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Node.js & Viam's TypeScript SDK

This document contains detailed instructions on including Viam in your Node.js project. For a runnable example, see the examples directory.

Requirements

This document assumes you already have Node.js >= version 20 installed. If not, follow the instructions provided by Node.js.

Dependencies

In addition to the Viam SDK, the following direct dependencies are requires:

  • @connectrpc/connect-node
  • node-datachannel

You can use either Yarn or NPM to install the dependencies. This document will use NPM, but either will work.

npm install @viamrobotics/sdk @connectrpc/connect-node node-datachannel

Polyfills

Using the SDK with Node.js also requires the use of some polyfills. In your application's entrypoint (main.ts, index.ts, or something similar), you will need to register those polyfills:

// main.ts

const wrtc = require('node-datachannel/polyfill');
for (const key in wrtc) {
  (global as any)[key] = (wrtc as any)[key];
}

Transport

Communicating with your Viam machine in Node.js requires the use of a custom transport. In your app's entrypoint, you will also need to register the custom transport:

// main.ts

const connectNode = require('@connectrpc/connect-node');
globalThis.VIAM = {
  GRPC_TRANSPORT_FACTORY: (opts: any) =>
    connectNode.createGrpcTransport({ httpVersion: '2', ...opts }),
};

Using the SDK

To use the SDK, you can use similar instructions to those found on the documentation site. Below is an example of how you could use the SDK to display a list of resources on the connected device:

// main.ts

const VIAM = require('@viamrobotics/sdk');
const wrtc = require('node-datachannel/polyfill');
const connectNode = require('@connectrpc/connect-node');
globalThis.VIAM = {
  GRPC_TRANSPORT_FACTORY: (opts: any) =>
    connectNode.createGrpcTransport({ httpVersion: '2', ...opts }),
};
for (const key in wrtc) {
  (global as any)[key] = (wrtc as any)[key];
}

async function connect() {
  const host = process.env.HOST;
  const apiKeyId = process.env.API_KEY_ID;
  const apiKeySecret = process.env.API_KEY_SECRET;
  if (!host) {
    throw new Error('must set HOST env var');
  }
  if (!apiKeyId) {
    throw new Error('must set API_KEY_ID env var');
  }
  if (!apiKeySecret) {
    throw new Error('must set API_KEY_SECRET env var');
  }

  const client = await VIAM.createRobotClient({
    host,
    credentials: {
      type: 'api-key',
      authEntity: apiKeyId,
      payload: apiKeySecret,
    },
    signalingAddress: 'https://app.viam.com:443',
    iceServers: [{ urls: 'stun:global.stun.twilio.com:3478' }],
  });

  console.log(await client.resourceNames());
}

connect().catch((e) => {
  console.error('error connecting to machine', e);
});

In the above example, it is assumed that certain environment variables are set (HOST, API_KEY_ID, and API_KEY_SECRET). You can set those in the process or have a .env file set them automatically. If you use a .env file, be sure to exclude it from version control.

In your terminal, you can run:

npx tsc && node --env-file=.env main.js