Anysphere, the creator of the AI-powered code editor Cursor, officially launched the Cursor SDK in public beta on Wednesday, April 29, 2026.
The SDK allows developers to programmatically build and deploy AI coding agents using the same core infrastructure—runtime, harness, and models (like Composer 2)—that powers the Cursor desktop application, CLI, and web interface.
1. Key Features of the Cursor SDK
The SDK shifts Cursor from an interactive tool into “deployable infrastructure,” allowing agents to be integrated directly into backend services or CI/CD pipelines.
- TypeScript Library: Developers can get started with a single command:
npm install @cursor/sdk. - Sandboxed Cloud VMs: Agents can run in isolated, dedicated virtual machines in Cursor’s cloud, or locally on the developer’s machine.
- Multitasking & Subagents: The SDK supports async subagents, allowing a primary agent to parallelize requests and break down massive tasks into smaller chunks for a “fleet” of subagents to tackle simultaneously.
- Durable Agent Lifecycle: The API includes first-class controls for agent persistence, including archiving, unarchiving, and permanent deletion of agent sessions.
- Token-Based Pricing: Unlike the flat subscription for the IDE, the SDK is billed based on standard consumption-based token pricing.
2. Sample Implementation
The SDK allows an agent to be invoked with just a few lines of code. Below is the minimal example provided in the official release:
TypeScript
import { Agent } from "@cursor/sdk";
const agent = await Agent.create({
apiKey: process.env.CURSOR_API_KEY!,
model: { id: "composer-2" },
local: { cwd: process.cwd() },
});
const run = await agent.send("Summarize what this repository does");
for await (const event of run.stream()) {
console.log(event);
}
3. Cursor 3.1 & “Composer 2” Integration
The SDK release coincides with the stable rollout of Cursor 3.1, which features Composer 2—Cursor’s third-generation proprietary model built on Moonshot AI’s Kimi K2.5 foundation.
- Multi-root Workspaces: Agents can now span changes across multiple repositories simultaneously (e.g., updating an API contract in the backend and its implementation in the frontend).
- Tiled Agent Layout: For IDE users, a new tiled interface allows developers to run and monitor multiple agents side-by-side in real-time.
- Interactive Canvases: Agents can now respond by creating interactive dashboards, custom UIs, and to-do lists instead of just plain text or code blocks.
4. Strategic Context: The $60 Billion Valuation
The SDK launch comes amidst reports that SpaceX (via its xAI division) has reached an agreement to acquire Anysphere for $60 billion, following a massive $2.3 billion Series D funding round in late 2025 led by Thrive Capital and Nvidia. By opening its SDK, Cursor is positioning itself as the foundational operating system for the “agentic coding” era, competing directly against GitHub Copilot’s Extension API and Claude Code.