a11y-toolkit: The Accessibility Layer for AI Coding Agents

19 MCP tools + 5 prompts + a skill covering the full WCAG 2.2 loop: audit (static + rendered, including shadow DOM, 320px reflow, keyboard traps, infinite scroll, form errors, W3C Nu validation), FIX (deterministic safe autofix + contrast math including text-over-image pixel sampling), DOCUMENT (EAA/RD 1112/2018 accessibility statements), WATCH (error budget, SARIF export, regression diffs) and HAND OFF (countersignature-ready evidence pack with SHA-256 hash chain).

43 of 54 WCAG 2.2 A/AA criteria carry automated signals. The remaining 11 are documented with their manual verification protocol — the toolkit prints the machine/human boundary on every report. Benchmarked monthly against axe-core on real pages including gov.uk.

Zero dependencies at the core (Python stdlib). Bilingual es/en. MIT license. Available on PyPI, the official MCP Registry and GitHub.