oasdiff is a command-line application for comparing OpenAPI specifications and identifying changes that could break existing API clients. It can also validate individual specifications for structural problems, making it useful throughout the API development process.
The application understands the structure of OpenAPI documents rather than simply comparing lines of YAML or JSON. It can identify changes to endpoints, parameters, schemas, authentication requirements and other parts of an API contract.
A central feature is its breaking-change detection. oasdiff distinguishes between modifications that will break existing clients, changes that may cause compatibility problems and changes that are unlikely to affect consumers. Developers can use these findings to prevent accidental API regressions.
oasdiff also provides a standalone validation command that checks specifications for invalid types, missing required fields, unresolved references and other violations. The application runs locally and can be integrated into continuous integration workflows, including GitHub Actions.
This is free and open source software.
Key Features
- Compare OpenAPI specifications and identify structural differences.
- Detect breaking changes that could affect existing API consumers.
- Validate individual specifications against OpenAPI and JSON Schema requirements.
- Check for missing required fields, invalid types, malformed expressions and unresolved references.
- Classify changes by severity, including errors, warnings and informational findings.
- Customise severity levels and exclude particular categories of changes.
- Generate detailed changelogs and compatibility reports.
- Produce output in formats including JSON, YAML, HTML, Markdown and plain text.
- Compare specifications stored locally, at remote URLs or in Git revisions.
- Analyse APIs spread across multiple specification files.
- Handle changes involving schema composition, parameters, nullability and security requirements.
- GitHub Actions integration for checking API changes during pull requests.
- Pre-commit integration for checking changes before they enter a repository.
- Cross-platform support – runs on Linux, macOS and Windows.
Website: github.com/oasdiff/oasdiff
Support:
Developer: oasdiff contributors
License: Apache License 2.0
oasdiff is written in Go. Learn Go with our recommended free books and free tutorials.
Related Software
| OpenAPI Linters | |
|---|---|
| Spectral | Fexible JSON/YAML linter |
| vacuum | OpenAPI and Swagger linter |
| Redocly | All-in-one OpenAPI utility |
| Cherrybomb | Audit, validate, run API tests |
| Zally | Minimalistic, simple-to-use API linter |
| speccy | Enforce quality rules on your OpenAPI specifications |
| Rate My OpenAPI | Improve the quality of your OpenAPI specifications |
| OpenAPI Validator | Configurable and extensible validator/linter |
| OpenAPI Spec validator | Validates OpenAPI Specs |
| oval | CLI for (O)penAPI Specification document (val)idation |
| OpenAPI Linter | CLI and a Node.js library |
| OAS-Kit | Convert Swagger 2.0 definitions to OpenAPI 3.0 |
Read our verdict in the software roundup.
 Explore our carefully curated directory of recommended free and open source software, covering every major software category.The directory forms part of our extensive collection of articles for Linux enthusiasts. It includes hundreds of detailed reviews, together with free and open source alternatives to proprietary software from companies such as Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. LinuxLinks also covers interesting projects worth exploring, Linux-compatible hardware, free programming books and tutorials, and much more. Know a useful free and open source Linux application that we haven’t covered? Tell us about it using our submission form. |
Please read our Comment Policy before commenting.