{"source":"semconv","version":"1.44.0","attribute":{"id":"messaging.kafka.message.key","type":"string","stability":"development","brief":"Message keys in Kafka are used for grouping alike messages to ensure they're processed on the same partition. They differ from `messaging.message.id` in that they're not unique. If the key is `null`, the attribute MUST NOT be set.","note":"If the key type is not string, it's string representation has to be supplied for the attribute. If the key has no unambiguous, canonical string form, don't include its value.","examples":["myKey"],"namespace":"messaging","definedIn":"model/messaging/registry.yaml","usedBy":[{"groupId":"messaging.kafka.attributes.common","groupType":"attribute_group","requirementLevel":"recommended"},{"groupId":"span.messaging.kafka.create.producer","groupType":"span","signalName":"messaging.create.producer","requirementLevel":"recommended"},{"groupId":"span.messaging.kafka.process.consumer","groupType":"span","signalName":"messaging.process.consumer","requirementLevel":"recommended"},{"groupId":"span.messaging.kafka.receive.client","groupType":"span","signalName":"messaging.receive.client","requirementLevel":"recommended"},{"groupId":"span.messaging.kafka.send.client","groupType":"span","signalName":"messaging.send.client","requirementLevel":"recommended"},{"groupId":"span.messaging.kafka.send.producer","groupType":"span","signalName":"messaging.send.producer","requirementLevel":"recommended"}]},"history":[{"version":"1.30.0","publishedAt":"2025-01-24T19:11:42Z","kind":"first-seen","detail":"Already present at v1.30.0, the oldest release tracked here (experimental)."},{"version":"1.31.0","publishedAt":"2025-03-11T00:53:13Z","kind":"stability-changed","detail":"Stability label respelled from experimental to development.","severity":"informational"}],"replaces":[]}