# SDK agents

SDK agents let you use other agent SDK frameworks inside Mastra. Use them to register SDK-backed agents in a Mastra project while the provider SDK keeps its own runtime, tools, permissions, and agent loop.

## When to use SDK agents

- A vendor SDK already owns the agent loop, tools, permissions, or local runtime.
- You want to register that SDK-backed agent in a Mastra project.
- You need Mastra-compatible `generate()` and `stream()` outputs.
- You want usage, cost, and tool activity from the SDK run to appear in Mastra observability.

## Supported SDK agents

- [Claude Agent SDK](#claude-agent-sdk): Use `@mastra/claude` to register a Claude SDK agent and call it with Mastra `generate()` and `stream()`.
- [Cursor Agent SDK](#cursor-agent-sdk): Use `@mastra/cursor` to register a Cursor SDK agent and call it with Mastra `generate()` and `stream()`.

## Claude Agent SDK

Use `@mastra/claude` for Claude Code runtime configuration, permissions, tools, and agent-loop behavior.

### Install Claude packages

Install the Mastra package and the Claude Agent SDK peer dependency:

**npm**:

```bash
npm install @mastra/claude @anthropic-ai/claude-agent-sdk
```

**pnpm**:

```bash
pnpm add @mastra/claude @anthropic-ai/claude-agent-sdk
```

**Yarn**:

```bash
yarn add @mastra/claude @anthropic-ai/claude-agent-sdk
```

**Bun**:

```bash
bun add @mastra/claude @anthropic-ai/claude-agent-sdk
```

Set the Claude SDK credential:

```bash
export ANTHROPIC_API_KEY="..."
```

### Create a Claude SDK agent

Configure Claude Agent SDK through `sdkOptions`.

```typescript
import { ClaudeSDKAgent } from '@mastra/claude'

export const claudeSDKAgent = new ClaudeSDKAgent({
  id: 'claude-sdk-agent',
  name: 'Claude SDK Agent',
  description: 'Use Claude Agent SDK through Mastra.',
  sdkOptions: {
    model: 'claude-sonnet-4-6',
    cwd: process.cwd(),
  },
})
```

### Add Claude SDK tools

Claude Agent SDK tools are provided through Claude SDK Model Context Protocol (MCP) servers. Create the server with the Claude SDK, then pass it through `sdkOptions.mcpServers`.

```typescript
import { createSdkMcpServer } from '@anthropic-ai/claude-agent-sdk'
import { ClaudeSDKAgent } from '@mastra/claude'
import { getTemperature } from '../tools/get-temperature'

const weatherServer = createSdkMcpServer({
  name: 'weather',
  version: '1.0.0',
  tools: [getTemperature],
})

export const claudeSDKAgent = new ClaudeSDKAgent({
  id: 'claude-sdk-agent',
  name: 'Claude SDK Agent',
  description: 'Use Claude Agent SDK through Mastra.',
  sdkOptions: {
    model: 'claude-sonnet-4-6',
    cwd: process.cwd(),
    mcpServers: {
      weather: weatherServer,
    },
    allowedTools: ['mcp__weather__get_temperature'],
  },
})
```

The `allowedTools` value uses Claude Agent SDK MCP tool naming: `mcp__<server name>__<tool name>`.

## Cursor Agent SDK

Use `@mastra/cursor` to register a Cursor SDK agent in Mastra while keeping Cursor-specific setup in Cursor SDK options.

### Install Cursor packages

Install the Mastra package and the Cursor SDK peer dependency:

**npm**:

```bash
npm install @mastra/cursor @cursor/sdk
```

**pnpm**:

```bash
pnpm add @mastra/cursor @cursor/sdk
```

**Yarn**:

```bash
yarn add @mastra/cursor @cursor/sdk
```

**Bun**:

```bash
bun add @mastra/cursor @cursor/sdk
```

Set the Cursor SDK credential:

```bash
export CURSOR_API_KEY="..."
```

### Create a Cursor SDK agent

Configure Cursor Agent SDK through `sdkOptions`.

```typescript
import { CursorSDKAgent } from '@mastra/cursor'

export const cursorSDKAgent = new CursorSDKAgent({
  id: 'cursor-sdk-agent',
  name: 'Cursor SDK Agent',
  description: 'Use Cursor Agent SDK through Mastra.',
  sdkOptions: {
    apiKey: process.env.CURSOR_API_KEY,
    model: {
      id: 'gpt-5.5',
    },
    local: {
      cwd: process.cwd(),
    },
  },
})
```

Cursor local agents require an explicit model. Set it in `sdkOptions.model`.

### Use an existing Cursor SDK agent

If your app already creates a Cursor SDK agent, pass that agent to `CursorSDKAgent` instead:

```typescript
import { Agent as CursorAgent } from '@cursor/sdk'
import { CursorSDKAgent } from '@mastra/cursor'

const cursorAgent = CursorAgent.create({
  apiKey: process.env.CURSOR_API_KEY,
  model: {
    id: 'gpt-5.5',
  },
  local: {
    cwd: process.cwd(),
  },
})

export const cursorSDKAgent = new CursorSDKAgent({
  id: 'cursor-sdk-agent',
  name: 'Cursor SDK Agent',
  description: 'Use Cursor Agent SDK through Mastra.',
  agent: cursorAgent,
})
```

### Add Cursor SDK tools

Cursor Agent SDK tools are configured with Cursor SDK options. Pass Model Context Protocol (MCP) servers through `sdkOptions.mcpServers`:

```typescript
import { CursorSDKAgent } from '@mastra/cursor'
import { mcpServers } from '../mcp/cursor'

export const cursorSDKAgent = new CursorSDKAgent({
  id: 'cursor-sdk-agent',
  name: 'Cursor SDK Agent',
  description: 'Use Cursor Agent SDK through Mastra.',
  sdkOptions: {
    apiKey: process.env.CURSOR_API_KEY,
    model: {
      id: 'gpt-5.5',
    },
    local: {
      cwd: process.cwd(),
    },
    mcpServers,
  },
})
```

## Register SDK agents

Register SDK agents in the Mastra instance like other agents:

```typescript
import { Mastra } from '@mastra/core'
import { claudeSDKAgent } from './agents/claude-sdk-agent'
import { cursorSDKAgent } from './agents/cursor-sdk-agent'

export const mastra = new Mastra({
  agents: {
    claudeSDKAgent,
    cursorSDKAgent,
  },
})
```

After registration, call them with `mastra.getAgentById()`:

```typescript
import { mastra } from './index'

const agent = mastra.getAgentById('cursor-sdk-agent')
const stream = await agent.stream('Inspect this project and describe the test setup.')

for await (const chunk of stream.textStream) {
  process.stdout.write(chunk)
}
```

## Observability

SDK agents create Mastra agent and model spans for `generate()` and `stream()` calls. Mastra records SDK-provided usage, tool activity, and provider metadata when the vendor SDK exposes those events.

Claude SDK runs can include SDK-estimated cost from the Claude result message. Cursor SDK runs include token usage from Cursor interaction updates.

For storage and dashboard setup, see [Observability](https://mastra.ai/docs/observability/overview).

## Related

- [Agents overview](https://mastra.ai/docs/agents/overview)
- [Tools](https://mastra.ai/docs/agents/using-tools)
- [Observability](https://mastra.ai/docs/observability/overview)