# oasdiff/oasdiff

OpenAPI Diff and Breaking Changes

Repository: https://github.com/oasdiff/oasdiff
Canonical: https://ross.abutalabs.com/products/oasdiff
Homepage: https://www.oasdiff.com
Language: Go
License: Apache-2.0
License Family: permissive
Topics: swagger, openapi3, openapi-specification, diff, golang, openapi-spec, breaking-changes, openapi, go, rest-api, changelog, github-actions, openapi30, openapi31, side-by-side, openapi-validation, openapi-validator
Last push: 2026-08-25T06:59:17+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 86, longevity 100
- inputs: {"age_days": 2030, "days_push": 8, "days_rel": 17, "gap_med": 2.0, "n_releases_24m": 63}
- flags: no_readme
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1330, forks 104 (observed 2026-08-28T04:04:24.011799+00:00)

## What it is
oasdiff is a Go CLI tool and GitHub Action that diffs OpenAPI/Swagger specifications and detects breaking API changes, generating changelogs, side-by-side reviews, and validation reports. It integrates into CI pipelines to block merges containing unapproved breaking changes and supports OpenAPI 3.0/3.1 migration-aware comparisons.

## Use cases
- detect breaking changes between two openapi specs in ci
- fail a pull request when the api contract breaks
- generate a changelog from openapi spec diffs
- migrate openapi 3.0 specs to 3.1 without false-positive diffs
- compare microservice api specs behind a gateway
- validate an openapi spec against openapi and  schema rules
- share a side-by-side api spec review with teammates

## When to choose
- you maintain a REST API with an OpenAPI spec and want to prevent accidental breaking changes
- you need automated API contract checks in GitHub Actions or other CI
- you want changelogs or diffs generated from OpenAPI definitions
- you're migrating specs between OpenAPI 3.0 and 3.1+

## When to avoid
- you need runtime API testing or mocking rather than spec diffing
- your API has no machine-readable OpenAPI/Swagger definition
- you need GraphQL or gRPC contract diffing

## Facets
- artifact type: cli-tool
- maturity: active
- function: developer-tools, api-framework, ci-cd, documentation
- domain: apis, developer-tools, web-development
- platform: cli, windows, go
- tags: openapi, swagger, breaking-changes, api-diff, changelog, github-actions, rest-api, spec-validation, automation, linux, macos, docker

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

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:24.011799+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 2026-08-30T04:45:32.549578+00:00, confidence not recorded.
  - homepage: https://www.oasdiff.com (fetched 2026-08-29T12:04:41.680058+00:00, sha 306e37347109)
  - site_page: https://www.oasdiff.com/docs/openapi-31-migration (fetched 2026-08-29T12:04:41.697623+00:00, sha caddb58e4860)
  - site_page: https://www.oasdiff.com/docs/breaking-changes (fetched 2026-08-29T12:04:41.691537+00:00, sha d728aeb88ce1)
  - site_page: https://www.oasdiff.com/docs/getting-started (fetched 2026-08-29T12:04:41.694119+00:00, sha 14913d5285b2)
  - site_page: https://www.oasdiff.com/docs/github-action (fetched 2026-08-29T12:04:41.695843+00:00, sha df79251a4de2)
  - site_page: https://www.oasdiff.com/docs/microservices (fetched 2026-08-29T12:04:41.699298+00:00, sha 744824640f9e)
  - site_page: https://www.oasdiff.com/docs (fetched 2026-08-29T12:04:41.700824+00:00, sha 6ccfd8a6ce11)
  - site_page: https://www.oasdiff.com/pricing (fetched 2026-08-29T12:04:41.689610+00:00, sha b3551add10c4)
- Data as of 2026-08-30T08:39:29.467469+00:00.