> For the complete documentation index, see [llms.txt](https://docs.lenses.io/latest/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lenses.io/latest/k2k/deployment/releases-and-compatibility.md).

# Releases and compatibility

K2K version matrix, supported platforms, and upgrade guidance.

## Current versions

| Component     | Version | Image / chart         |
| ------------- | ------- | --------------------- |
| K2K container | 2.1.0   | `lensesio/k2k:2.1.0`  |
| Helm chart    | 2.1.0   | `lensesio/lenses-k2k` |

Pin the container image tag and Helm chart version together. The chart version should match the application version you intend to run. When installing from the Helm repository, always pass `--version`:

```bash
helm install lenses-k2k lensesio/lenses-k2k \
  --values values.yaml \
  --create-namespace --namespace lenses-k2k \
  --version 2.1.0
```

See [Helm](/latest/k2k/deployment/helm.md) for full install instructions and [Docker](/latest/k2k/deployment/docker.md) for container deployment.

## Kafka compatibility

K2K connects to any Kafka API compatible cluster. It uses standard Kafka clients (consumer, producer, admin) and does not require clusters to run the same vendor or version.

| Capability            | Requirement                                                                               |
| --------------------- | ----------------------------------------------------------------------------------------- |
| Basic replication     | Kafka 2.x or later (or compatible managed offering)                                       |
| Exactly once delivery | Target cluster must support idempotent producers and transactions                         |
| Offset mapping        | Admin API access to list consumer groups and read committed offsets on the source cluster |
| Topic auto-creation   | Admin API access on the target cluster                                                    |

Test connectivity with [Startup validation](/latest/k2k/configuration-reference/startup-validation.md) before enabling advanced features.

## Schema Registry compatibility

K2K supports Confluent-compatible Schema Registry endpoints for [schema migration](/latest/k2k/configuration-reference/schema-migration.md). Source and target registries can run different versions as long as both expose a compatible REST API.

## Upgrade path

1. Review release notes for the target version (GitHub: [k2k-helm-charts](https://github.com/lensesio/k2k-helm-charts)).
2. Validate the updated pipeline with `k2k dry-run` — see [Deployment](/latest/k2k/deployment.md).
3. Upgrade the replicator first, then the offset mapper if deployed.
4. For Helm deployments, update `--version` and apply the chart. Rolling updates are supported for horizontally scaled deployments — see [Horizontal scaling](/latest/k2k/configuration-reference/horizontal-scaling.md).

{% hint style="warning" %}
Do not downgrade K2K while control topics contain state written by a newer version. If a rollback is required, restore from a backup or recreate control topics after stopping all K2K instances.
{% endhint %}

## Versioned documentation

Release branches in the documentation repository (for example `release/2.1.0`) may correspond to product versions. Check your GitBook space for a version switcher if you need docs for an older release.


---

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