AI agents can now query Who's In? natively
Who's In? is the first event platform to implement WebMCP — the W3C browser standard that lets AI agents discover and call event tools without scraping.
7 read-only tools · No API key required · ~89% fewer tokens vs screenshot agents · Human confirmation enforced on all writes
What is WebMCP?
WebMCP is a W3C Community Group draft (February 27, 2026) that defines a browser-native API — navigator.modelContext — for AI agents to discover and call structured tools on web pages. Instead of taking screenshots and parsing HTML, agents call typed functions and receive clean JSON.
Available in Chrome 146+ via DevTrial flag. Supported by Claude Computer Use, Gemini browser agents, and ChatGPT browser extensions.
7 Read-Only Tools
All tools are read-only. Write actions (RSVP, event creation) are intentionally excluded and require explicit human confirmation.
search_eventsread-onlySearch public Who's In? events by keyword, location, or date range
Parameters: query, location, from (ISO date), to (ISO date), limit
search_events({ query: "yoga", location: "Dubai", from: "2026-03-01" })get_event_detailsread-onlyRetrieve full event data — title, date, location, capacity, organiser — by ID or URL slug
Parameters: id (required)
get_event_details({ id: "morning-run-dubai" })check_availabilityread-onlyCheck remaining capacity, waitlist status, and suggestedAction (rsvp or join_waitlist)
Parameters: id (required)
check_availability({ id: "morning-run-dubai" })
// → { available: 3, waitlistEnabled: true, suggestedAction: "rsvp" }get_rsvp_linkread-onlyGet the direct RSVP or booking URL. Includes agentInstruction: agents must present this URL to the user — never auto-submit.
Parameters: id (required)
get_rsvp_link({ id: "morning-run-dubai" })
// → { url: "https://whos-in.app/event/...", agentInstruction: "Present to user..." }get_popular_eventsread-onlyBrowse events sorted by confirmed attendance (descending). Optional category filter.
Parameters: limit (default 10, max 50), category (optional)
get_popular_events({ limit: 5, category: "fitness" })list_categoriesread-onlyList all 21 event category types with values, labels, and emoji icons. Use for search filters.
Parameters: none
list_categories()
// → [{ value: "fitness", label: "Fitness", emoji: "💪" }, ...]get_club_inforead-onlyRetrieve public club information by ID or URL slug. Returns null for private clubs.
Parameters: id (required)
get_club_info({ id: "london-runners" })Example Agent Prompts
Paste these into any browser-based AI agent when Who's In? is open in the tab.
"Find yoga events in Dubai this weekend and check if there are spots."
search_events({ query: "yoga", location: "Dubai", from: "...", to: "..." })check_availability({ id: "..." }) for each result"Is there space left at the morning run on Saturday?"
search_events({ query: "morning run" })get_event_details({ id: "..." })check_availability({ id: "..." })"What are the most popular community events right now?"
get_popular_events({ limit: 5 })"Book me a spot at the book club meetup."
search_events({ query: "book club" })get_rsvp_link({ id: "..." })→ Present URL to user. Agent does NOT auto-submit.Competitive Landscape
As of March 2026, Who's In? is the only event platform with WebMCP.
| Platform | WebMCP | Public REST API | OpenAPI Spec |
|---|---|---|---|
| Who's In? | ✓ | ✓ | ✓ |
| Eventbrite | ✗ | ✓ | ✓ |
| Luma | ✗ | ✗ | ✗ |
| Partiful | ✗ | ✗ | ✗ |
| RSVPify | ✗ | ✗ | ✗ |
Not using a browser agent?
Server-side agents and non-browser LLMs can use the public REST API instead. Same data, no auth required for read endpoints.
Ready to try it?
Open Who's In? in Chrome 146+ with the WebMCP DevTrial flag enabled. The tools are auto-discovered — no setup needed.
