Accessibility MCP Server

import type { WaveResult, WaveItem } from '../types/audit.js'; import { resolveUrl, type ResolvedUrl } from '../utils/url-resolver.js'; const DEFAULT_WAVE_API_URL = 'https://wave.webaim.org/api/request'; export interface WaveAdapterOptions { apiKey?: string; apiUrl?: string; } export class WaveAdapter { private readonly apiKey: string | undefined; private readonly apiUrl: string; constructor(options: WaveAdapterOptions = {}) { this.apiKey = options.apiKey ?? process.env.WAVE_API_KEY; this.apiUrl = options.apiUrl ?? process.env.WAVE_API_URL ?? DEFAULT_WAVE_API_URL; } async audit(urlOrPath: string, options?: WaveAdapterOptions): Promise<WaveResult> { const resolved: ResolvedUrl = await resolveUrl(urlOrPath); if (!resolved.url.startsWith('http://') && !resolved.url.startsWith('https://')) { throw new Error('WAVE API only supports HTTP/HTTPS URLs. Local files must be served via a local server.'); } const apiKey = options?.apiKey ?? this.apiKey; const apiUrl = options?.apiUrl ?? this.apiUrl; if (!apiKey) { throw new Error('WAVE API key is required. Set WAVE_API_KEY environment variable or pass apiKey option.'); } let result: WaveResult; try { const requestUrl = new URL(apiUrl); requestUrl.searchParams.set('key', apiKey); requestUrl.searchParams.set('url', resolved.url); requestUrl.searchParams.set('format', 'json'); const response = await fetch(requestUrl.toString(), { method: 'GET', headers: { 'Accept': 'application/json', }, }); if (!response.ok) { throw new Error(`WAVE API request failed: ${response.status} ${response.statusText}`); } const data = await response.json(); result = this.transformResult(data, resolved.url); } finally { if (resolved.cleanup) { await resolved.cleanup(); } } return result; } private transformResult(data: unknown, url: string): WaveResult { if (!data || typeof data !== 'object') { throw new Error('Invalid WAVE API response'); } const waveData = data as { statsummary?: { total?: number; error?: number; contrast?: number; alert?: number; feature?: number; structure?: number; aria?: number; }; categories?: { error?: Array<{ code?: string; count?: number; pages?: number; description?: string; }>; contrast?: Array<{ code?: string; count?: number; pages?: number; description?: string; contrast?: { ratio?: string; large?: boolean; expected?: string; }; }>; alert?: Array<{ code?: string; count?: number; pages?: number; description?: string; }>; feature?: Array<{ code?: string; count?: number; pages?: number; description?: string; }>; structure?: Array<{ code?: string; count?: number; pages?: number; description?: string; }>; aria?: Array<{ code?: string; count?: number; pages?: number; description?: string; }>; }; }; const statsummary = waveData.statsummary ?? {}; const categories = waveData.categories ?? {}; return { statsummary: { total: statsummary.total ?? 0, error: statsummary.error ?? 0, contrast: statsummary.contrast ?? 0, alert: statsummary.alert ?? 0, feature: statsummary.feature ?? 0, structure: statsummary.structure ?? 0, aria: statsummary.aria ?? 0, }, categories: { error: (categories.error ?? []).map((item) => ({ code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', })), contrast: (categories.contrast ?? []).map((item) => { const mappedItem: WaveItem = { code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', }; if (item.contrast) { mappedItem.contrast = { ratio: item.contrast.ratio ?? '', large: item.contrast.large ?? false, expected: item.contrast.expected ?? '', }; } return mappedItem; }), alert: (categories.alert ?? []).map((item) => ({ code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', })), feature: (categories.feature ?? []).map((item) => ({ code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', })), structure: (categories.structure ?? []).map((item) => ({ code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', })), aria: (categories.aria ?? []).map((item) => ({ code: item.code ?? '', count: item.count ?? 0, pages: item.pages ?? 0, description: item.description ?? '', })), }, url, timestamp: new Date().toISOString(), }; } }