Accessibility MCP Server

import type { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { ListToolsRequestSchema, CallToolRequestSchema } from '@modelcontextprotocol/sdk/types.js'; import { AuditExecutor } from '../services/audits/audit-executor.js'; const executor = new AuditExecutor(); const TOOLS = [ { name: 'axe_audit', description: 'Run an accessibility audit using axe-core via Playwright. Supports URLs, local file paths, and localhost URLs.', inputSchema: { type: 'object', properties: { url: { type: 'string', description: 'The URL to audit (http://, https://), local file path (./file.html), or file:// URL', }, options: { type: 'object', description: 'Optional axe-core configuration', properties: { tags: { type: 'array', items: { type: 'string' }, description: 'WCAG tags to include (e.g., ["wcag2a", "wcag2aa"])', }, rules: { type: 'object', description: 'Rule-specific configuration', }, timeout: { type: 'number', description: 'Timeout in milliseconds', }, browser: { type: 'string', enum: ['chromium', 'firefox', 'webkit'], description: 'Browser to use', }, }, }, }, required: ['url'], }, }, { name: 'lighthouse_audit', description: 'Run an accessibility audit using Lighthouse CLI. Supports URLs, local file paths, and localhost URLs.', inputSchema: { type: 'object', properties: { url: { type: 'string', description: 'The URL to audit (http://, https://), local file path (./file.html), or file:// URL', }, categories: { type: 'array', items: { type: 'string' }, description: 'Lighthouse categories to include (default: accessibility)', }, options: { type: 'object', description: 'Optional Lighthouse configuration', properties: { onlyCategories: { type: 'array', items: { type: 'string' }, description: 'Categories to include', }, skipAudits: { type: 'array', items: { type: 'string' }, description: 'Audits to skip', }, timeout: { type: 'number', description: 'Timeout in milliseconds', }, }, }, }, required: ['url'], }, }, { name: 'wave_audit', description: 'Run an accessibility audit using WAVE API (requires WAVE_API_KEY). Supports URLs and localhost URLs. Local files are automatically served via temporary local server.', inputSchema: { type: 'object', properties: { url: { type: 'string', description: 'The URL to audit (http://, https://), local file path (./file.html), or localhost URL. Local files will be served via temporary server.', }, apiKey: { type: 'string', description: 'WAVE API key (optional, uses WAVE_API_KEY env var if not provided)', }, }, required: ['url'], }, }, ]; export async function registerTools(server: Server): Promise<void> { server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: TOOLS, }; }); server.setRequestHandler(CallToolRequestSchema, async (request) => { const toolName = request.params.name as string; const args = request.params.arguments as Record<string, unknown>; switch (toolName) { case 'axe_audit': { if (!args?.url || typeof args.url !== 'string') { throw new Error('URL is required'); } const result = await executor.executeAxeAudit(args.url, args.options as Record<string, unknown>); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; } case 'lighthouse_audit': { if (!args?.url || typeof args.url !== 'string') { throw new Error('URL is required'); } const config: { categories?: string[]; timeout?: number; onlyCategories?: string[]; skipAudits?: string[]; } = {}; if (args.categories !== undefined) { config.categories = args.categories as string[]; } if (args.options && typeof args.options === 'object') { const opts = args.options as Record<string, unknown>; if (opts.timeout !== undefined) { config.timeout = opts.timeout as number; } if (opts.onlyCategories !== undefined) { config.onlyCategories = opts.onlyCategories as string[]; } if (opts.skipAudits !== undefined) { config.skipAudits = opts.skipAudits as string[]; } } const result = await executor.executeLighthouseAudit(args.url, config); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; } case 'wave_audit': { if (!args?.url || typeof args.url !== 'string') { throw new Error('URL is required'); } const config: { apiKey?: string } = {}; if (args.apiKey !== undefined) { config.apiKey = args.apiKey as string; } const result = await executor.executeWaveAudit(args.url, config); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; } default: throw new Error(`Unknown tool: ${toolName}`); } }); }