Accessibility MCP Server

export interface WCAGMapping { ruleId: string; wcagRefs: string[]; severity: 'critical' | 'serious' | 'moderate' | 'minor'; } const WCAG_MAPPINGS: Record<string, WCAGMapping> = { 'aria-allowed-attr': { ruleId: 'aria-allowed-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-hidden-focus': { ruleId: 'aria-hidden-focus', wcagRefs: ['WCAG2.1:2.1.1', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-required-attr': { ruleId: 'aria-required-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-required-children': { ruleId: 'aria-required-children', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-required-parent': { ruleId: 'aria-required-parent', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-roles': { ruleId: 'aria-roles', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-valid-attr-value': { ruleId: 'aria-valid-attr-value', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-valid-attr': { ruleId: 'aria-valid-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'button-name': { ruleId: 'button-name', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'critical', }, 'color-contrast': { ruleId: 'color-contrast', wcagRefs: ['WCAG2.1:1.4.3', 'WCAG2.1:1.4.6'], severity: 'serious', }, 'document-title': { ruleId: 'document-title', wcagRefs: ['WCAG2.1:2.4.2'], severity: 'moderate', }, 'html-has-lang': { ruleId: 'html-has-lang', wcagRefs: ['WCAG2.1:3.1.1'], severity: 'serious', }, 'image-alt': { ruleId: 'image-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'critical', }, 'input-button-name': { ruleId: 'input-button-name', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'critical', }, 'label': { ruleId: 'label', wcagRefs: ['WCAG2.1:1.3.1', 'WCAG2.1:3.3.2', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'link-name': { ruleId: 'link-name', wcagRefs: ['WCAG2.1:2.4.4', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'list': { ruleId: 'list', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'listitem': { ruleId: 'listitem', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'meta-refresh': { ruleId: 'meta-refresh', wcagRefs: ['WCAG2.1:2.2.1', 'WCAG2.1:2.2.4'], severity: 'serious', }, 'object-alt': { ruleId: 'object-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'serious', }, 'role-img-alt': { ruleId: 'role-img-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'serious', }, 'tabindex': { ruleId: 'tabindex', wcagRefs: ['WCAG2.1:2.1.1'], severity: 'serious', }, 'table-fake-caption': { ruleId: 'table-fake-caption', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'td-headers-attr': { ruleId: 'td-headers-attr', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'th-has-data-cells': { ruleId: 'th-has-data-cells', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'valid-lang': { ruleId: 'valid-lang', wcagRefs: ['WCAG2.1:3.1.2'], severity: 'moderate', }, 'video-caption': { ruleId: 'video-caption', wcagRefs: ['WCAG2.1:1.2.2'], severity: 'serious', }, }; const LIGHTHOUSE_WCAG_MAPPINGS: Record<string, WCAGMapping> = { 'accessibility': { ruleId: 'accessibility', wcagRefs: ['WCAG2.1:1.1.1', 'WCAG2.1:1.3.1', 'WCAG2.1:1.4.3', 'WCAG2.1:2.1.1', 'WCAG2.1:2.4.2', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-allowed-attr': { ruleId: 'aria-allowed-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-hidden-body': { ruleId: 'aria-hidden-body', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-hidden-focus': { ruleId: 'aria-hidden-focus', wcagRefs: ['WCAG2.1:2.1.1', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-input-field-name': { ruleId: 'aria-input-field-name', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-required-attr': { ruleId: 'aria-required-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-roles': { ruleId: 'aria-roles', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-valid-attr-value': { ruleId: 'aria-valid-attr-value', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'aria-valid-attr': { ruleId: 'aria-valid-attr', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'serious', }, 'button-name': { ruleId: 'button-name', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'critical', }, 'color-contrast': { ruleId: 'color-contrast', wcagRefs: ['WCAG2.1:1.4.3', 'WCAG2.1:1.4.6'], severity: 'serious', }, 'document-title': { ruleId: 'document-title', wcagRefs: ['WCAG2.1:2.4.2'], severity: 'moderate', }, 'html-has-lang': { ruleId: 'html-has-lang', wcagRefs: ['WCAG2.1:3.1.1'], severity: 'serious', }, 'html-lang-valid': { ruleId: 'html-lang-valid', wcagRefs: ['WCAG2.1:3.1.1'], severity: 'serious', }, 'image-alt': { ruleId: 'image-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'critical', }, 'input-image-alt': { ruleId: 'input-image-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'critical', }, 'label': { ruleId: 'label', wcagRefs: ['WCAG2.1:1.3.1', 'WCAG2.1:3.3.2', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'link-name': { ruleId: 'link-name', wcagRefs: ['WCAG2.1:2.4.4', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'list': { ruleId: 'list', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'listitem': { ruleId: 'listitem', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'meta-refresh': { ruleId: 'meta-refresh', wcagRefs: ['WCAG2.1:2.2.1', 'WCAG2.1:2.2.4'], severity: 'serious', }, 'object-alt': { ruleId: 'object-alt', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'serious', }, 'tabindex': { ruleId: 'tabindex', wcagRefs: ['WCAG2.1:2.1.1'], severity: 'serious', }, 'td-headers-attr': { ruleId: 'td-headers-attr', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'th-has-data-cells': { ruleId: 'th-has-data-cells', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'moderate', }, 'valid-lang': { ruleId: 'valid-lang', wcagRefs: ['WCAG2.1:3.1.2'], severity: 'moderate', }, 'video-caption': { ruleId: 'video-caption', wcagRefs: ['WCAG2.1:1.2.2'], severity: 'serious', }, 'video-description': { ruleId: 'video-description', wcagRefs: ['WCAG2.1:1.2.3'], severity: 'moderate', }, }; const WAVE_WCAG_MAPPINGS: Record<string, WCAGMapping> = { 'error_alt_missing': { ruleId: 'error_alt_missing', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'critical', }, 'error_alt_link': { ruleId: 'error_alt_link', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'serious', }, 'error_alt_spacer': { ruleId: 'error_alt_spacer', wcagRefs: ['WCAG2.1:1.1.1'], severity: 'moderate', }, 'error_button_empty': { ruleId: 'error_button_empty', wcagRefs: ['WCAG2.1:4.1.2'], severity: 'critical', }, 'error_heading_empty': { ruleId: 'error_heading_empty', wcagRefs: ['WCAG2.1:1.3.1'], severity: 'serious', }, 'error_label_empty': { ruleId: 'error_label_empty', wcagRefs: ['WCAG2.1:1.3.1', 'WCAG2.1:3.3.2'], severity: 'serious', }, 'error_link_empty': { ruleId: 'error_link_empty', wcagRefs: ['WCAG2.1:2.4.4', 'WCAG2.1:4.1.2'], severity: 'serious', }, 'error_missing_form_label': { ruleId: 'error_missing_form_label', wcagRefs: ['WCAG2.1:1.3.1', 'WCAG2.1:3.3.2'], severity: 'serious', }, 'contrast': { ruleId: 'contrast', wcagRefs: ['WCAG2.1:1.4.3', 'WCAG2.1:1.4.6'], severity: 'serious', }, }; export function getWCAGMapping(ruleId: string, tool: 'axe' | 'lighthouse' | 'wave'): WCAGMapping | undefined { switch (tool) { case 'axe': return WCAG_MAPPINGS[ruleId]; case 'lighthouse': return LIGHTHOUSE_WCAG_MAPPINGS[ruleId]; case 'wave': return WAVE_WCAG_MAPPINGS[ruleId]; default: return undefined; } } export function getDefaultWCAGMapping(ruleId: string): WCAGMapping { return { ruleId, wcagRefs: ['WCAG2.1:4.1.2'], severity: 'moderate', }; } export function mapImpactToSeverity(impact: 'critical' | 'serious' | 'moderate' | 'minor' | null): 'critical' | 'serious' | 'moderate' | 'minor' { if (!impact) { return 'moderate'; } return impact; } export function getConfidenceFromImpact(impact: 'critical' | 'serious' | 'moderate' | 'minor' | null): 'high' | 'medium' | 'low' { if (impact === 'critical' || impact === 'serious') { return 'high'; } if (impact === 'moderate') { return 'medium'; } return 'low'; }