API

Getting a token

Create one in an event's admin under Settings, API. The token is shown once, at creation. Only its hash is stored, so it cannot be recovered later, only revoked and replaced. A token reaches exactly the events the person who created it can open, on this API and over MCP alike.

export TOKEN=osk_...
curl -H "x-access-token: $TOKEN" "https://opensession.opensession.workers.dev/api/v1/events"

Shape of a response

Collections share one envelope. Single records come back as { "data": { ... } }.

{
    "data": [ ... ],
    "page": 1,
    "pageSize": 25,
    "total": 42,
    "totalPages": 2
  }

Paginate with page and pageSize, as query parameters or in a POST body. pageSize is capped at 100.

Errors

Errors are JSON with a stable code, never an HTML page.

{ "error": { "code": "invalid_token", "message": "That access token is not valid." } }

401 missing or invalid token, 404 unknown event or record, 405 wrong method, 422 the body was understood but rejected, 400 the body was not valid JSON.

Endpoints

• GET/api/v1/events

  List events, newest first.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/events?page=1&pageSize=25"

• GET/api/v1/event/:eventId

  One event, with submission, session, and public counts.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1"

• POST/api/v1/event/:eventId/sessions

  Search sessions. Filters go in the body: q, status, track, format, room, publicState, isAbstract, isDraft, scheduled.

  curl -X POST -H "x-access-token: $TOKEN" -H "content-type: application/json" \
    -d '{"q":"caching","status":"accepted","page":1,"pageSize":10}' \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions"

• GET/api/v1/event/:eventId/sessions

  The same collection without a body, for a plain paginated list.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions?pageSize=5"

• POST/api/v1/event/:eventId/sessions

  Create a session. A body carrying "create" is a write rather than a search.

  curl -X POST -H "x-access-token: $TOKEN" -H "content-type: application/json" \
    -d '{"create":{"title":"Observability on a Budget","abstract":"What you actually need.","trackId":3}}' \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions"

• GET/api/v1/event/:eventId/sessions/:sessionId

  One session with its speakers, track, format, room, and schedule.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions/1"

• PATCH/api/v1/event/:eventId/sessions/:sessionId

  Update a session. Accepts title, abstract, trackId, formatId, levelId, roomId, startsAt, endsAt, isDraft, publicState, and status or statusId.

  curl -X PATCH -H "x-access-token: $TOKEN" -H "content-type: application/json" \
    -d '{"status":"accepted","roomId":1,"startsAt":"2027-06-10T17:00:00Z","endsAt":"2027-06-10T17:45:00Z"}' \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions/1"

• DELETE/api/v1/event/:eventId/sessions/:sessionId

  Delete a session and its speaker links.

  curl -X DELETE -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/sessions/42"

• GET/api/v1/event/:eventId/contacts

  Everyone on the event: roster members and anyone on a session.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/contacts"

• GET/api/v1/event/:eventId/statuses

  Decision statuses, with their system keys.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/statuses"

• GET/api/v1/event/:eventId/tracks

  Tracks, in display order.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/tracks"

• GET/api/v1/event/:eventId/formats

  Formats, with their default durations.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/formats"

• GET/api/v1/event/:eventId/rooms

  Rooms, with capacities.

  curl -H "x-access-token: $TOKEN" \
    "https://opensession.opensession.workers.dev/api/v1/event/1/rooms"

MCP server

The same data over the Model Context Protocol, so an AI agent can run the conference program directly. Streamable HTTP transport at https://opensession.opensession.workers.dev/mcp, JSON-RPC 2.0 over a single POST. Every tool wraps the endpoints above; nothing here can do more than a token can do.

Authenticate with the same token, as an x-access-token header or as Authorization: Bearer. A request with neither gets a JSON-RPC error saying where to make one. Tools reach only the events the organizer who created the token can open, which is narrower than the REST endpoints above.

curl -X POST -H "x-access-token: $TOKEN" -H "content-type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"curl","version":"1"}}}' \
  "https://opensession.opensession.workers.dev/mcp"

Tools

• list_events

  Events this token can reach. Start here: it returns the eventId every other tool needs.

• search_sessions

  Search sessions by free text, status, track, format, room, and scheduled state.

• get_session

  One session with speakers, status, track, format, room, and schedule.

• update_session

  Change title, abstract, status, track, room, or start and end time.

• list_speakers

  The speaker roster with confirmation status and task and file counts.

• get_speaker

  One speaker with bio, sessions, and outstanding work.

• list_submissions_by_status

  The submissions queue for one status, with review score averages.

• accept_submission

  Set a submission to Accepted, or to the Accept Queue with queue: true.

• decline_submission

  Set a submission to Declined, with optional feedback stored on the record.

• get_agenda

  Rooms, days, scheduled and unscheduled sessions, and the double-booking conflicts.

• list_open_tasks

  Speaker tasks and file requests still outstanding, marked todo or overdue.

Decision tools change status only. Sending acceptance and decline email stays the explicit step under Communications, Send decisions, which is where the templates and the calendar attachment live.

Claude Code

One command, or the JSON block if you would rather edit the file.

claude mcp add --transport http opensession https://opensession.opensession.workers.dev/mcp \
  --header "x-access-token: $TOKEN"

{
  "mcpServers": {
    "opensession": {
      "type": "http",
      "url": "https://opensession.opensession.workers.dev/mcp",
      "headers": { "x-access-token": "osk_..." }
    }
  }
}

Codex

Add this to ~/.codex/config.toml.

[mcp_servers.opensession]
url = "https://opensession.opensession.workers.dev/mcp"
http_headers = { "x-access-token" = "osk_..." }