servo-fetch

Node.js bindings for servo-fetch — fetch, render, and extract web content with an embedded Servo browser engine.

• No Chromium — single self-contained binary, bundled in the package
• JavaScript execution — full Servo engine with SpiderMonkey
• Schema extraction — declarative CSS-selector → structured JSON, no LLM
• Streaming crawl — for await over pages as they complete
• Typed — first-class TypeScript types, ESM and CommonJS

Install

npm install servo-fetch

The prebuilt binary for your platform is selected automatically through optionalDependencies. Supported targets: macOS (arm64, x64), Linux glibc (x64, arm64), Windows x64.

Quick Start

import { fetch, extract, crawl, map, screenshot } from "servo-fetch";

const md = await fetch("https://example.com"); // readable Markdown

const article = await extract("https://example.com"); // Readability data
console.log(article.title, article.textContent);

for await (const page of crawl("https://docs.example.com", { limit: 50 })) {
  if (page.ok) console.log(page.url, page.title);
}

const urls = await map("https://example.com"); // sitemap discovery, no render
const png = await screenshot("https://example.com", { fullPage: true });

Schema Extraction

import { extractSchema } from "servo-fetch";

const products = await extractSchema("https://shop.example.com", {
  baseSelector: ".product",
  fields: [
    { name: "title", selector: "h2", type: "text" },
    { name: "price", selector: ".price", type: "text" },
    { name: "url", selector: "a", type: "attribute", attribute: "href" },
  ],
});

CLI

The bundled binary is also runnable directly:

npx servo-fetch "https://example.com"
npx servo-fetch "https://example.com" --format png -o page.png

API

| Function | Returns | CLI equivalent | | --- | --- | --- | | fetch(url, opts?) | Promise<string> (Markdown) | default | | fetchHtml(url, opts?) | Promise<string> | --format html | | fetchText(url, opts?) | Promise<string> | --format text | | extract(url, opts?) | Promise<Article> | --format json | | extractSchema<T>(url, schema, opts?) | Promise<T> | --schema | | screenshot(url, opts?) | Promise<Buffer> | --format png | | evaluate(url, expr, opts?) | Promise<string> | --js | | batchFetch(urls, opts?) | Promise<BatchResult[]> | parallel fetch | | crawl(url, opts?) | AsyncGenerator<CrawlResult> | crawl | | crawlAll(url, opts?) | Promise<CrawlResult[]> | crawl | | map(url, opts?) | Promise<MappedUrl[]> | map | | version() | Promise<string> | --version |

Single-page calls accept { timeout, settle, userAgent, cookiesFile, headers, selector, visibility, signal }; crawl and map also accept headers.

Calls share one persistent servo-fetch process (warm engine), spawned on first use; shutdown() stops it.

Env: SERVO_FETCH_BINARY_PATH overrides binary resolution; SERVO_FETCH_ALLOW_PRIVATE=1 relaxes the SSRF guard for loopback/private addresses (trusted environments only).

Develop

Requires pnpm.

pnpm install
pnpm run build      # tsdown
pnpm test           # vitest
pnpm run typecheck  # tsc --noEmit
pnpm run lint       # biome (lint + format + import sort)