Filter by tag
Enable or disable any rule — disabled rules are skipped whenever you lint that artifact type (stored in this browser). Grouped by artifact.
Apply a transformation to the current document, grouped by artifact type. Some create new entries in Saved Artifacts; the primary document is always kept. More functions coming.
Your documents autosave to this browser's local storage as you edit — no account needed. They'll disappear if you clear your browser cache. Commit or open a PR to save one to a repo from the Repos tab (needs a GitHub token).
Rules you save here override the built-in rule of the same name when linting, and persist in this browser. Remove one to revert to the original. Edit a rule from any result to save it.
Add the GitHub repos you work with — stored in this browser and offered wherever you commit or open a PR (saving artifacts & rulesets to Git is coming soon). Needs a GitHub token (Config).
Stored only in this browser's local storage (cleared by Reset or clearing your cache). These power code search across Git hosts and saving artifacts & rules to Git. Nothing is sent anywhere until you use those features.
Search sources
Where Search looks for artifacts. GitHub is on by default; GitLab & Bitbucket need their tokens below.
Git tokens
API Validator
A browser-first API governance tool. Lint OpenAPI, AsyncAPI, Arazzo, and JSON Schema against a best-of-breed ruleset powered by Spectral — entirely in your browser. No backend and no accounts; your tokens and documents never leave this page.
What you can do
- Search & load real artifacts from GitHub / GitLab / Bitbucket with your own token, or upload a file from disk.
- Edit in a Monaco editor with a YAML ⇄ JSON toggle.
- Lint against curated rules; every finding links to its rule, which you can retune (severity, message, description) or disable — overrides persist in your browser.
- Document — generate readable docs for the current artifact and download them as HTML or Markdown.
- Transform — bundle
$refs, componentize, split by tag/channel/workflow, migrate JSON Schema drafts, and more. - Save & ship — autosave locally, roll everything into an APIs.json 0.21 index, or commit / open a PR to a repo.
- Run offline — download the whole app as a single self-contained file (the “Run Locally” button).
Engine & scope
Powered by the published @stoplight/spectral-* engine, running fully client-side. OpenAPI and AsyncAPI extend Spectral’s built-in spectral:oas / spectral:asyncapi rulesets; Arazzo and JSON Schema are linted by curated inline rules. Scope is deliberately narrow — four artifact types, kept simple.
Rules & credits
The best-of-breed ruleset is compiled from the first-party API Evangelist OpenAPI governance ruleset plus public, redistribution-compatible Spectral rulesets — SPS Commerce, Adidas, Trimble, Paystack, DigitalOcean, Microcks, Baloise, Team Digitale, and Schwarz IT (all Apache-2.0 or MIT). Full attribution and vendored licenses are in THIRD_PARTY_NOTICES.
Part of API Commons
One of the API Commons tools, alongside API Discovery, API Documentation, API Reusability, and MCP Install — all browser-first and free to fork.
A project of API Evangelist, maintained openly under API Commons. Open source and free to fork; API Evangelist offers expert governance services when you want help.