A11ymcp MCP Server

Public pages and HTML fragments provide the starting points for a11ymcp's accessibility workflow. The test_accessibility tool accepts a page URL, while test_html_string accepts markup directly; both let an assistant set viewport dimensions and select accessibility tags. Those tags cover WCAG 2.0, 2.1, and 2.2 checks, alongside best-practice rules. For exploring the checks themselves, get_rules supplies rule identifiers, descriptions, help text, reference links, and tags, with optional tag filtering.

Targeted checks separate specific concerns from broader page testing. check_color_contrast evaluates foreground and background colors with font size and boldness as optional inputs. check_aria_attributes examines markup for ARIA usage, while check_orientation_lock looks for content that imposes a screen orientation. Accessibility results use structured JSON with violation details, affected elements, failure explanations, and counts for passed, incomplete, and inapplicable checks. Built around Axe-core and Puppeteer, the project exposes these capabilities to MCP-compatible clients, including Claude Desktop, Claude Code, VS Code, and Cursor. It requires Node.js 18 or later and is not an official Deque Labs server.