---
summary: "DeepSeek setup (auth + model selection)"
title: "DeepSeek"
read_when:
  - You want to use DeepSeek with Nodmix
  - You need the API key env var or CLI auth choice
---

[DeepSeek](https://www.deepseek.com) provides powerful AI models with an OpenAI-compatible API.

| Property | Value                      |
| -------- | -------------------------- |
| Provider | `deepseek`                 |
| Auth     | `DEEPSEEK_API_KEY`         |
| API      | OpenAI-compatible          |
| Base URL | `https://api.deepseek.com` |

## Getting started

<Steps>
  <Step title="Get your API key">
    Create an API key at [platform.deepseek.com](https://platform.deepseek.com/api_keys).
  </Step>
  <Step title="Run onboarding">
    ```bash
    nodmix onboard --auth-choice deepseek-api-key
    ```

    This will prompt for your API key and set `deepseek/deepseek-v4-flash` as the default model.

  </Step>
  <Step title="Verify models are available">
    ```bash
    nodmix models list --provider deepseek
    ```

    To inspect the bundled static catalog without requiring a running Gateway,
    use:

    ```bash
    nodmix models list --all --provider deepseek
    ```

  </Step>
</Steps>

<AccordionGroup>
  <Accordion title="Non-interactive setup">
    For scripted or headless installations, pass all flags directly:

    ```bash
    nodmix onboard --non-interactive \
      --mode local \
      --auth-choice deepseek-api-key \
      --deepseek-api-key "$DEEPSEEK_API_KEY" \
      --skip-health \
      --accept-risk
    ```

  </Accordion>
</AccordionGroup>

<Warning>
If the Gateway runs as a daemon (launchd/systemd), make sure `DEEPSEEK_API_KEY`
is available to that process (for example, in `~/.nodmix/.env` or via
`env.shellEnv`).
</Warning>

## Built-in catalog

| Model ref                    | Name              | Input | Context   | Max output | Notes                                      |
| ---------------------------- | ----------------- | ----- | --------- | ---------- | ------------------------------------------ |
| `deepseek/deepseek-v4-flash` | DeepSeek V4 Flash | text  | 1,000,000 | 384,000    | Default model; V4 thinking-capable surface |
| `deepseek/deepseek-v4-pro`   | DeepSeek V4 Pro   | text  | 1,000,000 | 384,000    | V4 thinking-capable surface                |
| `deepseek/deepseek-chat`     | DeepSeek Chat     | text  | 131,072   | 8,192      | DeepSeek V3.2 non-thinking surface         |
| `deepseek/deepseek-reasoner` | DeepSeek Reasoner | text  | 131,072   | 65,536     | Reasoning-enabled V3.2 surface             |

<Tip>
V4 models support DeepSeek's `thinking` control. Nodmix also replays
DeepSeek `reasoning_content` on follow-up turns so thinking sessions with tool
calls can continue.
Use `/think xhigh` or `/think max` with DeepSeek V4 models to request DeepSeek's
maximum `reasoning_effort`.
</Tip>

## Thinking and tools

DeepSeek V4 thinking sessions have a stricter replay contract than most
OpenAI-compatible providers: after a thinking-enabled turn uses tools, DeepSeek
expects replayed assistant messages from that turn to include
`reasoning_content` on follow-up requests. Nodmix handles this inside the
DeepSeek plugin, so normal multi-turn tool use works with
`deepseek/deepseek-v4-flash` and `deepseek/deepseek-v4-pro`.

If you switch an existing session from another OpenAI-compatible provider to a
DeepSeek V4 model, older assistant tool-call turns may not have native
DeepSeek `reasoning_content`. Nodmix fills that missing field on replayed
assistant messages for DeepSeek V4 thinking requests so the provider can accept
the history without requiring `/new`.

When thinking is disabled in Nodmix (including the UI **None** selection),
Nodmix sends DeepSeek `thinking: { type: "disabled" }` and strips replayed
`reasoning_content` from the outgoing history. This keeps disabled-thinking
sessions on the non-thinking DeepSeek path.

Use `deepseek/deepseek-v4-flash` for the default fast path. Use
`deepseek/deepseek-v4-pro` when you want the stronger V4 model and can accept
higher cost or latency.

## Live testing

The direct live model suite includes DeepSeek V4 in the modern model set. To
run only the DeepSeek V4 direct-model checks:

```bash
NODMIX_LIVE_PROVIDERS=deepseek \
NODMIX_LIVE_MODELS="deepseek/deepseek-v4-flash,deepseek/deepseek-v4-pro" \
pnpm test:live src/agents/models.profiles.live.test.ts
```

That live check verifies both V4 models can complete and that thinking/tool
follow-up turns preserve the replay payload DeepSeek requires.

## Config example

```json5
{
  env: { DEEPSEEK_API_KEY: "sk-..." },
  agents: {
    defaults: {
      model: { primary: "deepseek/deepseek-v4-flash" },
    },
  },
}
```

## Related

<CardGroup cols={2}>
  <Card title="Model selection" href="/concepts/model-providers" icon="layers">
    Choosing providers, model refs, and failover behavior.
  </Card>
  <Card title="Configuration reference" href="/gateway/configuration-reference" icon="gear">
    Full config reference for agents, models, and providers.
  </Card>
</CardGroup>
