[ FastAPI ] Add request ID middleware for log correlation

[dacdoyx]

Summary

Implements #797 - Add request ID middleware to FastAPI.

Changes

1. **New file: **

   • class extending
   • Reads header or generates a UUID
   • Stores request ID in
   • Sets request ID in ContextVar for access in loggers
   • Adds response header
   • Properly cleans up ContextVar after request

2. **Updated: **

   • Added logging filter that injects into log records
   • Configured formatter with placeholder for log correlation

3. **Updated: **

   • Exports and for public API

Usage

from fastapi import FastAPI
from fastapi.middleware import RequestIDMiddleware

app = FastAPI()
app.add_middleware(RequestIDMiddleware)

All log messages from the logger will now include the request ID:

2026-06-26 04:30:00 INFO [abc123def456] fastapi: Request processed

Closes #797

[github-actions]

Unfortunately the changes in this PR didn't fully resolve the issue. Please rework your solution and submit a new pull request.

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