--- name: servo-fetch description: "Fetch and render web pages using the Servo browser engine — a single binary with JS execution, CSS layout, screenshots, and content extraction. Use when a URL returns empty or incomplete content with plain HTTP fetch, when you need a screenshot without GPU, or when you need to run JavaScript in a page context. No browser download required." --- # servo-fetch ## When to use - A URL returns empty or incomplete content with simple HTTP fetch (SPA, React, Vue) - You need a screenshot of a web page in CI/Docker (no GPU available) - You need to evaluate JavaScript in a page context (DOM queries, data extraction) - You want clean Markdown from a documentation site, blog, or article - You need to crawl an entire documentation site or blog for RAG / knowledge ingestion - You need the accessibility tree with bounding boxes for a page ## When NOT to use - The page is simple static HTML (use `curl` or built-in web fetch instead) - You need to interact with the page (click, fill forms) — servo-fetch is read-only - You need full Chromium compatibility for complex web apps ## Tools (MCP) Start the MCP server: `servo-fetch mcp` (stdio) or `servo-fetch mcp --port 8080` (Streamable HTTP) ### fetch Extract readable content from a URL. JavaScript is executed, CSS layout is computed, and navigation noise (navbars, sidebars, footers, cookie banners) is stripped automatically. Parameters: - `url` (required): URL to fetch (http/https only) - `format`: `"markdown"` (default), `"json"`, `"html"`, `"text"`, or `"accessibility_tree"` - `selector`: CSS selector to extract a specific section instead of full-page extraction - `max_length`: max characters to return (default 5000) - `start_index`: character offset for pagination - `timeout`: page load timeout in seconds (default 30) - `settle_ms`: extra wait in ms after load event for SPAs (default 0, max 10000) ```text fetch(url: "https://docs.rs/tokio", format: "markdown") fetch(url: "https://example.com", format: "json", selector: "article") fetch(url: "https://example.com", format: "accessibility_tree") ``` PDF URLs are auto-detected via Content-Type and extracted directly. ### batch_fetch Fetch multiple URLs in parallel. Results are returned as separate content entries in completion order. Failed URLs are reported inline without aborting the batch. Parameters: - `urls` (required): array of URLs to fetch (http/https only, max 20) - `format`: `"markdown"` (default) or `"json"` - `selector`: CSS selector to extract a specific section - `max_length`: max characters per URL result (default 5000) - `timeout`: page load timeout in seconds per URL (default 30) - `settle_ms`: extra wait in ms after load event (default 0, max 10000) ```text batch_fetch(urls: ["https://a.com", "https://b.com"], format: "markdown") batch_fetch(urls: ["https://a.com", "https://b.com"], format: "json", selector: "article") ``` ### crawl Crawl a website starting from a URL, following same-site links via BFS. JavaScript is executed, CSS layout is computed, and navigation noise is stripped. Respects robots.txt. Parameters: - `url` (required): starting URL to crawl (http/https only) - `limit`: max pages to crawl (default 20, max 500) - `max_depth`: max link depth from seed (default 3, max 10) - `format`: `"markdown"` (default) or `"json"` - `include_glob`: URL path patterns to include (e.g. `["/docs/**"]`) - `exclude_glob`: URL path patterns to exclude - `max_length`: max characters per page result (default 5000) - `timeout`: page load timeout in seconds per page (default 30) - `settle_ms`: extra wait in ms after load event (default 0, max 10000) - `selector`: CSS selector to extract a specific section per page ```text crawl(url: "https://docs.example.com", limit: 20, max_depth: 3) crawl(url: "https://docs.example.com", include_glob: ["/guide/**"], limit: 50) ``` ### screenshot Capture a PNG screenshot. Uses Servo's software renderer — works without GPU. Parameters: - `url` (required): URL to capture - `full_page`: capture the full scrollable page (default false) - `timeout`: page load timeout in seconds (default 30) - `settle_ms`: extra wait in ms after load event (default 0, max 10000) ```text screenshot(url: "https://example.com") screenshot(url: "https://example.com", full_page: true) ``` ### execute_js Evaluate a JavaScript expression after the page loads. Console messages (log, warn, error) are appended to the result. Parameters: - `url` (required): URL to load - `expression` (required): JavaScript expression to evaluate - `timeout`: page load timeout in seconds (default 30) - `settle_ms`: extra wait in ms after load event (default 0, max 10000) ```text execute_js(url: "https://example.com", expression: "document.title") execute_js(url: "https://example.com", expression: "[...document.querySelectorAll('h2')].map(e => e.textContent)") ``` ## CLI ```bash servo-fetch https://example.com # Markdown (default) servo-fetch https://example.com --json # Structured JSON servo-fetch URL1 URL2 URL3 # Parallel batch (Markdown with separators) servo-fetch URL1 URL2 --json # Parallel batch (NDJSON) servo-fetch https://example.com --screenshot out.png servo-fetch https://example.com --js "document.title" servo-fetch https://example.com --selector article servo-fetch https://example.com --raw html # Raw HTML servo-fetch https://example.com --raw text # Plain text servo-fetch https://example.com -t 60 # Custom timeout servo-fetch https://example.com --settle 500 # Extra wait for SPAs servo-fetch crawl https://docs.example.com --limit 20 # Crawl a site (BFS) servo-fetch crawl https://docs.example.com --include "/docs/**" # Crawl with path filter ``` ## Gotchas - Servo's web compatibility is improving but not at Chromium level — best for docs, blogs, and SSR sites - Private/reserved IP addresses are blocked (SSRF protection) - Default timeout is 30 seconds; increase with `timeout` parameter for slow pages - Cookie banners and newsletter popups are stripped via injected user stylesheets For pagination patterns, format selection, and MCP configuration, see `references/guide.md`.