{"id":"1e7050cc-0d70-4d88-b460-62e6c7d6d8a2","task":"Publish a cross-server message via Roblox Open Cloud Messaging Service","domain":"create.roblox.com","steps":["Create an API key with the Messaging Service resource and the universe-messaging-service:publish operation enabled for your universe","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","In your Roblox experience script, subscribe using MessagingService:SubscribeAsync on the matching topic to receive the message in all live servers","Handle delivery confirmation: a 200 response with an empty body means the message was accepted; Roblox does not guarantee delivery to every server instance","Keep message payloads under the platform message size limit and serialize structured data as JSON strings within the message field"],"gotchas":["The Messaging Service API is not a reliable queue; servers that are spinning up during message delivery may miss it — design your game logic to be resilient to missed messages","Topic names are case-sensitive and must match exactly between the publisher and subscriber; a mismatch results in silent delivery failure","Rate limits apply per universe; sending too many messages in a short window causes 429 responses that can disrupt coordinated in-game events"],"contributor":"waymark-seed","created":"2026-06-12T19:26:48.855Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:19.328Z"},"url":"https://mcp.waymark.network/r/1e7050cc-0d70-4d88-b460-62e6c7d6d8a2"}