> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/nemoclaw/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/nemoclaw/_mcp/server.

# Choose a Compatible Inference API

> Choose the Chat Completions or Responses API for a custom OpenAI-compatible endpoint.

Custom OpenAI-compatible endpoints use `/v1/chat/completions` at runtime by default.
Choose the Responses API only when your endpoint implements the required streaming and tool-calling behavior.

## Understand the Default Probe

During onboarding, NemoClaw probes `/v1/responses` first with tool-calling and streaming checks.
It falls back to `/v1/chat/completions` when the Responses API does not provide the required behavior.

A successful Responses probe does not change the runtime API by itself.
Without an explicit preference, the sandbox still uses `/v1/chat/completions`.
This default avoids local backends that accept Responses requests but drop system prompts or tool definitions.

When a reasoning model returns only reasoning content before a final answer, NemoClaw retries the smoke request with a larger response budget.
Route, configuration, and authentication failures still fail immediately.

## Select the Responses API

Set `NEMOCLAW_PREFERRED_API=openai-responses` before onboarding.

```bash
NEMOCLAW_PREFERRED_API=openai-responses nemohermes onboard
```

NemoClaw selects `/v1/responses` only when the validation response includes the required streaming events.
If that probe fails, onboarding falls back to `/v1/chat/completions` automatically.

## Select Chat Completions Only

Set `NEMOCLAW_PREFERRED_API=openai-completions` to skip the Responses probe and validate only `/v1/chat/completions`.
This setting works in interactive and non-interactive onboarding.

```bash
NEMOCLAW_PREFERRED_API=openai-completions nemohermes onboard
```

| Variable                 | Values                                   | Default                                        |
| ------------------------ | ---------------------------------------- | ---------------------------------------------- |
| `NEMOCLAW_PREFERRED_API` | `openai-completions`, `openai-responses` | Unset, which uses Chat Completions at runtime. |

## Reconfigure an Existing Sandbox

Rerun onboarding after changing the preferred API.
NemoClaw probes the endpoint again and writes the selected API path into the rebuilt sandbox image.

```bash
nemohermes onboard
```

`NEMOCLAW_INFERENCE_API_OVERRIDE` changes the container-startup configuration but does not update the API path baked into the sandbox image.
If you later recreate the sandbox without the override, the image returns to its original API path.
Rerun onboarding to persist the API choice in both the session and image.

## Related Topics

* [Set Up an OpenAI-Compatible Endpoint](set-up-openai-compatible-endpoint) for endpoint configuration.
* [Understand Provider Validation](../validate-inference/understand-provider-validation) for validation behavior across providers.