aiohttp

library3.14.3pypypi✓ verified 29d ago

Async HTTP client/server framework for asyncio. Provides both a client (ClientSession) and a web server (web.Application). Current version is 3.13.3 (Jan 2026). Has removed several long-deprecated parameters that LLMs still generate.

http-networking web-framework

pip install aiohttp

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · AIOHTTP

aiohttp

http-networkingpythonv3.14.3

Install

4.8s avg

Import

587ms

Disk

35MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v3.14.3 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.623s · 34.6MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 4.8s · import 0.551s · 38MB

35MB installed

● package 35MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

ClientSession

✓ from aiohttp import ClientSession

✗ import aiohttp

web

✓ from aiohttp import web

✗ import aiohttp

ClientTimeout

✓ from aiohttp import ClientTimeout

✗ import aiohttp

Client with ClientTimeout and basic web server setup.

import aiohttp import asyncio async def main(): timeout = aiohttp.ClientTimeout(total=30) async with aiohttp.ClientSession(timeout=timeout) as session: async with session.get('https://httpbin.org/get') as resp: print(resp.status) data = await resp.json() print(data) asyncio.run(main()) # Server from aiohttp import web async def handle(request): return web.Response(text='Hello') app = web.Application() app.add_routes([web.get('/', handle)]) web.run_app(app)

Debug

Known issues

breakingtimeout= parameter must be aiohttp.ClientTimeout, not int/float. Passing timeout=30 raises AttributeError: 'int' object has no attribute 'total' at request time, not at session creation. The error is confusing and delayed.

fix

timeout = aiohttp.ClientTimeout(total=30, connect=10)
async with aiohttp.ClientSession(timeout=timeout) as session: ...

affects: >= 3.9

breakingloop= parameter removed from ClientSession, TCPConnector, and all other aiohttp objects. Was deprecated for years; removed in 3.9. LLM-generated code from older tutorials passes loop=asyncio.get_event_loop().

fix

Remove all loop= arguments. aiohttp uses the running event loop automatically.

affects: >= 3.9

breakingread_timeout and conn_timeout constructor parameters removed from ClientSession. Replaced by ClientTimeout.

fix

Use aiohttp.ClientTimeout(total=..., connect=..., sock_read=...) instead.

affects: >= 3.9

breakingverify_ssl=, ssl_context=, and fingerprint= parameters deprecated in request methods. Replaced by unified ssl= parameter.

fix

Use ssl=False to skip verification, ssl=ssl_context for custom context, ssl=aiohttp.Fingerprint(...) for fingerprint pinning.

affects: >= 3.9

deprecatedapp.loop, request.loop, client.loop, connector.loop properties deprecated and scheduled for removal in aiohttp 4.0.

fix

Use asyncio.get_event_loop() or asyncio.get_running_loop() directly.

affects: >= 3.9

gotchaCreating ClientSession outside of an async context (e.g. at module level or in __init__) raises DeprecationWarning and will raise RuntimeError in a future version.

fix

Always create ClientSession inside an async function or use async with at the point of use.

affects: all

gotchaResponse body must be consumed before the response context manager exits, or the connection is left in a broken state. await resp.json() / await resp.text() / await resp.read() must be called inside the async with block.

fix

Always consume the response body inside the async with session.get(...) as resp: block.

affects: all

Upgrade

Version history

3.14.3latest on PyPI · released Jul 23, 2026

Audit

Dependencies

aiodnsoptionalFaster DNS resolution. Included in aiohttp[speedups]. Highly recommended.

brotlioptionalBrotli decompression support. Included in aiohttp[speedups].

Agent activity

94 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/aio-libs/aiohttp ↗

packagehttps://pypi.org/project/aiohttp/ ↗

homepagehttps://docs.aiohttp.org ↗