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Alex Spinov
Alex Spinov

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npm Registry Has a Free API — Query 2M+ JavaScript Packages Without Authentication

#npm #api #javascript #webdev

npm Is Not Just a CLI

The npm registry exposes a free JSON API. No API key, no OAuth, no rate limits for reasonable usage. Every package on npm has a JSON endpoint.

Get Package Metadata 

const res = await fetch("https://registry.npmjs.org/express");
const pkg = await res.json();

console.log(`${pkg.name} — ${pkg.description}`);
console.log(`Latest: ${pkg["dist-tags"].latest}`);
console.log(`Versions: ${Object.keys(pkg.versions).length}`);
console.log(`License: ${pkg.license}`);
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Get Specific Version 

const res = await fetch("https://registry.npmjs.org/react/19.0.0");
const version = await res.json();

console.log(`Dependencies:`, Object.keys(version.dependencies || {}));
console.log(`Size: ${version.dist.unpackedSize} bytes`);
console.log(`Tarball: ${version.dist.tarball}`);
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Get Download Counts 

// Last week downloads
const res = await fetch("https://api.npmjs.org/downloads/point/last-week/express");
const data = await res.json();
console.log(`${data.package}: ${data.downloads.toLocaleString()} downloads/week`);

// Daily breakdown
const range = await fetch("https://api.npmjs.org/downloads/range/last-month/express");
const daily = await range.json();
daily.downloads.forEach(d => console.log(`${d.day}: ${d.downloads.toLocaleString()}`));
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Compare Packages 

async function comparePackages(names) {
  const results = await Promise.all(
    names.map(async name => {
      const [meta, downloads] = await Promise.all([
        fetch(`https://registry.npmjs.org/${name}`).then(r => r.json()),
        fetch(`https://api.npmjs.org/downloads/point/last-week/${name}`).then(r => r.json())
      ]);
      return {
        name,
        version: meta["dist-tags"].latest,
        weekly: downloads.downloads
      };
    })
  );
  results.sort((a, b) => b.weekly - a.weekly);
  results.forEach(r => 
    console.log(`${r.name.padEnd(20)} v${r.version.padEnd(10)} ${r.weekly.toLocaleString()}/week`)
  );
}

await comparePackages(["express", "fastify", "hono", "koa", "nest"]);
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Search Packages 

const res = await fetch("https://registry.npmjs.org/-/v1/search?text=web+scraping&size=5");
const data = await res.json();

data.objects.forEach(obj => {
  const p = obj.package;
  console.log(`${p.name} — ${p.description?.slice(0, 60)}`);
});
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Real Use Cases

  1. Dependency dashboards — monitor all your deps for new versions
  2. Security scanning — check package sizes for supply chain attacks
  3. Ecosystem analytics — track framework adoption trends
  4. CI/CD — auto-detect outdated packages in PRs
  5. Tech radar — compare alternatives by download trends

More API tutorials | GitHub

More from me: 10 Dev Tools I Use Daily | 77 Scrapers on a Schedule | 150+ Free APIs

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