Whenna for agents & developers

Everything a human does by tapping, an AI agent can do with one tool call — create a plan, mark availability, read the best time, attach an encrypted video room, lock it in, and restart the group for next time. No API keys.

Agent-to-agent: any number of assistants can work the same plan link — each marks availability for the human it represents, and whenna_get_plan returns a negotiation brief (state + suggested_next_step) that always says what to do next, so no assistant has to infer the protocol.

MCP: https://whenna.com/mcp llms.txt openapi.json

MCP (recommended)

Streamable-HTTP, stateless, JSON-RPC 2.0, no auth. Add it to any MCP-capable agent (Claude, ChatGPT, Cursor, …) as a remote server with the URL above.

curl -X POST https://whenna.com/mcp -H 'Content-Type: application/json' -d '{
  "jsonrpc":"2.0","id":1,"method":"tools/call","params":{
    "name":"whenna_create_plan","arguments":{
      "title":"Team dinner","days":["2026-07-10","2026-07-11"],
      "start_hour":18,"end_hour":22,"timezone":"America/Chicago"}}}'

Tool	Does
`whenna_create_plan`	Create a plan → share `url` + private `creator_key`
`whenna_get_plan`	Full state + negotiation brief: `state`, who answered, best-block coverage, `suggested_next_step`
`whenna_mark_availability`	Set a participant's free ranges (`{day, from, to}`); empty = can't-make; `withdraw` removes; skipped ranges reported with reasons
`whenna_best_times`	Ranked blocks where the most people are free, with names
`whenna_lock_time`	Confirm the final time (creator_key) → calendar links for everyone
`whenna_set_place`	Set a place, or `video_call:true` to attach a built-in end-to-end-encrypted video room (link lands on every calendar)
`whenna_plan_next`	Group memory: after the event, restart the group — clones the setup, proposes next dates, notifies opted-in members

Read-only tools are annotated; initialize returns full instructions. All 7 tools are also published to the official MCP registry as com.whenna/whenna.

REST

Endpoint	Does
`POST /api/meetings`	Create → `{id, creatorKey}`
`GET /api/meetings/:id`	Plan state (JSON)
`PUT /api/meetings/:id/availability`	Set someone's slots
`GET /api/meetings/:id/best`	Ranked best time blocks
`PUT /api/meetings/:id/final`	Lock / unlock the final time
`PUT /api/meetings/:id/where`	Set the place, or `{video:true}` for the encrypted video room
`PUT /api/meetings/:id/groupsub`	Opt an email in to hear when the group plans again
`POST /api/meetings/:id/rebook`	Start the group's next plan from a finished one (creatorKey)
`GET /api/meetings/:id/event.ics`	Calendar file (TZID-correct)
`GET /api/meetings/:id/stream`	Live updates (SSE)

Video calls

Every plan can meet on a built-in, end-to-end-encrypted group video room at https://whenna.com/o/<id>/call — mesh WebRTC (media is device-to-device, never through the server), no app and no accounts. Attach it with whenna_set_place video_call:true or PUT /where {video:true}; the room link then rides on everyone's calendar invite.

Humans answer at https://whenna.com/o/<id> — send them the link and the two worlds meet on the same live grid.