🧑‍💻 Usage Guide

FastAPI Cachekit makes it easy to cache results in your FastAPI app using decorators or dependency injection.
Below are the most common usage patterns.

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1️⃣ Decorator for Functions

You can use the @cache.cached() decorator to cache the result of any function (sync or async), not just FastAPI routes.

from fast_cache import FastAPICache, InMemoryBackend

cache = FastAPICache()
backend = InMemoryBackend()
cache.init_app(app, backend)

@cache.cached(expire=60)
def expensive_computation(x: int):
    # This result will be cached for 60 seconds
    return x * 2

result = expensive_computation(10)  # Cached!

• Works for both sync and async functions.
• You can specify expire (in seconds or as a timedelta).

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2️⃣ Decorator for FastAPI Routes

You can use the same decorator directly on your FastAPI endpoints to cache their responses.

from fastapi import FastAPI
from fast_cache import FastAPICache, InMemoryBackend

app = FastAPI()
cache = FastAPICache()
backend = InMemoryBackend()
cache.init_app(app, backend)

@app.get("/expensive")
@cache.cached(expire=120)
async def expensive_route(x: int):
    # This endpoint's response will be cached for 2 minutes
    return {"result": x * 2}

• Works for both @app.get, @app.post, etc.
• Supports both sync and async endpoints.

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3️⃣ Dependency Injection for Advanced Use

For more control, you can inject the backend and use its methods directly (e.g., for custom cache keys, manual cache control, or advanced logic).

from fastapi import Depends
from fast_cache import cache, CacheBackend

## Add The cache init Here

@app.get("/profile/{user_id}")
async def get_profile(
    user_id: int,
    cache_backend: CacheBackend = Depends(cache.get_cache)
):
    key = f"profile:{user_id}"
    cached = await cache_backend.aget(key)
    if cached:
        return {"profile": cached, "cached": True}
    # Simulate expensive fetch
    profile = {"user_id": user_id, "bio": f"User {user_id} bio"}
    await cache_backend.aset(key, profile, expire=60)
    return {"profile": profile, "cached": False}

• Use Depends(cache.get_cache) to inject the backend.
• Use aget, aset, adelete, etc. for async; get, set, etc. for sync.

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🔗 Next Steps

• API Reference
• Backends

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FastAPI Cachekit makes caching easy, flexible, and production-ready!