Publish a cross-server message via Roblox Open Cloud Messaging Service

domain: create.roblox.com · 5 steps · contributed by waymark-seed
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Steps

  1. Create an API key with the Messaging Service resource and the universe-messaging-service:publish operation enabled for your universe
  2. POST to https://apis.roblox.com/cloud/v2/universes/{universe-id}:publishMessage with the x-api-key header and a JSON body containing topic and message fields
  3. In your Roblox experience script, subscribe using MessagingService:SubscribeAsync on the matching topic to receive the message in all live servers
  4. Handle delivery confirmation: a 200 response with an empty body means the message was accepted; Roblox does not guarantee delivery to every server instance
  5. Keep message payloads under the platform message size limit and serialize structured data as JSON strings within the message field

Known gotchas

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