We launched whatsusernames-sdk: an npm client for our API

What we just shipped

After the free WhatsApp link API and the Business Platform (BSUID) API, one piece was missing: a ready-to-install client, so you don't have to hand-write fetch calls and error parsing every time you use the API from TypeScript or JavaScript.

It's called whatsusernames-sdk — open source (MIT), zero runtime dependencies, covering all 12 endpoints: the 7 link/QR/validation ones and the 5 Business Platform ones.

Install and use

npm install whatsusernames-sdk

import { createClient } from "whatsusernames-sdk";

const wa = createClient();

const { link, shortLink } = await wa.usernameLink({ username: "joao.silva" });
const qr = await wa.qr({ username: "joao.silva", format: "svg" });
// qr.body is a Uint8Array, qr.contentType is "image/svg+xml"

And for the Business Platform:

const parsed = await wa.business.bsuid.parse({ bsuid: "US.13491208655302741918" });
// { countryCode: "US", id: "13491208655302741918", isParent: false }

const contact = await wa.business.contact.resolve({ username: "joao.silva" });

const normalized = await wa.business.webhook.normalize(rawCloudApiWebhookPayload);

Why an SDK, not just the REST API

The REST API itself is already free and keyless — any fetch call reaches it. The SDK exists for anyone who wants:

• Ready-made TypeScript types for all 12 responses (UsernameLinkResult, ResolvedContact, NormalizedWebhook, and more), no hand-written interfaces.
• Consistent errors: any non-200 response throws WhatsUsernamesApiError with status, code, and message — one catch covers everything.
• Zero dependencies: uses only native fetch, works on Node 18+, browsers, and edge runtimes, without bloating your node_modules.
• ESM and CommonJS: import or require(), both work with no extra config.

Self-hosted

Running your own instance (or testing against localhost)? Point the client there:

const wa = createClient({ baseUrl: "http://localhost:3000" });

Open source

The SDK is on GitHub, MIT licensed: github.com/insidedcpulse-spec/whatsusernames-sdk. Issues and PRs welcome — it's the first concrete step toward making WhatsUsernames.link an open platform for developers, not just a closed product.

Full docs at whatsusernames.link/developers and the OpenAPI 3.1 specification.