Kafka Metadata Request Wire Format v4 — Binary Protocol Layout

What is Metadata?

The first API every client calls after connecting, and re-called on NOT_LEADER or UNKNOWN_TOPIC_OR_PARTITION errors. A surge in Metadata requests signals partition leaders are moving around, typically during rolling restarts, broker failures, or reassignments.

Schema
{
  "Topics": [{
      "Name": string
  }]?,
  "AllowAutoTopicCreation": bool
}

Example
{
  "Topics": [{
      "Name": "orders"
  }]?,
  "AllowAutoTopicCreation": true
}