title: Kafka
tagline: Single-node Kafka-protocol broker, no JVM.
category: queue
engine: kafka
port: 9092
example: |-
    kafka "events" {
      version = 4
      port    = 9092

      auto_create_topics = true
      default_partitions = 1
      retention          = "168h"

      topic "orders" {
        partitions = 3
      }
      topic "payments" {
        partitions = 1
        config = { "cleanup.policy" = "compact" }
      }
    }
exampleLabel: events
description: A local, disk-backed broker that speaks enough of the Kafka wire protocol that unmodified clients (franz-go, kcat, Sarama, the Java client) connect and work. No JVM, no ZooKeeper, no KRaft — the engine is doze-kafka, embedded in the module, and `version` selects the Kafka protocol profile it advertises (1–4). Declare topics and doze converges them on boot; auto-create handles the rest.
homepage: https://github.com/doze-dev/doze-modules/tree/main/modules/kafka
source: doze/kafka
config:
    arguments:
        - name: version
          type: number
          desc: Advertised Kafka protocol profile — 1, 2, 3, or 4.
          required: true
        - name: auto_create_topics
          type: bool
          default: "true"
          desc: Create unknown topics on first reference.
        - name: default_partitions
          type: number
          default: "1"
          desc: Partition count for auto-created topics.
        - name: retention
          type: string
          desc: Delete segments older than this (Go duration, e.g. "168h"); empty = unbounded.
        - name: retention_bytes
          type: number
          desc: Delete old segments once a partition exceeds this size (0 = unbounded).
    blocks:
        - name: topic
          label: name
          desc: A topic to create on boot.
          arguments:
            - name: partitions
              type: number
              default: "1"
              desc: Partition count.
            - name: config
              type: map(string)
              desc: Per-topic config (e.g. cleanup.policy = compact).