Messages and reactions API

6 endpoints. See Send a message via the API for the prose-driven version.

Messages#

Method	Path	Purpose
`GET`	`/v1/rooms/{room_id}/messages`	List messages with pagination by `stream_position`.
`POST`	`/v1/rooms/{room_id}/send`	Create a new event.
`POST`	`/v1/rooms/{room_id}/events/{event_id}/edit`	Edit an existing event (sender only, default 24h window).
`POST`	`/v1/rooms/{room_id}/events/{event_id}/redact`	Redact (own, or `power_level ≥ 50`).

GET /v1/rooms/{room_id}/messages#

Query params:

limit (default 50, max 200).
from — stream position to start from.
direction — back (older) or forward (newer); default back.

Response:

json
{
  "data": [
    {
      "id": "evt-…",
      "room_id": "room-…",
      "sender_id": "5e4d…",
      "event_type": "swp.room.message",
      "content": { "msgtype": "swp.text", "body": "Hello" },
      "stream_position": 12345,
      "origin_ts": 1778939467,
      "created_at": "2026-05-17T11:00:00Z",
      "edited_at": null,
      "redacted_at": null
    }
  ],
  "meta": { "has_more": true, "next_cursor": "12300" }
}

POST /v1/rooms/{room_id}/send#

Body fields:

content (object, required).
event_uuid (string, optional; for idempotency).
as_participant_id (string, optional; bot-send-on-behalf, requires power_level ≥ 100).

See Send a message via the API for content shapes.

POST /v1/rooms/{room_id}/events/{event_id}/edit#

json
{ "content": { "msgtype": "swp.text", "body": "Corrected" } }

Edits expire 24h after creation by default. The original content is preserved in event.original_content.

POST /v1/rooms/{room_id}/events/{event_id}/redact#

json
{ "reason": "Posted in the wrong room" }

Body of the event is wiped; metadata + event id remain. Cannot be undone.

Reactions#

Method	Path	Purpose
`POST`	`/v1/rooms/{room_id}/events/{event_id}/reaction`	Add a reaction.
`DELETE`	`/v1/rooms/{room_id}/events/{event_id}/reaction`	Remove your reaction.

Body for POST:

json
{ "emoji": "🚀" }

Each (event, sender, emoji) is a unique reaction — re-posting the same emoji from the same sender is a no-op.

Errors#

SW_EVENT_NOT_FOUND — event id doesn't exist.
SW_EVENT_TOO_OLD_TO_EDIT — edit past the window.
SW_REDACT_FORBIDDEN — not yours and you lack power level.
SW_RATE_LIMIT_EXCEEDED — over the tenant's send rate.
SW_CONTENT_TOO_LARGE — content exceeds 64 KB.