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

# Harness

> Choose how an agent runs each turn.

A harness controls the agent loop that processes messages, calls tools, and
returns results. Funky currently supports two harnesses:

| Harness          | Runtime type  | Notes                                                                   |
| ---------------- | ------------- | ----------------------------------------------------------------------- |
| **Funky native** | `native`      | Funky's built-in, provider-neutral agent loop                           |
| **Claude Code**  | `claude-code` | Runs turns through the Claude Agent SDK and requires an Anthropic model |

The Funky native harness is used when `runtime` is omitted. You can also select
it explicitly:

```json theme={null}
{
  "runtime": {
    "type": "native"
  }
}
```

To use Claude Code, configure an Anthropic model and set the runtime type:

```json theme={null}
{
  "model": {
    "provider": "anthropic",
    "model": "claude-sonnet-5"
  },
  "runtime": {
    "type": "claude-code"
  }
}
```

<Note>
  Pi, Codex, and Antigravity harnesses are coming soon.
</Note>