> For the complete documentation index, see [llms.txt](https://docs.coherent.global/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coherent.global/hybrid-runner/how-to-set-up-the-hybrid-runner/manage-compatible-neuron-versions.md).

# Manage compatible Neuron versions

{% hint style="danger" %}
This will no longer be updated after `nodegen-server` `1.56.1`.
{% endhint %}

{% hint style="info" %}
The compatibility feature in the runner is included in `nodegen-server` `>=1.3.0`.

[Neuron](/build-spark-services/neuron.md) compiler versions `>=1.22.1` embed the compiler version into the ZIP package. If this feature is enabled and compiler version cannot be found, the runner assume the [Neuron](/build-spark-services/neuron.md) version will be compatible.
{% endhint %}

The list of [Neuron](/build-spark-services/neuron.md) compatibility versions that can be found in the repository [`nodegen-server-compatibility`](https://github.com/Coherent-Partners/nodegen-server-compatibility).

`nodegen-server` also has the ability to check whether [Neuron](/build-spark-services/neuron.md) Wasms are supported by the version of the runner you are using. This is done by downloading the JSON file from [`nodegen-server-compatibility`](https://github.com/Coherent-Partners/nodegen-server-compatibility) and assessing it against the versions of the runner and the requested Wasm. This can only be done with an online connection to fetch the necessary compatibility files.

This can be configured through the use of these additional [`docker image run`](https://docs.docker.com/engine/reference/commandline/run/) environment variables.

| Environment variable                          | Value                                                                                                                                                                                                                                                                     |
| --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `NODEGEN_COMPATIBILITY_BASE_URL`              | <p>Base URL for Github user content.<br><br><code><https://raw.githubusercontent.com></code></p>                                                                                                                                                                          |
| `NODEGEN_COMPATIBILITY_PATH`                  | <p>Path to the JSON document in <a href="https://github.com/Coherent-Partners/nodegen-server-compatibility"><code>nodegen-server-compatibility</code></a>.<br><br><code>/Coherent-Partners/nodegen-server-compatibility/main/nodegen-server-compatibility.json</code></p> |
| `CHECK_RUNNER_COMPATIBILITY`                  | <p><code>true</code> or <code>false</code></p><p>Whether to check if the version of the runner supports this version of <a data-mention href="/build-spark-services/neuron.md">/pages/qc2ynJ5gnthNAqVrFQRg</a>. The default value is <code>false</code>.</p>              |
| `EXECUTE_WITH_WARNING`                        | <p><code>true</code> or <code>false</code></p><p><br>If <code>CHECK\_RUNNER\_COMPATIBILITY</code> is <code>true</code>, this defines whether or not to continue with executing the Spark service but with a warning. The default value is <code>false</code>.</p>         |
| `NODEGEN_COMPATIBILITY_LIST_REFRESH_INTERVAL` | If `CHECK_RUNNER_COMPATIBILITY` is `true`, this defines how often in minutes to fetch the [`nodegen-server-compatibility`](https://github.com/Coherent-Partners/nodegen-server-compatibility) JSON document. The default value is `1440`.                                 |