# fastapi/asyncer

Asyncer, async and await, focused on developer experience.

Repository: https://github.com/fastapi/asyncer
Canonical: https://ross.abutalabs.com/products/asyncer
Homepage: https://asyncer.tiangolo.com/
Language: Python
License: MIT
License Family: permissive
Topics: python, async, asyncio, trio, anyio
Last push: 2026-08-25T16:40:06+00:00

## Health v2 (maintenance only)
Score: 96/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 90, longevity 100
- inputs: {"age_days": 1702, "days_push": 8, "days_rel": 69, "gap_med": 19, "n_releases_24m": 10}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2485, forks 89 (observed 2026-08-28T04:06:55.526210+00:00)

## What it is
Asyncer is a small Python library built on AnyIO that provides a handful of utility functions for working with async/await and concurrent code with a focus on developer experience. It improves editor autocompletion, inline errors, and mypy type-checking support, and simplifies mixing async code with blocking code.

## Use cases
- run async tasks concurrently in python with better type checking
- mix blocking and async code in python
- get autocompletion and inline errors for asyncio code
- run functions in a worker thread from async code
- simplify asyncio and trio compatibility in my project

## When to choose
- you want a tiny, opinionated wrapper over AnyIO with excellent editor and mypy support
- you need to combine sync blocking calls with async code conveniently
- you already like the FastAPI ecosystem's developer-experience philosophy

## When to avoid
- you need a full-featured async framework or advanced concurrency primitives
- you can't pin versions, since the API may still change
- you want to avoid extra dependencies for just four functions

## Facets
- artifact type: library
- maturity: active
- function: concurrency, developer-tools
- domain: developer-tools, programming-languages
- platform: python, cross-platform
- tags: asyncio, anyio, trio, async-await, developer-experience, type-checking

## Member repositories
- fastapi/asyncer (main) score 96

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:55.526210+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:28:03.985906+00:00, confidence not recorded.
  - readme: https://github.com/fastapi/asyncer (fetched 2026-08-28T04:06:55.526210+00:00, sha bd63cddbdd30)
  - homepage: https://asyncer.tiangolo.com/ (fetched 2026-08-29T10:10:12.129415+00:00, sha 08ee9c4790f2)
  - site_page: https://asyncer.tiangolo.com/about (fetched 2026-08-29T10:10:12.132150+00:00, sha 3f8eb1daba56)
  - site_page: https://asyncer.tiangolo.com/tutorial/install (fetched 2026-08-29T10:10:12.133802+00:00, sha 1d5b269a09d7)
  - registry_pypi: https://pypi.org/pypi/asyncer/json (fetched 2026-08-29T10:10:12.135375+00:00, sha df54d78c2081)
- Data as of 2026-08-30T08:39:29.467469+00:00.