.name !== 'User-Agent' && param.name !== 'X-Project-Id'),
       );
     }
   }

letta/server/rest_api/dependencies/headers.py

@@ -0,0 +1,25 @@
+from typing import Optional
+
+from fastapi import Header
+from pydantic import BaseModel
+
+
+class HeaderParams(BaseModel):
+    """Common header parameters used across REST API endpoints."""
+
+    actor_id: Optional[str] = None
+    user_agent: Optional[str] = None
+    project_id: Optional[str] = None
+
+
+def get_headers(
+    actor_id: Optional[str] = Header(None, alias="user_id"),
+    user_agent: Optional[str] = Header(None, alias="User-Agent"),
+    project_id: Optional[str] = Header(None, alias="X-Project-Id"),
+) -> HeaderParams:
+    """Dependency injection function to extract common headers from requests."""
+    return HeaderParams(
+        actor_id=actor_id,
+        user_agent=user_agent,
+        project_id=project_id,
+    )