Request Format

Clients send JSON text frames to subscribe, unsubscribe, and answer heartbeats.

Message structure (client to server)

{
  "method": "subscribe",
  "requestId": 1,
  "params": ["predictOrderbook/123"]
}

Field	Type	Required	Description
`method`	string	Yes	`subscribe`, `unsubscribe`, or `heartbeat`.
`requestId`	number	For `subscribe` / `unsubscribe`	A unique non-negative integer you choose, echoed back on the matching response so you can correlate it.
`params`	string[]	For `subscribe` / `unsubscribe`	The topic to act on. One topic per request — only the first entry is used.
`data`	any	For `heartbeat`	The exact timestamp received from the server's heartbeat.

{ "method": "subscribe", "requestId": 1, "params": ["predictMarketStatus/123"] }

The server replies with a response message (type: "R") carrying the same requestId. For snapshot-backed topics, a snapshot message (type: "M") is also pushed immediately, followed by live updates. Subscribing again to a topic you already hold is a no-op that simply re-acknowledges.

Unsubscribe

{ "method": "unsubscribe", "requestId": 2, "params": ["predictMarketStatus/123"] }

Unsubscribing always acknowledges successfully, whether or not the subscription existed.

Heartbeat

Answer each server heartbeat by echoing its timestamp. The heartbeat request has no requestId or params:

{ "method": "heartbeat", "data": 1736696400000 }

See Heartbeats for the full mechanism.

Errors

A malformed or rejected request is answered with a response message whose success is false and whose error.code is one of:

Code	Meaning
`invalid_json`	The message is not valid JSON. Returned with `requestId: -1`.
`invalid_topic`	The topic is malformed, unknown, or has an invalid parameter.
`invalid_credentials`	The wallet JWT is invalid, expired, or revoked.
`internal_server_error`	An unexpected server error occurred.

(Authentication failures during the initial handshake are returned as HTTP status codes, not as these JSON errors.)

Message structure (client to server)#

Subscribe#

Unsubscribe#

Heartbeat#

Errors#

Message structure (client to server)

Subscribe

Unsubscribe

Heartbeat

Errors