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fastapi-memory

Caching, retry, and resilient-HTTP helpers for FastAPI services.

fastapi-memory consolidates the most common patterns for FastAPI services that talk to slower upstream APIs into one clean import:

  • Response caching — in-memory or Redis, with FmCacheManager.init()
  • Retry policies — exponential backoff, skip 4xx, with default_retry()
  • Cached singletons — @cached_singleton for config objects
  • Resilient HTTP client — persistent httpx.AsyncClient + retries + JSON helpers

Installation

pip install fastapi-memory

# with optional Redis cache backend support
pip install "fastapi-memory[redis]"

Quick import

Everything in fastapi-memory is accessible from one import:

from fastapi_memory import (
    FmCacheManager, FmMemoryBackend, memorize,
    retry, stop_after_retries, exponential_backoff, retry_on_error,
    fm_lru,
    default_retry, is_retryable_httpx_error,
    cached_singleton,
    FmResilientClient,
)

What's inside

Module Provides Helpers
caching FmCacheManager, FmMemoryBackend, memorize FmRedisBackend
resilience retry, stop_after_retries, exponential_backoff, etc. default_retry(), is_retryable_httpx_error()
config fm_lru cached_singleton
http — FmResilientClient

Quick examples

Caching

from fastapi import FastAPI
from fastapi_memory import FmCacheManager, FmMemoryBackend, memorize

FmCacheManager.init(FmMemoryBackend(), prefix="app-cache")

@memorize(expire=60)
async def get_data():
    ...

# Manual get/set
await FmCacheManager.set("my-key", {"data": "value"}, expire=60)
cached = await FmCacheManager.get("my-key")

@app.post("/api/cache/invalidate")
async def invalidate_cache():
    await FmCacheManager.clear()
    return {"ok": True}

Retry

from fastapi_memory import default_retry

@default_retry()
async def call_upstream():
    resp = await client.get(url)
    resp.raise_for_status()
    return resp.json()

Cached singleton

from fastapi_memory import cached_singleton

class Settings:
    BASE_URL: str = "http://api.example.com:8080"

@cached_singleton
def get_settings() -> Settings:
    return Settings()

Resilient HTTP client

from fastapi_memory import FmResilientClient

upstream = FmResilientClient(base_url="http://api.example.com:8080")