Developers & API

What's Up In is free to use from code and from AI agents: no account, no key, no sign-up. Everything below is read-only. Ways in: the MCP server for AI assistants and agents, the same search as an A2A agent, and a small HTTP API for the cross-city search. Each city’s own site has its own MCP server and full event files too.

MCP server (recommended for agents)

Endpoint	`https://whatsupin.ai/mcp`
Transport	Streamable HTTP (POST JSON-RPC); protocol 2025-11-25, 2025-06-18 or 2025-03-26
Auth	None
Tools	`search_events`, `list_upcoming`, `get_event`, `get_city` (one city, by `city`); `search_across_cities`; `list_cities`
Server card	`/.well-known/mcp/server-card.json` (also `/mcp/server-card`)
Registry	`ai.whatsupin/events` in the official MCP registry

Add it to Claude Code:

claude mcp add --transport http whatsupin https://whatsupin.ai/mcp

Claude, ChatGPT and other apps: setup guide for AI assistants.

A2A agent

The MCP server’s tools over the Agent2Agent protocol, for agent platforms that speak A2A. Send a question as a text part, or a JSON data part naming a tool and its arguments; every message gets a finished task back with a short text answer and the full JSON.

Endpoint	`https://whatsupin.ai/a2a`
Binding	JSON-RPC: `SendMessage` (A2A 1.0, header `A2A-Version: 1.0`) or `message/send` (0.3)
Auth	None
Agent card	`/.well-known/agent-card.json`
Not offered	Streaming, push notifications, stored tasks (`GetTask` answers “not found”)

curl https://whatsupin.ai/a2a -H "content-type: application/json" -H "A2A-Version: 1.0" -d '{"jsonrpc":"2.0","id":1,"method":"SendMessage","params":{"message":{"messageId":"1","role":"ROLE_USER","parts":[{"text":"free comedy in Boston this weekend"}]}}}'
curl https://whatsupin.ai/a2a -H "content-type: application/json" -H "A2A-Version: 1.0" -d '{"jsonrpc":"2.0","id":2,"method":"SendMessage","params":{"message":{"messageId":"2","role":"ROLE_USER","parts":[{"data":{"tool":"search_across_cities","arguments":{"query":"Khruangbin"}}}]}}}'

HTTP API

Cross-city search for performers, festivals, conferences, big shows, games and races. JSON out. Full spec: /openapi.json (OpenAPI 3.1).

curl "https://whatsupin.ai/api/search?q=khruangbin"
curl "https://whatsupin.ai/api/search?kind=festival,conference&city=boston,seattle&from=2026-11-01"

`GET /api/search`	`q`, `kind` (act, festival, major, conference, big_show, game, race), `city`, `from`, `to`, `limit`, `neighborhood`, `near` (“lat,lon”), `radius_km`, `trip`
`GET /cities.json`	Every city: slug, name, status (live, beta, soon) and its site
Per city	Each city site serves `/openapi.json`, `/data/events.json`, `/mcp` and `/llms.txt`; `list_cities` or `/cities.json` gives the addresses

Limits and errors

40 searches a minute per IP address on /api/search; MCP calls have their own per-minute budget. Over the limit you get HTTP 429 with a Retry-After header in seconds: wait that long, then try again.
Errors are JSON, {"error": "…"}, saying what was wrong with the request (for example a missing query or a bad near).
Results are cached at the edge for a few minutes, so a repeated query is cheap.

Terms in one line

Use it to answer one person’s question, credit What's Up In, and keep each event’s link to its original listing. Bulk copying needs written permission: see the terms or write to [email protected].

Machine-readable files

/llms.txt: guide for AI assistants, with every city’s site and MCP address
/index.md: the home page as markdown (also returned for Accept: text/markdown)
/.well-known/ai-catalog.json (and ard.json): catalog of the MCP server, API and skill
/.well-known/api-catalog: RFC 9727 API catalog
/.well-known/agent-skills/index.json: an agent skill describing when and how to use What's Up In
/.well-known/mcp.json: short MCP manifest
/.well-known/agent-card.json: A2A agent card

Questions or problems: [email protected].