Karapace
Karapace is an open-source Schema Registry and REST Proxy built by Aiven for Aiven for Apache Kafka.
What Karapace is
Karapace is an open-source Schema Registry and REST Proxy built by Aiven for Aiven for Apache Kafka. The registry stores and versions schemas, and can check compatibility before a change is published. It handles Avro, Protobuf, and JSON Schema; references are supported for Avro and Protobuf. Its REST Proxy provides HTTP APIs for producing and consuming Kafka events, so scripts and HTTP-based services can work with events. Both components support OAuth 2.0/OIDC authentication. Registry access can use ACLs, while OIDC role-based authorization can restrict operations by HTTP method. The project documents Docker setup and installation from source with pip, and states API-level compatibility with Schema Registry 6.1.1. Karapace is included in Aiven's Kafka free tier, described for learning, prototyping, and evaluation. The Free plan is free, with throughput up to 250 KiB/s, retention up to three days, and up to five topics with two partitions each. The Developer plan is $35 a month. Built-in schema backup was removed in version 6.0.0 and is no longer maintained.
Good
- Stores and versions Avro, Protobuf, and JSON Schema.
- Checks schema compatibility before publication.
- REST Proxy supports HTTP event production and consumption.
- Supports OAuth 2.0/OIDC authentication.
- Free plan includes Schema Registry and REST Proxy.
Watch out
- Free plan throughput is capped at 250 KiB/s.
- Free plan retention is up to three days.
- Built-in schema backup was removed in version 6.0.0.
Who it suits
Karapace suits teams using Aiven for Apache Kafka that need schema management or HTTP-based event access. Its documented Docker and source installation options may also suit self-hosted deployments.
Verdict
Karapace brings schema management and an HTTP proxy to Kafka workflows, with authentication and authorization controls. Note the free tier's listed limits and the absence of maintained built-in schema backup.
Plans and prices
From Karapace's own pricing page, checked 2 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Up to 250 KiB/s throughput · retention up to 3 days · up to 5 topics, each with two partitions · Schema Registry and REST proxy included · $0/month |
| Developer | $35 a month | Up to 1 MB/s throughput · retention up to 3 days · up to 20 topics (max 100 partitions) · Schema Registry and REST proxy included · $35/month; $0.04/hour |
The facts
Each one read from Karapace's own pages, with the date it was checked.
What it does
- Authentication
- Karapace supports OAuth 2.0/OIDC authentication for Schema Registry and the REST Proxy.checked 2 Oct 2026
- Authorization
- Schema Registry authorization uses access control lists, and OIDC role-based authorization can restrict operations by HTTP method.checked 2 Oct 2026
- Compatibility
- The project states that Karapace is compatible with Schema Registry 6.1.1 at the API level and supports all operations in that API.checked 2 Oct 2026
- Deployment
- The project documents Docker-based setup and installation from source with pip.checked 2 Oct 2026
- HTTP access
- The REST Proxy exposes APIs for producing and consuming Kafka events over HTTP, including use from scripts, curl, and HTTP-based services.checked 2 Oct 2026
- Identity providers
- The OAuth/OIDC setup documentation lists Auth0, Okta, Google Identity Platform, and Azure as example compliant providers.checked 2 Oct 2026
- Integrations
- The Aiven Terraform Provider supports managing Karapace Schema Registry authorization ACL entries.checked 2 Oct 2026
- Notable limit
- Karapace’s built-in schema backup functionality was removed in version 6.0.0 and is no longer maintained in the project.checked 2 Oct 2026
- Schema management
- The Schema Registry stores and versions schemas and can check compatibility before changes are published.checked 2 Oct 2026
- Supported formats
- Karapace supports Avro, Protobuf, and JSON Schema registration; schema references are supported for Avro and Protobuf.checked 2 Oct 2026
- What it does
- Karapace is an Aiven-built open-source Schema Registry and REST Proxy for Aiven for Apache Kafka.checked 2 Oct 2026
The company
- Company headquarters
- Aiven says it is headquartered in Helsinki, Finland.checked 2 Oct 2026
- Founded
- 2016checked 28 Sep 2026
- Headquarters
- Helsinki, Finlandchecked 28 Sep 2026
Money
- Free tier scope
- Aiven’s Kafka free tier includes Karapace Schema Registry and is described as intended for learning, prototyping, and evaluation.checked 2 Oct 2026
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