Initial commit: fastapi-traffic rate limiting library

- Core rate limiting with multiple algorithms (sliding window, token bucket, etc.)
- SQLite and memory backends
- Decorator and dependency injection patterns
- Middleware support
- Example usage files

examples/01_quickstart.py

@@ -0,0 +1,60 @@
+"""Quickstart example - minimal setup to get rate limiting working."""
+
+from __future__ import annotations
+
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI, Request
+from fastapi.responses import JSONResponse
+
+from fastapi_traffic import (
+    MemoryBackend,
+    RateLimitExceeded,
+    RateLimiter,
+    rate_limit,
+)
+from fastapi_traffic.core.limiter import set_limiter
+
+# Step 1: Create a backend and limiter
+backend = MemoryBackend()
+limiter = RateLimiter(backend)
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Lifespan context manager for startup/shutdown."""
+    await limiter.initialize()
+    set_limiter(limiter)
+    yield
+    await limiter.close()
+
+
+app = FastAPI(title="Quickstart Example", lifespan=lifespan)
+
+
+# Step 2: Add exception handler for rate limit errors
+@app.exception_handler(RateLimitExceeded)
+async def rate_limit_handler(request: Request, exc: RateLimitExceeded) -> JSONResponse:
+    return JSONResponse(
+        status_code=429,
+        content={"error": "Too many requests", "retry_after": exc.retry_after},
+    )
+
+
+# Step 3: Apply rate limiting to endpoints
+@app.get("/")
+@rate_limit(10, 60)  # 10 requests per minute
+async def hello(request: Request) -> dict[str, str]:
+    return {"message": "Hello, World!"}
+
+
+@app.get("/api/data")
+@rate_limit(100, 60)  # 100 requests per minute
+async def get_data(request: Request) -> dict[str, str]:
+    return {"data": "Some important data"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000)