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Building a Production-Ready Async API Client in Python

Building a Production-Ready Async API Client in Python

When you need to fetch data from multiple APIs concurrently,
a synchronous approach will kill performance. Here's how I built
an async client that handles 10k requests/min without breaking a sweat.

The Problem

  • Single-threaded HTTP requests are slow
  • Threading is complex in Python
  • You need error handling, timeouts, retries

The Solution: Async/Await

import httpx
import asyncio

class AsyncAPIClient:
    def __init__(self, base_url, api_key=None):
        self.base_url = base_url
        self.api_key = api_key
        self.client = None

    async def __aenter__(self):
        headers = {"Authorization": f"Bearer {self.api_key}"} if self.api_key else {}
        self.client = httpx.AsyncClient(base_url=self.base_url, headers=headers)
        return self

    async def __aexit__(self, *args):
        await self.client.aclose()

    async def get(self, endpoint):
        response = await self.client.get(endpoint)
        response.raise_for_status()
        return response.json()

    async def batch_get(self, endpoints):
        tasks = [self.get(ep) for ep in endpoints]
        return await asyncio.gather(*tasks)
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Usage

async def main():
    async with AsyncAPIClient("https://api.example.com", "token") as client:
        results = await client.batch_get(["/users", "/posts", "/comments"])
        print(results)

asyncio.run(main())
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Why This Works

  1. Non-blocking I/O — CPU waits for network, other requests run meanwhile
  2. Native Python — No threads, no GIL issues
  3. Type-safe — Works with Pydantic for validation

Benchmarks

  • Sync client: 10s para 100 requests
  • Async client: 0.5s para 100 requests
  • That's 20x faster.

Available on GitHub: [link a tu repo]


Hit "Publish" y comparte en LinkedIn.

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