API Validator
API Validator is a free, open-source browser application for checking API descriptions against a Spectral-powered governance ruleset.
What API Validator is
API Validator is a free, open-source browser application for checking API descriptions against a Spectral-powered governance ruleset. It handles OpenAPI 3.x, Swagger 2.0, AsyncAPI, Arazzo, and JSON Schema, with built-in Spectral rulesets for OpenAPI and AsyncAPI and curated inline rules for Arazzo and JSON Schema. You can upload a file or search GitHub, GitLab, and Bitbucket with your own access tokens. The Monaco editor supports YAML and JSON, and findings can be filtered, retuned, or disabled; saved overrides remain in browser storage. API Validator can create HTML or Markdown documentation, bundle references, componentize documents, split them by tag, channel, or workflow, and migrate JSON Schema drafts. Documents autosave locally and can be assembled into an APIs.json 0.21 index, committed, or submitted as a pull request. The maker says there are no accounts or backend, and documents and tokens stay in the browser. The entire application can also be downloaded as one self-contained file for offline use.
Good
- Free plan and open-source Apache-2.0 code
- Supports OpenAPI, AsyncAPI, Arazzo, and JSON Schema
- Rule overrides persist in browser storage
- Generates HTML or Markdown documentation
- Can run offline as one downloaded file
Watch out
- Scope is deliberately limited to four artifact types
- No CI/CD integration
- Repository requests require users’ own tokens
Who it suits
It suits developers and API teams wanting a deliberately narrow validator for four main artifact families. It is also useful for teams that need browser-based editing, repository connections, or offline local use.
Verdict
API Validator combines linting, editing, transformations, documentation, and repository actions in a browser. Its narrow scope and lack of CI/CD integration are important constraints for broader governance workflows.
The facts
Each one read from API Validator's own pages, with the date it was checked.
What it does
- Artifact search
- Users can search GitHub, GitLab, and Bitbucket for artifacts using their own tokens, or upload a file from disk.checked 7 Oct 2001
- Documentation
- The tool can generate documentation for the current artifact and download it as HTML or Markdown.checked 7 Oct 2001
- Editing
- The editor uses Monaco and supports switching between YAML and JSON.checked 7 Oct 2001
- Git integrations
- It can search GitHub, GitLab, and Bitbucket using the user's own token and can commit changes or open a pull request to a repository.checked 7 Oct 2001
- Intended audience
- The maker describes it as a simple, deliberately narrow validator for four API artifact types.checked 7 Oct 2001
- License
- The repository states that the code is licensed under Apache-2.0.checked 7 Oct 2001
- Limits
- The maker describes its scope as deliberately limited to four artifact types.checked 7 Oct 2001
- Lint engine
- It uses the Spectral engine, with built-in Spectral rulesets for OpenAPI and AsyncAPI and curated inline rules for Arazzo and JSON Schema.checked 7 Oct 2001
- Local storage
- Documents, tokens, saved artifacts, and rule overrides are stored in browser local storage; Git-host requests are sent directly from the browser when those features are used.checked 7 Oct 2001
- Local use
- The Run Locally button downloads the whole app as a self-contained file that can run offline.checked 7 Oct 2001
- Maintainer
- The project is maintained openly under API Commons and is a project of API Evangelist.checked 7 Oct 2001
- Offline use
- The entire app can be downloaded as a single self-contained file for local use.checked 7 Oct 2001
- Pricing and licensing
- The project is open source and free to fork; API Evangelist offers expert governance services for users who want help.checked 7 Oct 2001
- Privacy
- The maker says the app has no backend or accounts and that tokens and documents stay in the browser.checked 7 Oct 2001
- Purpose
- API Validator lints API descriptions against a Spectral-powered governance ruleset in the browser.checked 7 Oct 2001
- Rule controls
- Users can filter, disable, or retune rules; saved overrides persist in the browser.checked 7 Oct 2001
- Rules
- Users can adjust a finding’s severity, message, or description, or disable its rule; saved overrides persist in the browser.checked 7 Oct 2001
- Save and publish
- Documents autosave to browser local storage, can be assembled into an APIs.json 0.21 index, and can be committed or submitted as a pull request to a repository.checked 7 Oct 2001
- Support
- The project says API Evangelist offers expert governance services for teams seeking help.checked 7 Oct 2001
- Supported formats
- It supports OpenAPI, AsyncAPI, Arazzo, and JSON Schema.checked 7 Oct 2001
- Transformations
- Utilities include bundling $refs, componentizing, splitting by tag, channel, or workflow, and migrating JSON Schema drafts.checked 7 Oct 2001
The company
- Headquarters
- San Francisco, CAchecked 28 Sep 2001
- Maker
- API Validator is a project of API Evangelist and is maintained under API Commons.checked 7 Oct 2001
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