v0.2.0 - Multi-Rate Policies & Selectors

🎉 FastAPI Pacer v0.2.0

This release introduces multi-rate policies, flexible selectors, and OpenTelemetry integration.

✨ New Features

Multi-Rate Policies

Apply multiple rate limits simultaneously - all rates must pass:

policy = Policy(
    rates=[
        Rate(1000, "1h"),  # Hourly limit
        Rate(100, "1m"),   # Minute limit  
        Rate(10, "1s"),    # Second limit
    ],
    key="api_key",
    name="tiered"
)

Flexible Selectors

• Built-in selectors: "ip", "api_key", "user", "org"
• Compose multiple selectors: compose(key_user, key_ip)
• Custom selector functions for any identity extraction

OpenTelemetry Integration

from pacer import create_otel_hooks

on_decision, on_error = create_otel_hooks("my-service")
limiter = Limiter(
    redis_url="redis://localhost:6379",
    on_decision=on_decision,
    on_error=on_error,
)

🔄 Breaking Changes

• Rate objects must now be wrapped in Policy objects
• Removed extractor parameter from Limiter - use Policy.key instead
• Removed backward compatibility RedisStorage class

🐛 Bug Fixes

• Fixed Lua script error when using multiple rates with padding
• Fixed Redis KEYS array handling for multi-rate evaluation
• Fixed burst capacity calculation (immediate requests = 1 + burst)

📚 Documentation

• Updated README with v0.2.0 examples
• Added comprehensive migration guide
• Expanded test coverage to 72+ tests

🏗️ Technical Improvements

• Full type safety with mypy clean
• Replaced deprecated FastAPI on_event with lifespan handlers
• Improved error handling for multi-rate policies
• Atomic multi-rate evaluation in single Redis RTT

📦 Dependencies

• FastAPI >= 0.100.0
• Redis >= 4.5.0
• Python >= 3.8

🙏 Acknowledgments

Thanks to all contributors and users for feedback and testing!

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Full Changelog: https://github.com/dan/fastapi-pacer/compare/v0.1.0...v0.2.0