Build Your First Programmatic Coding Agent with the Cursor TypeScript SDK

Cursor has been the AI coding IDE story for the past year. Now, with the launch of the @cursor/sdk TypeScript package in public beta, it’s also becoming a platform you can build on top of.

This guide walks through what the Cursor TypeScript SDK enables, how to get started, and how to structure your first programmatic coding agent.

What the Cursor TypeScript SDK Does

The @cursor/sdk gives developers a TypeScript API for creating and controlling coding agents programmatically — the same agents that power Cursor’s internal composer, but accessible outside the IDE and embeddable in your own applications.

Key capabilities:

• Sandboxed cloud VMs — each agent run gets an isolated environment; no host contamination, no shared state between runs
• Named subagents — create hierarchies of agents, delegate subtasks, collect results
• Lifecycle hooks — intercept onFileChange, onCommandRun, onPRCreated, and other events to add your own logic
• Streaming — stream agent output token-by-token for real-time UIs
• Three execution modes: local (on your machine), cloud (Cursor-hosted), and self-hosted
• Token-based pricing at the same rates as Cursor IDE — no separate billing

This is aimed at developers who want coding agents that run as part of CI/CD pipelines, automated PR workflows, or custom internal tools — not just inside the Cursor IDE interface.

Prerequisites

• Node.js 18+
• A Cursor account (free tier works for development; cloud/self-hosted modes require a paid plan)
• TypeScript familiarity (the SDK is TS-first, though you can use it from plain JS)

Installation

npm install @cursor/sdk
# or
pnpm add @cursor/sdk

Your First Agent

Here’s a minimal agent that takes a task description, runs it in a sandboxed VM, and returns the result:

import { CursorAgent } from '@cursor/sdk';

const agent = new CursorAgent({
  mode: 'cloud', // 'local' | 'cloud' | 'self-hosted'
  model: 'claude-opus-4-6', // or 'gpt-4o', 'cursor-small', etc.
});

const result = await agent.run({
  task: 'Add input validation to the register() function in src/auth.ts. Ensure email is a valid format and password is at least 8 characters.',
  context: {
    repoUrl: 'https://github.com/your-org/your-repo',
    branch: 'main',
  },
});

console.log('Files changed:', result.filesChanged);
console.log('PR URL:', result.pullRequestUrl);

In cloud mode, this spins up a sandboxed VM, clones your repo, runs the coding agent against your task description, and returns structured output including changed files, test results, and (if configured) a PR URL.

Adding Lifecycle Hooks

Hooks are where the SDK gets interesting. You can intercept specific moments in the agent’s execution to add validation, logging, or custom logic:

const agent = new CursorAgent({
  mode: 'cloud',
  hooks: {
    onFileChange: async (event) => {
      // Called whenever the agent modifies a file
      console.log(`Agent modified: ${event.path}`);
      
      // You can veto the change
      if (event.path.includes('package-lock.json')) {
        return { allow: false, reason: 'Do not modify lockfiles' };
      }
      return { allow: true };
    },
    
    onCommandRun: async (event) => {
      // Called before the agent runs a shell command
      console.log(`Agent wants to run: ${event.command}`);
      
      // Block dangerous commands
      if (event.command.includes('rm -rf')) {
        return { allow: false };
      }
      return { allow: true };
    },
    
    onPRCreated: async (event) => {
      console.log(`Agent created PR: ${event.pullRequestUrl}`);
      // Trigger your own notifications, Slack messages, etc.
    }
  }
});

The onCommandRun hook in particular is a useful safety layer — it gives you a human-reviewable interception point before any shell command executes in the sandbox.

Using Named Subagents

For complex tasks, you can create hierarchies of agents. A parent agent can delegate subtasks to named child agents and wait for their results:

import { CursorAgent, Subagent } from '@cursor/sdk';

const orchestrator = new CursorAgent({ mode: 'cloud' });

const result = await orchestrator.run({
  task: 'Refactor the authentication module',
  subagents: [
    new Subagent({
      name: 'test-writer',
      task: 'Write unit tests for the existing auth functions before refactoring',
    }),
    new Subagent({
      name: 'refactor-agent',
      task: 'Refactor auth module to use the repository pattern',
      dependsOn: ['test-writer'], // runs after test-writer completes
    }),
  ],
});

Subagents run in their own isolated VMs. Results are composed back to the parent agent’s context.

Streaming Output

For real-time UIs or progress monitoring, enable streaming:

const stream = agent.stream({
  task: 'Update all API endpoints to use the new error handler middleware',
  context: { repoUrl: 'https://github.com/your-org/api-service' },
});

for await (const event of stream) {
  if (event.type === 'token') {
    process.stdout.write(event.content);
  } else if (event.type === 'fileChange') {
    console.log(`\n[Changed] ${event.path}`);
  } else if (event.type === 'complete') {
    console.log('\nAgent finished. PR:', event.result.pullRequestUrl);
  }
}

Execution Mode Comparison

Cloud mode is the most convenient for getting started. Self-hosted is available for organizations that can’t send code to external infrastructure.

Pricing

The SDK uses token-based pricing identical to Cursor IDE rates. Cloud VM time is included in token costs — you’re not charged separately for compute. Track your usage at cursor.com/dashboard.

Next Steps

• Read the Cursor SDK TypeScript documentation
• Browse the Cursor changelog SDK release notes
• Join the Cursor community forum for beta feedback and examples

The SDK is in public beta — expect breaking changes in minor versions until 1.0. Pin your version in package.json and check the changelog before upgrading in production.

Sources

1. Cursor TypeScript SDK documentation
2. Cursor blog: TypeScript SDK launch
3. Cursor changelog: SDK release
4. MarkTechPost coverage of Cursor TypeScript SDK

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260430-0800

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