Upgrading from 3.x? See the migration guide (also on the

docs site) — it maps

common 3.x calls and workflows to their 4.x equivalents and ships a

codemod that automates most of the work.

Requirements

• SDK consumers: Node.js >= 20 — the REST transport uses the platform-global

• Repository contributors: Node.js >= 24 (see .nvmrc). Build, docs,

• Strict Node TypeScript projects may omit DOM libs; the REST declarations are

Runtime compatibility

| Runtime | REST / fetch-based SSE | WebSockets | Notes | | --- | :---: | :---: | --- | | Node.js >= 20 | ✅ | ✅ | Primary target. | | Bun | ✅ | ✅ | Node-compatible (ws runs). | | Deno | ✅ | ❌ | Root auto-resolves to the REST build via the deno export condition. | | Cloudflare Workers / workerd | ✅ | ❌ | Root auto-resolves to the REST build (workerd / worker). | | Vercel Edge | ✅ | ❌ | Root auto-resolves to the REST build (edge-light). | | Browser | ✅ | ❌ | Resolves to the REST build (browser). Not recommended — see caveat. |

Legend: ✅ supported · ❌ not supported.

• WebSocket streaming is Node/Bun only. Those clients use Node-compatible

• Browser: technically works, but discouraged. Calling Alpaca directly from a

ESM and CJS module formats, edge export conditions, and the REST-only entrypoint are documented on the docs site: Runtime & module compatibility.

Install

npm install @alpacahq/alpaca-trade-api

Quick start

import { Alpaca } from "@alpacahq/alpaca-trade-api";
const alpaca = new Alpaca({
  keyId: process.env.APCA_API_KEY_ID,
  secret: process.env.APCA_API_SECRET_KEY,
  paper: true, // default; set false for live trading
});
const account = await alpaca.trading.account.getAccount();
const price = await alpaca.marketData.getLatestPrice("AAPL");
const bars = alpaca.marketData.stockStream({ feed: "iex" });
bars.onBar((b) => console.log(b.symbol, b.close));
bars.onConnect(() => bars.subscribeForBars(["AAPL", "MSFT"]));
bars.connect();

Server-Sent Events

The facade provides typed async SSE subscriptions with cancellation, reconnection, and Last-Event-ID resumption:

const controller = new AbortController();
const activities = await alpaca.trading.subscribeActivities(
  {},
  { signal: controller.signal },
);
try {
  for await (const activity of activities) {
    console.log(activity.activityType, activity.details);
  }
} finally {
  activities.close();
}

Corporate-action mutations are available from alpaca.marketData.subscribeCorporateActions(). The longer generated operation names remain available under trading.events and marketData.corporateActions; see the streaming guide.

Documentation

The documentation site is the canonical source for workflows, conventions, and curated API discovery. Installed TypeScript declarations remain authoritative for exact signatures and models. Key guides:

• Getting started
• Trading
• Market data
• Streaming
• Authentication
• Resilience & configuration
• Pagination
• Values & types
• Testing your integration
• Runtime & module compatibility
• Examples
• Migration from 3.x
• Migration overview
• Migration from 4.x to 5.0
• API reference
• AI coding guidance — choose either equivalent format:

Build from source

npm install      # also builds via the prepare script
npm run build    # tsup -> dual ESM + CJS in dist/
npm run typecheck
npm run lint
npm test

Runnable examples live in examples/. To preview the docs site locally:

npm --prefix docs install   # first time only
npm --prefix docs start     # http://localhost:3000/alpaca-trade-api-js/

Releases

Stable versions are published to npm on the latest dist-tag. See CHANGELOG.md for release notes.

Support

• Library / SDK issues: Bugs, feature requests, or questions specific to this

• General Alpaca support & API discussion: Account questions, platform issues,

• Slack community: Chat with other developers and the Alpaca community on

Contributing

Contributions are welcome. See CONTRIBUTING.md for setup, generated-code boundaries, documentation workflow, and release notes conventions.