We shipped an MCP server for WhatsApp link generation — no API key required

We shipped an MCP server for WhatsApp link generation — no API key required If you've ever needed an AI agent to validate a WhatsApp number, build a wa.me link, or generate a QR code on the fly, you've probably hand-rolled it: scrape a regex off Stack Overflow, write your own phone-format validator, maybe hit some undocumented endpoint. We got tired of watching that happen and shipped a small, open MCP server that does it directly. What it is WhatsUsernames.link already runs a free public REST API for validating WhatsApp usernames/phone numbers and generating wa.me links + QR codes. We just exposed the same logic over the Model Context Protocol, so Claude, and any other MCP client, can call it as native tools instead of you writing a fetch wrapper. Endpoint: https://whatsusernames.link/api/mcp No API key. No account. No signup form. Same open, IP-rate-limited model as the REST API (60 req/min for JSON tools, 20 req/min for QR generation, sliding window via Upstash Redis). The five tools Tool What it does validate_username Checks WhatsApp username (@username) format validate_phone Checks phone number format (8–15 digits, international) username_link Builds a wa.me link (+ short link) from a username, optional prefilled text phone_link Builds a wa.me link from a phone number, optional prefilled text qr_code Renders a QR code (PNG or SVG) for a wa.me link, custom size/colors Every tool wraps the exact same services/ and validate-* functions the REST API uses — there's no separate business logic to drift out of sync. If the REST endpoint says a number is valid, the MCP tool agrees, because it's the same code path. Connect it Drop this into your MCP client config: { "mcpServers": { "whatsusernames": { "url": "https://whatsusernames.link/api/mcp" } } } That's it. No stdio process to spawn, no local install — it's a stateless Streamable HTTP transport running on Vercel, same domain as the site. Why build this Two reasons. Practical: every agent that needs to hand a user a "message me on WhatsApp" link ends up reimplementing username/phone validation and QR generation, badly, from scratch. That's a solved problem now — call the tool instead. Strategic: we think a lot of AI-agent traffic is going to route through MCP servers the same way search traffic routes through APIs today. Being an early, documented, zero-friction MCP endpoint in the WhatsApp-tooling space is a cheap way to be the thing an agent reaches for, rather than something it reinvents. What's not in v0 Deliberately scoped down: No API keys, accounts, or paid tiers — same open rate-limited model as REST. No stdio/local package distribution — remote HTTP only, for now. No business-tier tools (bsuid parsing, webhook normalization) — those are more niche and will only get built if there's real demand for the current five. If you build something with it — or find an edge case it doesn't handle — we'd like to hear about it. WhatsUsernames.link is a free tool for validating WhatsApp usernames/numbers and generating wa.me links and QR codes. REST API and MCP server are both public and free to use.