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Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.

POST /cloud/v2/universes/{universe_id}:publishMessage — openapi

Publish Universe Message

Publishes a message to the universe's live servers.

Servers can consume messages via MessagingService.

Endpoint

Method: POST

Path: /cloud/v2/universes/{universe_id}:publishMessage

Servers:

Parameters

NameLocationRequiredDescription
universe_idpathtrueThe universe ID.
[
  {
    "name": "universe_id",
    "in": "path",
    "description": "The universe ID.",
    "required": true,
    "schema": {
      "type": "string"
    }
  }
]

Request Body

{
  "content": {
    "application/json": {
      "schema": {
        "$ref": "#/components/schemas/PublishUniverseMessageRequest"
      }
    }
  },
  "required": true
}

Responses

StatusDescription
200OK
{
  "200": {
    "description": "OK",
    "content": {}
  }
}

Authentication

{
  "security": [
    {
      "roblox-api-key": []
    },
    {
      "roblox-oauth2": []
    }
  ],
  "securitySchemes": {
    "roblox-api-key": {
      "type": "apiKey",
      "description": "A configurable key that allows granular access to Roblox resources. See https://create.roblox.com/docs/cloud/auth/api-keys for more information.",
      "name": "x-api-key",
      "in": "header"
    },
    "roblox-legacy-cookie": {
      "type": "apiKey",
      "description": "A browser cookie that represents the identity of a Roblox user. DO NOT SHARE THIS. Sharing this will allow someone to log in as you and to steal your Robux and items. We do not recommend using cookies to call endpoints. When possible, use API keys with the x-api-key header or OAuth 2.0 instead for authentication.",
      "in": "cookie",
      "name": ".ROBLOSECURITY"
    },
    "roblox-oauth2": {
      "type": "oauth2",
      "description": "Build or authorize apps to access Roblox resources. See https://create.roblox.com/docs/cloud/auth/oauth2-overview for more information.",
      "flows": {
        "authorizationCode": {
          "authorizationUrl": "https://apis.roblox.com/oauth/v1/authorize",
          "tokenUrl": "https://apis.roblox.com/oauth/v1/token",
          "refreshUrl": "https://apis.roblox.com/oauth/v1/token",
          "scopes": {}
        }
      }
    }
  }
}

Complete Operation Definition

{
  "tags": [
    "Universes"
  ],
  "summary": "Publish Universe Message",
  "description": "Publishes a message to the universe's live servers.\n\nServers can consume messages via\n[MessagingService](https://create.roblox.com/docs/reference/engine/classes/MessagingService).",
  "operationId": "Cloud_PublishUniverseMessage",
  "parameters": [
    {
      "name": "universe_id",
      "in": "path",
      "description": "The universe ID.",
      "required": true,
      "schema": {
        "type": "string"
      }
    }
  ],
  "requestBody": {
    "content": {
      "application/json": {
        "schema": {
          "$ref": "#/components/schemas/PublishUniverseMessageRequest"
        }
      }
    },
    "required": true
  },
  "responses": {
    "200": {
      "description": "OK",
      "content": {}
    }
  },
  "x-roblox-engine-usability": {
    "apiKeyWithHttpService": true
  },
  "x-roblox-rate-limits": {
    "description": "Messaging Service requests are subject to additional throttling limits described in the [Open Cloud guide for Messaging Service](https://create.roblox.com/docs/cloud/guides/usage-messaging#limits).",
    "perApiKeyOwner": {
      "period": "MINUTE",
      "maxInPeriod": 5000
    },
    "perOauth2Authorization": {
      "period": "MINUTE",
      "maxInPeriod": 5000
    }
  },
  "x-roblox-scopes": [
    {
      "name": "universe-messaging-service:publish"
    }
  ],
  "x-roblox-docs": {
    "category": "Universes and places",
    "methodProperties": {
      "scopes": [
        "universe-messaging-service:publish"
      ]
    },
    "resource": {
      "$ref": "#/components/schemas/Universe",
      "name": "Universe"
    }
  },
  "x-roblox-stability": "STABLE",
  "security": [
    {
      "roblox-api-key": []
    },
    {
      "roblox-oauth2": []
    }
  ],
  "externalDocs": {
    "url": "https://create.roblox.com/docs/cloud/reference/features/universes#Cloud_PublishUniverseMessage"
  }
}