Huge v2 uplift, now deployable with real user management and tooling!

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/middleware/request_id.py

@@ -0,0 +1,93 @@
+"""
+Request ID middleware for request tracing.
+
+Generates or propagates X-Request-ID header for distributed tracing.
+"""
+
+import logging
+import uuid
+from typing import Optional
+
+from fastapi import Request
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.responses import Response
+
+from logging_config import request_id_var
+
+logger = logging.getLogger(__name__)
+
+
+class RequestIDMiddleware(BaseHTTPMiddleware):
+    """
+    HTTP middleware for request ID generation and propagation.
+
+    - Extracts X-Request-ID from incoming request headers
+    - Generates a new UUID if not present
+    - Sets request_id in context var for logging
+    - Adds X-Request-ID to response headers
+    """
+
+    def __init__(
+        self,
+        app,
+        header_name: str = "X-Request-ID",
+        generator: Optional[callable] = None,
+    ):
+        """
+        Initialize request ID middleware.
+
+        Args:
+            app: FastAPI application.
+            header_name: Header name for request ID.
+            generator: Optional custom ID generator function.
+        """
+        super().__init__(app)
+        self.header_name = header_name
+        self.generator = generator or (lambda: str(uuid.uuid4()))
+
+    async def dispatch(self, request: Request, call_next) -> Response:
+        """
+        Process request with request ID.
+
+        Args:
+            request: Incoming HTTP request.
+            call_next: Next middleware/handler in chain.
+
+        Returns:
+            HTTP response with X-Request-ID header.
+        """
+        # Get or generate request ID
+        request_id = request.headers.get(self.header_name)
+        if not request_id:
+            request_id = self.generator()
+
+        # Set in request state for access in handlers
+        request.state.request_id = request_id
+
+        # Set in context var for logging
+        token = request_id_var.set(request_id)
+
+        try:
+            # Process request
+            response = await call_next(request)
+
+            # Add request ID to response
+            response.headers[self.header_name] = request_id
+
+            return response
+        finally:
+            # Reset context var
+            request_id_var.reset(token)
+
+
+def get_request_id(request: Request) -> Optional[str]:
+    """
+    Get request ID from request state.
+
+    Args:
+        request: FastAPI request object.
+
+    Returns:
+        Request ID string or None.
+    """
+    return getattr(request.state, "request_id", None)