---
title: "Kafka - How to enable the REST API"
description: "Find out how to enable the REST API of your Kafka service and produce and consume messages over HTTPS"
url: https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-enable-rest-api
lang: en
lastUpdated: 2026-10-19
---
> For AI agents: the complete documentation index is available at https://docs.ovhcloud.com/de/llms.txt, the full documentation bundle is available at https://docs.ovhcloud.com/de/llms-full.txt.

# Kafka - How to enable the REST API

## Objective

Apache Kafka is an open-source, distributed event streaming platform designed for real-time, large-scale data processing with high scalability, durability, and low latency.

The Kafka REST API lets applications produce and consume messages over HTTPS, without a Kafka client library.

This guide explains how to enable the REST API of your Kafka service with the OVHcloud API, then how to produce and consume a first message with `curl`.

## Requirements

- A [Public Cloud project](https://www.ovhcloud.com/de/public-cloud/) in your OVHcloud account
- A [Kafka service](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-create-cluster.md) [accepting incoming connections](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-incoming-connections.md) from your IP address
- A topic, and a user with the `readwrite` permission on it (see the [ACL guide](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-configure-acl.md))
- Access to the [OVHcloud API](https://docs.ovhcloud.com/de/guides/manage-and-operate/api/first-steps.md)

## Instructions

### Enabling the REST API

Update your service with `restApi` set to `true` (or `false` to disable the REST API):

[PUT /cloud/project/{serviceName}/database/kafka/{clusterId}](https://api.eu.ovhcloud.com/console/?section=/cloud&branch=v1#put-/cloud/project/-serviceName-/database/kafka/-clusterId-)

```json
{
  "restApi": true
}
```

### Retrieving the REST API endpoint

Once the REST API is enabled, a `kafkaRestApi` endpoint is added to your service. You can find it in the `endpoints` list of the service details:

[GET /cloud/project/{serviceName}/database/kafka/{clusterId}](https://api.eu.ovhcloud.com/console/?section=/cloud&branch=v1#get-/cloud/project/-serviceName-/database/kafka/-clusterId-)

```json
{
  "component": "kafkaRestApi",
  "domain": "kafka-xxxxxxxx-xxxxxxxxx.database.cloud.ovh.net",
  "port": 20188,
  "scheme": "https",
  "ssl": true,
  "uri": "https://<username>:<password>@kafka-xxxxxxxx-xxxxxxxxx.database.cloud.ovh.net:20188"
}
```

The REST API uses HTTPS with the CA certificate of your service, and the username and password of a Kafka user. Download the CA certificate as `ca.pem` (see [Connect to a Kafka cluster with CLI](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-connect-cluster-cli.md)).

**Note:** A user you have just created can be rejected with `401 Unauthorized` for about a minute, until it is available on the REST API.

### Listing topics

```bash
curl --cacert ca.pem -u 'app-orders:<password>' https://<host>:<port>/topics
```

```json
["orders","__consumer_offsets"]
```

### Producing a message

Send a JSON message with the key `order-1` to the `orders` topic:

```bash
curl --cacert ca.pem -u 'app-orders:<password>' \
  -H 'Content-Type: application/vnd.kafka.json.v2+json' \
  -X POST https://<host>:<port>/topics/orders \
  -d '{"records":[{"key":"order-1","value":{"amount":42}}]}'
```

The REST API returns the partition and offset of the message:

```json
{"key_schema_id":null,"offsets":[{"offset":0,"partition":0}],"value_schema_id":null}
```

### Consuming messages

Consuming takes three steps: create a consumer instance in a consumer group, subscribe it to the topic, then read the records.

```bash

# 1. Create the consumer instance "c1" in the consumer group "orders-readers"

curl --cacert ca.pem -u 'app-orders:<password>' \
  -H 'Content-Type: application/vnd.kafka.v2+json' \
  -X POST https://<host>:<port>/consumers/orders-readers \
  -d '{"name":"c1","format":"json","auto.offset.reset":"earliest"}'

# 2. Subscribe it to the "orders" topic

curl --cacert ca.pem -u 'app-orders:<password>' \
  -H 'Content-Type: application/vnd.kafka.v2+json' \
  -X POST https://<host>:<port>/consumers/orders-readers/instances/c1/subscription \
  -d '{"topics":["orders"]}'

# 3. Read the records

curl --cacert ca.pem -u 'app-orders:<password>' \
  -H 'Accept: application/vnd.kafka.json.v2+json' \
  https://<host>:<port>/consumers/orders-readers/instances/c1/records
```

The REST API returns the messages of the topic:

```json
[{"key":"order-1","offset":0,"partition":0,"timestamp":1791971865910,"topic":"orders","value":{"amount":42}}]
```

When you are done, delete the consumer instance:

```bash
curl --cacert ca.pem -u 'app-orders:<password>' \
  -H 'Content-Type: application/vnd.kafka.v2+json' \
  -X DELETE https://<host>:<port>/consumers/orders-readers/instances/c1
```

## Go further

[Kafka - How to use Access Control Lists (ACLs)](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-configure-acl.md)

[Kafka - How to enable the Schema Registry](https://docs.ovhcloud.com/de/guides/public-cloud/data-analytics/analytics/kafka-enable-schema-registry.md)

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