# schemathesis/schemathesis

Catch API bugs before your users do

Repository: https://github.com/schemathesis/schemathesis
Canonical: https://ross.abutalabs.com/products/schemathesis
Homepage: https://schemathesis.readthedocs.io
Language: Python
License: MIT
License Family: permissive
Topics: hypothesis, pytest, swagger, cli, property-based-testing, graphql, openapi, testing, api, api-testing, fuzzing
Last push: 2026-08-26T20:12:36+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 2571, "days_push": 7, "days_rel": 9, "gap_med": 2.0, "n_releases_24m": 183}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3564, forks 223 (observed 2026-08-28T04:08:09.891809+00:00)

## What it is
Schemathesis is a Python-based API testing tool that automatically generates test cases from OpenAPI and GraphQL schemas using property-based testing. It runs as a CLI or integrates with pytest to find server errors, schema violations, and stateful bugs before users do.

## Use cases
- fuzz my REST API for 500 errors
- test that API responses match the OpenAPI schema
- find edge case inputs that crash my API
- run automated API tests in CI from an OpenAPI spec
- stateful API workflow testing like create then delete
- test a GraphQL API automatically
- detect validation bypasses in my API

## When to choose
- you have an OpenAPI or GraphQL schema and want automated bug discovery without writing test cases
- you want property-based API testing integrated with pytest or CI/CD

## When to avoid
- you need to test APIs without any schema definition
- you need manual, scripted end-to-end UI tests

## Facets
- artifact type: cli-tool
- maturity: active
- function: testing, fuzzing, e2e-testing, cli, http-client
- domain: testing, apis, developer-tools
- platform: python, cli, cross-platform
- tags: openapi, graphql, property-based-testing, api-testing, hypothesis, pytest, swagger, stateful-testing, automation

## Member repositories
- schemathesis/schemathesis (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:09.891809+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 2026-08-29T18:34:11.446740+00:00, confidence not recorded.
  - readme: https://github.com/schemathesis/schemathesis (fetched 2026-08-28T04:08:09.891809+00:00, sha a6a3122624c0)
- Data as of 2026-08-30T08:39:29.467469+00:00.