✨ Add route-level middleware decorator

This PR adds a new route_middleware decorator that allows attaching middleware logic directly to specific routes.

Features

• Route-specific middleware execution
• Supports sync & async middleware functions
• Clean decorator-based API
• Does not affect global middleware behavior

Added

• Core implementation in fastapi/route_middleware.py
• Full test coverage in tests/test_route_middleware.py
• Documentation example in docs_src/route_middleware/tutorial001.py

Why

FastAPI currently supports only application-level middleware. This feature enables fine-grained, per-route middleware use cases such as:

• Auth checks
• Logging
• Rate limiting
• Feature flags

All tests pass locally.

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing VashuTheGreat:feature/route-level-middleware (7cd6cb6) with master (a3dccae)¹}

Summary

✅ 20 untouched benchmarks

📝 Docs preview

Last commit 7cd6cb6 at: https://8ed98d8b.fastapitiangolo.pages.dev

✨ Add route-level middleware decorator

This PR adds a new route_middleware decorator that allows attaching middleware logic directly to specific routes.

Features

• Route-specific middleware execution
• Supports sync & async middleware functions
• Clean decorator-based API
• Does not affect global middleware behavior

Added

• Core implementation in fastapi/route_middleware.py
• Full test coverage in tests/test_route_middleware.py
• Documentation example in docs_src/route_middleware/tutorial001.py

Why

FastAPI currently supports only application-level middleware. This feature enables fine-grained, per-route middleware use cases such as:

• Auth checks
• Logging
• Rate limiting
• Feature flags

All tests pass locally.