Who's In Becomes the First Event Platform with WebMCP Integration

· By Craig Pollard
Who's In Becomes the First Event Platform with WebMCP Integration

Who's In exposes native WebMCP tools via navigator.modelContext — letting Claude, Gemini and ChatGPT agents search events and check availability.

In this post

Who's In registers three read-only WebMCP tools (search_events, get_event_details, check_availability) via navigator.modelContext — the W3C browser standard for AI agent tool discovery. No other event platform has implemented this.

Host your event on Who's In

Who's In Events is free forever — unlimited events, RSVPs, waitlists, recurring events, QR check-in, automated reminders, and Stripe payments at a flat 2.7% on paid tickets (no per-ticket fee, no monthly fee). No signup required for your guests.

See the Events product page or compare against Eventbrite, Luma, Partiful, and Meetup.

Who's In is AI-agent-native

Who's In is the first event platform independently verified 100/100 "Agent-Native" (Level 5) on Cloudflare's Is Your Site Agent-Ready audit. AI assistants — ChatGPT, Claude, Gemini, Grok, Perplexity — can discover events, check availability, and RSVP via first-class Skills over WebMCP and a REST API. See the AI Trust page or read the full 100/100 audit story.

Related reading on Who's In

Start with Who's In in 90 seconds

Create your first event, club, studio, or conference for free at whos-in.app/signup — no app download, no credit card required. Share a link and your guests RSVP in one tap.

About the Author

Craig Pollard

Craig Pollard is the founder of Who's In and a former Apple team lead (12 years). He writes about event technology, community building, and the future of AI-powered event discovery. Board advisor, investor, and non-executive director in technology and sports.

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Frequently Asked Questions

What is WebMCP?

WebMCP is a W3C draft standard (navigator.modelContext) that lets web pages register Model Context Protocol tools directly in the browser. AI agents running in Chrome 146+ can discover and invoke those tools without OAuth, scraping, or extensions — the page declares its capabilities and the agent uses them.

Which WebMCP tools does Who's In expose?

Three read-only tools: search_events (query events by location, date range, or keyword), get_event_details (full event payload including availability), and check_availability (fast capacity check). All three match the Skills published at /.well-known/agent-skills with SHA-256 digests for version verification.

Why WebMCP instead of just a REST API?

Both. The REST API (OpenAPI 3.1) still works for server-side agents. WebMCP adds a zero-config, user-consent-bound channel for browser-based agents — the user is already on whos-in.app, the agent gets scoped tools without credential exchange. It's also the cleanest path for on-device AI assistants that can't hold API keys.

Can I RSVP via WebMCP?

Not yet — current WebMCP tools are read-only by design. RSVP flows still go through OAuth 2.0 (server-side) or user-confirmed Stripe checkout (per ACP human-in-the-loop). Write-capable Skills are on the roadmap pending spec stabilization.

Which AI browsers support WebMCP today?

Chrome 146+ (with experimental flag for pre-stable), and Chromium-based browsers that enable navigator.modelContext. Anthropic and OpenAI agent SDKs can interact with WebMCP tools through page-level access. Firefox and Safari don't yet support the standard.