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

# DeepSeek

> Use DeepSeek reasoning and chat models with Agentium agents.

# DeepSeek

Use DeepSeek's powerful language models — including the `deepseek-reasoner` for complex multi-step reasoning and `deepseek-chat` for general conversations.

DeepSeek exposes an **OpenAI-compatible API**, so Agentium connects using the standard `openai` SDK pointed at `https://api.deepseek.com`.

<Info>
  DeepSeek has no rate limits. During high-traffic periods, responses may be slower rather than rejected. See [DeepSeek docs](https://api-docs.deepseek.com/quick_start/rate_limit).
</Info>

***

## Setup

<Tabs>
  <Tab title="Install">
    ```bash theme={null}
    npm install openai
    ```
  </Tab>

  <Tab title="Environment">
    Get your API key from [platform.deepseek.com](https://platform.deepseek.com/api_keys):

    ```bash theme={null}
    export DEEPSEEK_API_KEY="..."
    ```
  </Tab>
</Tabs>

***

## Factory

```typescript theme={null}
import { deepseek } from "@agentium/core";

const model = deepseek("deepseek-chat");
```

<ParamField path="modelId" type="string" required>
  Model ID (e.g., `"deepseek-chat"`, `"deepseek-reasoner"`).
</ParamField>

<ParamField path="config" type="DeepSeekConfig" required={false}>
  Optional `{ apiKey?, baseURL? }`.
</ParamField>

***

## Supported Models

| Model               | Description                              | Best For                                 |
| ------------------- | ---------------------------------------- | ---------------------------------------- |
| `deepseek-chat`     | General-purpose conversational model     | Most tasks, fast responses               |
| `deepseek-reasoner` | Advanced reasoning with chain-of-thought | Complex math, logic, multi-step problems |

***

## Basic Example

```typescript theme={null}
import { Agent, deepseek } from "@agentium/core";

const agent = new Agent({
  name: "deepseek-agent",
  model: deepseek("deepseek-chat"),
  instructions: "You are a helpful assistant.",
});

const result = await agent.run("Explain quantum entanglement in simple terms.");
console.log(result.text);
```

***

## Reasoning Model

The `deepseek-reasoner` model returns chain-of-thought reasoning via `reasoning_content`:

```typescript theme={null}
import { Agent, deepseek } from "@agentium/core";

const agent = new Agent({
  name: "math-solver",
  model: deepseek("deepseek-reasoner"),
  instructions: "Solve problems step by step.",
});

const result = await agent.run(
  "A train leaves Station A at 60 mph. Another leaves Station B (300 miles away) at 80 mph toward A. When do they meet?"
);
console.log(result.text);
```

***

## Tool Calling

```typescript theme={null}
import { Agent, deepseek, defineTool } from "@agentium/core";
import { z } from "zod";

const agent = new Agent({
  name: "tool-agent",
  model: deepseek("deepseek-chat"),
  tools: [
    defineTool({
      name: "getWeather",
      description: "Get current weather for a city",
      parameters: z.object({ city: z.string() }),
      execute: async ({ city }) => `${city}: 18°C, Clear skies`,
    }),
  ],
});

const result = await agent.run("What's the weather in Tokyo?");
console.log(result.text);
```

***

## Full Example

```typescript theme={null}
import { Agent, deepseek, CostTracker, defineTool } from "@agentium/core";
import { z } from "zod";

const costTracker = new CostTracker({
  pricing: {
    "deepseek-chat": { promptPer1k: 0.00014, completionPer1k: 0.00028 },
    "deepseek-reasoner": { promptPer1k: 0.00055, completionPer1k: 0.00219 },
  },
});

const agent = new Agent({
  name: "research-assistant",
  model: deepseek("deepseek-chat"),
  instructions: "You are a research assistant. Be thorough and cite sources.",
  tools: [
    defineTool({
      name: "search",
      description: "Search the web",
      parameters: z.object({ query: z.string() }),
      execute: async ({ query }) => `Results for "${query}": ...`,
    }),
  ],
  costTracker,
  maxToolRoundtrips: 5,
});

const result = await agent.run("What are the latest advances in fusion energy?");
console.log(result.text);
console.log(`Cost: $${costTracker.getSummary().totalCost.toFixed(6)}`);
```

***

## Environment Variables

| Variable           | Description      |
| ------------------ | ---------------- |
| `DEEPSEEK_API_KEY` | DeepSeek API key |

***

## Cross-References

* [OpenAI](/models/openai) — Similar API format, different models
* [Ollama](/models/ollama) — Run DeepSeek models locally via Ollama
* [Reasoning](/agents/reasoning) — Reasoning configuration guide