Project identity and accountability
About A2UI Validator
An independent browser tool for checking A2UI v0.9.1 JSON and JSONL before a renderer consumes it.
Independent developer tool
Built around a narrow, verifiable task
A2UI Validator helps developers identify syntax, schema, surface-lifecycle, and component-graph problems before an A2UI payload reaches a renderer. It is an independent project. It is not an official A2UI service and is not affiliated with or endorsed by the A2UI project, Google, or the project maintainers.
Why it exists
Generic JSON validity is only the first layer
Well-formed JSON can still use the wrong A2UI envelope, violate Basic Catalog types, update a surface before creating it, reference a missing component, or contain a cycle. This tool turns those protocol-specific failures into stable codes, precise locations, and repair guidance without requiring an installation or account.
Current release
What is—and is not—supported
The release accepts object, array, and JSONL input for exact A2UI v0.9.1, checks the pinned official Basic Catalog snapshot, and applies deterministic semantic rules in a browser Worker. It does not support v1.0, custom catalogs, URL or file upload, automatic repair, or rendering.
Quality process
Published claims map to runnable evidence
The schema snapshot is pinned to a specific upstream commit and recorded with file hashes. Valid examples and every public broken-to-valid error pair are executed by the production validator core in automated tests. Browser QA then checks the complete local flow, responsive layouts, metadata, navigation, console output, and payload privacy.
Ownership and attribution
Original product work and upstream schemas are separate
The original application interface, product copy, and application code are copyright © 2026 A2UI Validator unless a file states otherwise. The vendored A2UI v0.9.1 schema files come from the A2UI project and retain their Apache-2.0 attribution and license. That upstream license is not presented as a blanket license for all original site work.
View the A2UI Validator source repositoryEditorial corrections
Accuracy matters more than page count
Pages are written for a concrete developer task. We do not publish mass-generated keyword pages, invented benchmarks, ratings, reviews, or unsupported compatibility claims. Material protocol or data-flow changes require the relevant page and tests to be updated together.
Contact and corrections
Report a correctness, privacy, accessibility, or copyright issue
Include the page URL, stable error code or subcode, browser version, and the smallest sanitized reproduction that demonstrates the issue. Do not send access tokens, secrets, or a complete private payload.