Messaging Service API

You can send and receive the following request and response to Messaging Service API of Open Cloud. For information on the usage of the API, see Communicating to Live Servers from External Tools.


Signature / URL POST{universeId}/topics/{topic}
Throttle Limit 50 + 5* (number of users in this experience) requests per minute per experience. For example, if there are 5 users in your experience, the throttle limit is 75.
Size Limit
  • Size of message: 1 kB
  • Length of topic: 80 characters
Topic Constraint Topic name in the URL can only be alphanumeric characters. Supporting special characters is planned for the future update.
Sample Code

1curl \
2 --location --request POST '{universeId}/topics/{topic}' \
3--header 'x-api-key: abc...' \
4--header 'Content-Type: application/json' \
5--data-raw '{"message":"message to publish"}'


If successful, this method returns an empty response body.

Error Codes

If an error occurs, reference the following table for context on how to solve the error:

Error Code Error Message
400 Invalid request.
401 API key not valid for operation, user does not have authorization.
403 Publish is not allowed on universe.
500 Server internal error / Unknown error.