> ## Documentation Index
> Fetch the complete documentation index at: https://goldrush.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Kafka

> Configure a Kafka destination for the GoldRush Pipeline API to forward raw blockchain data with exactly-once delivery.

The Kafka destination forwards raw bytes from the pipeline source directly to a target Kafka topic. Unlike other destinations, Kafka operates in **Raw** pipeline mode - no normalization, ABI decoding, or transforms are applied.

## Configuration

```yaml theme={null}
destination:
  type: "kafka"
  bootstrap_servers: "broker1:9092,broker2:9092"
  sasl:
    mechanism: "SCRAM-SHA-512"
    username: "${KAFKA_USER}"
    password: "${KAFKA_PASSWORD}"
  output_topic: "my-output-topic"
```

### Fields

| Field               | Type   | Required | Description                            |
| ------------------- | ------ | -------- | -------------------------------------- |
| `bootstrap_servers` | string | yes      | Target Kafka broker addresses          |
| `sasl.mechanism`    | string | yes      | SASL mechanism (e.g., `SCRAM-SHA-512`) |
| `sasl.username`     | string | yes      | SASL username                          |
| `sasl.password`     | string | yes      | SASL password                          |
| `output_topic`      | string | yes      | Target topic name                      |

## Key Behavior

* **Raw passthrough** - bytes from the source are forwarded without any processing. No normalization, ABI decoding, or transform stages run.
* **Exactly-once delivery** - the destination uses transactional producing to guarantee exactly-once semantics end to end.
* **Validation at startup** - if your pipeline configuration includes `abi` or `transforms` sections alongside a Kafka destination, the pipeline will reject the configuration and fail to start.

<Warning>
  ABI decoding and transform configurations are not compatible with the Kafka destination. Remove those sections from your pipeline definition before deploying.
</Warning>