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

# Compatibility

> Check the platform and installed client contract.

Kast currently admits macOS on Apple silicon, an on-disk Kotlin Gradle
repository, IntelliJ IDEA `262.*`, its bundled Kotlin plugin, and its
Java 25 JBR. The installer rejects an IDEA release line without a matching
Kast plugin.

| Client           | Contract to inspect after installation or upgrade |
| ---------------- | ------------------------------------------------- |
| MCP              | Live `tools/list` result                          |
| Tool RPC         | Live `catalog` reply                              |
| Codex App Server | Provider catalog for the conversation             |

Tool schemas and exact `ref` values are bound to their installed runtime
and admitted workspace. Rediscover tools after an upgrade; search again
when a reference is stale.

The Codex App Server integration remains a preview. See the
[source-backed compatibility record](https://github.com/amichne/kast/blob/main/app-server/docs/compatibility.md)
for its tested client boundary.