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

# OpenCode Harness

> Pin the OpenCode SDK harness and a supported model.

Use `agent_harness="opencode_sdk"` when you want Managed Research to run through the OpenCode SDK harness.

## Launch

```python theme={null}
run = client.research.runs.start(
    "Review the repo and propose the smallest high-impact fix.",
    host_kind="daytona",
    work_mode="directed_effort",
    providers=[{"provider": "openrouter"}],
    runbook="lite",
    agent_harness="opencode_sdk",
    agent_model="anthropic/claude-haiku-4-5-20251001",
)
```

## OpenCode models

| Model ID                              | Launch access |
| ------------------------------------- | ------------- |
| `anthropic/claude-sonnet-4-6`         | Beta Access   |
| `anthropic/claude-haiku-4-5-20251001` | Standard      |
| `x-ai/grok-4.1-fast`                  | Standard      |
| `moonshotai/kimi-k2.6`                | Standard      |

OpenCode models do not list `reasoning_effort` support in the backend catalog.

## Failure notes

If the requested harness/model pair is unsupported, launch preflight and run start fail with a structured denial. See [Models and Harnesses](/managed-research/models-and-harnesses).