history:redo

Redo a previously undone history batch via WebSocket.
Equivalent to POST /api/history/redo in REST.

Each redo re-applies the operations from the batch that was previously undone.
The undone batch is linked to the redo batch via RedoOf / RedoneBy.

Rate limits

• Maximum 3 redo requests per 10 seconds per user.

---

Client → Server history:redo

{
  "batchId": "f1b4232e-7c9f-4c12-9f0a-17cc0012a511"
}

Parameters:

• batchId (UUID, required) — identifier of the undone batch to redo.
  Must refer to a batch that was previously undone by this user.

---

Success (ack)

{
  "ok": true,
  "batchId": "d2a77b31-21c5-4f9b-99ce-41078551df33",
  "redoOf": "f1b4232e-7c9f-4c12-9f0a-17cc0012a511",
  "diff": {
    "nodes": [
      { "id": "uuid", "title": "Restored title", "version": 6 }
    ],
    "links": []
  },
  "trace_id": "b9c72e551bfa"
}

Field reference

Field	Description
batchId	ID of the newly created redo batch
redoOf	ID of the undone batch being redone
diff	Diff re-applied to client state
trace_id	Internal diagnostic identifier for tracing

---

Error (ack)

{
  "ok": false,
  "error": "conflict.not_undone",
  "message": "Batch is not in undone state",
  "trace_id": "b9c72e551bfa"
}

Errors:

Code	Meaning
bad_request.missing_batchId	Missing required field
not_found.batch	Batch not found or inaccessible
conflict.not_undone	Batch is not in undone state
forbidden.access_denied	User lacks permission
internal.exception	Internal server error

---

Example (JavaScript)

socket.emit("history:redo", { batchId: "f1b4232e-7c9f-4c12-9f0a-17cc0012a511" }, (ack) => {
  if (!ack.ok) return console.error("Redo failed:", ack);
  console.log("Redo successful, new batch:", ack.batchId);
});

---

Example (Python)

import socketio

sio = socketio.Client()

@sio.event
def connect():
    print("connected")
    sio.emit("history:redo", {"batchId": "<uuid>"}, callback=lambda ack: print("ACK:", ack))

sio.connect("https://synaptask.space",
            headers={"Authorization": "Bearer <API_TOKEN>"},
            transports=["websocket"])
sio.wait()

See also history:undo