Check browser compatibility for a specific web platform feature using MDN Browser Compat Data (BCD).

Returns version support across browsers, Baseline status, and links to MDN/spec documentation.

Args:

• feature (string): BCD identifier in dot notation (e.g., "api.PushManager", "css.properties.grid", "javascript.builtins.Promise")

• browsers (string[], optional): Filter to specific browsers (e.g., ["chrome", "safari"]). Defaults to desktop browsers.

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: Browser support versions, Baseline status, standard/experimental/deprecated flags, and MDN/spec links.

Examples:

• "Is Push API supported in Safari?" → feature: "api.PushManager"

• "Can I use CSS grid?" → feature: "css.properties.grid"

• "Is Array.at() widely available?" → feature: "javascript.builtins.Array.at"

Compare browser compatibility across multiple web platform features side by side.

Useful for choosing between alternative APIs or understanding support differences.

Args:

• features (string[]): 2-5 BCD feature identifiers to compare (e.g., ["api.fetch", "api.XMLHttpRequest"])

• browsers (string[], optional): Filter to specific browsers. Omit for default desktop browsers.

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: Side-by-side comparison table showing version support for each feature across browsers.

Examples:

• Compare fetch vs XMLHttpRequest → features: ["api.fetch", "api.XMLHttpRequest"]

• Compare CSS layout methods → features: ["css.properties.grid", "css.properties.flex"]

• Compare storage APIs → features: ["api.localStorage", "api.sessionStorage", "api.IndexedDB"]

Search BCD (Browser Compat Data) features by keyword. Use this to find the correct BCD identifier for compat_check.

Searches across 15,000+ web platform features including APIs, CSS properties, HTML elements, JavaScript built-ins, and more.

Args:

• query (string): Search keyword (e.g., "push", "grid", "service-worker", "fetch")

• category (string, optional): Filter by category ("api", "css", "html", "javascript", "svg", etc.)

• limit (number): Max results (default: 20, max: 100)

• offset (number): Pagination offset (default: 0)

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: List of matching feature IDs with standard/experimental/deprecated status.

Examples:

• "Find Push API features" → query: "push", category: "api"

• "Find CSS grid features" → query: "grid", category: "css"

• "Find all service worker APIs" → query: "serviceworker", category: "api"

Get the Baseline status for a web platform feature from W3C WebDX web-features data.

Baseline indicates whether a feature is supported across all major browsers:

• "high" (Widely Available): Supported for 30+ months across all core browsers

• "low" (Newly Available): Recently became interoperable across all core browsers

• false (Not Baseline): Not yet supported across all core browsers

Args:

• feature (string): web-features identifier in kebab-case (e.g., "container-queries", "push", "view-transitions")

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: Baseline status, browser support versions, related BCD features, and spec links.

Examples:

• "Is container queries Baseline?" → feature: "container-queries"

• "Is the Push API widely available?" → feature: "push"

• "Check View Transitions baseline" → feature: "view-transitions"

List web platform features filtered by their Baseline status.

Use this to discover which features are Widely Available, Newly Available, or not yet Baseline.

Args:

• status (string, optional): Filter by "high" (Widely Available), "low" (Newly Available), or "false" (Not Baseline)

• group (string, optional): Filter by feature group (e.g., "css", "javascript", "forms")

• limit (number): Max results (default: 20, max: 100)

• offset (number): Pagination offset (default: 0)

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: Paginated list of features with their Baseline status and availability dates.

Examples:

• "List all Widely Available features" → status: "high"

• "What CSS features are Newly Available?" → status: "low", group: "css"

• "What features aren't Baseline yet?" → status: "false"

List all browsers tracked in MDN Browser Compat Data with their current versions and release dates.

Args:

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: List of browsers with id, name, type (desktop/mobile/server), current version, and release date.

Examples:

• "What browsers are tracked?" → no params needed

• "List all browser versions" → no params needed

Find web platform features that were added in a specific browser version.

Useful for understanding what new capabilities became available in a particular browser release.

Args:

• browser (string): Browser identifier (e.g., "safari", "chrome", "firefox")

• version (string): Browser version (e.g., "17.0", "120", "121")

• category (string, optional): Filter by BCD category (e.g., "api", "css")

• limit (number): Max results (default: 20, max: 100)

• offset (number): Pagination offset (default: 0)

• response_format ('markdown' | 'json'): Output format (default: 'markdown')

Returns: List of features added in the specified browser version.

Examples:

• "What was added in Safari 17.0?" → browser: "safari", version: "17.0"

• "New CSS features in Chrome 120" → browser: "chrome", version: "120", category: "css"

• "Firefox 121 API additions" → browser: "firefox", version: "121", category: "api"