cursor-sdk

Cursor SDK

The Cursor TypeScript SDK (@cursor/sdk) runs Cursor agents programmatically. The same interfaces drives the local runtime (agent runs on your machine against your files) and the cloud runtime (agent runs on Cursor-hosted or self-hosted infrastructure against a cloned repo and opens PRs).

Use this skill to help someone bootstrap a working integration quickly and avoid the handful of traps that bite new users. Canonical docs live at https://cursor.com/docs/api/sdk/typescript; this skill only adds decision-making, failure-mode prevention, and ready-to-extend patterns.

Voice and Posture

This skill helps the user build with the SDK. It is not the place to validate, congratulate, or sell the SDK as a choice. The user's intent is the input; your job is execution.

• When the user names the SDK explicitly (says "Cursor SDK", @cursor/sdk, Agent.create, Agent.prompt, etc.): assume they know what the SDK is and have decided to use it. Skip framing, skip pep talk, go straight to producing the integration. No "good news", no "the SDK is perfect for this", no "this is almost exactly the pattern X is designed for".
• When the user describes a problem the SDK fits but doesn't name it ("I want a bot that reviews my PRs", "I want a script that asks Cursor questions about my repo"): the SDK isn't yet a confirmed choice. Surface it as a question, briefly, then wait: "The Cursor SDK is what I'd reach for here — want me to design it that way, or do you have a different runtime in mind?" If they confirm, proceed. If they push back or want options, give options.
• In either case, don't restate the user's intent back to them. They know what they want. Get to the design.

Avoid these specific openers (and their close cousins):

• "Good news: this is exactly the pattern…"
• "The SDK is built for this shape."
• "Great, you've come to the right place."
• "This is almost exactly the X the SDK is designed for."
• Any lede that compliments the user's choice or restates their goal in flattering terms.

Prefer:

• Open with the design decision or the first thing they need to know.
• If you genuinely have a design choice to flag (local vs cloud, prompt vs send, sync vs stream), name it in one sentence and explain why; don't preface it with validation.

When to open a reference file

Keep this page short. Read a reference file only when the user's task clearly falls inside it:

If the user is...	Read
Picking between local and cloud runtime, or not sure which they should use	references/runtime-choice.md
Debugging auth (401s, "Missing CURSOR_API_KEY", team-vs-user keys, local vs prod)	references/auth.md
Handling errors, retries, rate limits, CursorAgentError, result.status === error	references/error-handling.md
Consuming streams, picking event types, cancelling, or deciding stream vs wait	references/streaming.md
Configuring MCP servers (HTTP, stdio, cloud vs local transport, auth injection)	references/mcp.md
Using sub-agents, resume, artifacts, listing/inspecting agents, Agent.messages	references/advanced.md
Building a specific integration (CI review bot, scheduled triage, chat, webhook)	references/patterns.md

Everything below is the minimum needed for 80% of tasks.

The Three Invocation Patterns

Almost every SDK integration collapses to one of three shapes. Pick the one that fits the job, don't mix them.

1. Agent.prompt(...) — one-shot

import { Agent } from "@cursor/sdk";

const result = await Agent.prompt("Refactor src/utils.ts for readability", {
  apiKey: process.env.CURSOR_API_KEY!,
  model: { id: "composer-2" },
  local: { cwd: process.cwd() },
});
console.log(result.status, result.result);

Use for fire-and-forget scripts, GitHub Actions steps, or any "send this prompt, get a result, exit" flow. No streaming, no follow-ups, no cleanup to remember. If you're reaching for this and then immediately resuming, you wanted pattern 2 instead.

2. Agent.create(...) + agent.send(...) — durable with follow-ups

import { Agent } from "@cursor/sdk";

const agent = Agent.create({
  apiKey: process.env.CURSOR_API_KEY!,
  model: { id: "composer-2" },
  local: { cwd: process.cwd() },
});

try {
  const run = await agent.send("Find the bug in src/auth.ts");
  for await (const event of run.stream()) {
    if (event.type === "assistant") {
      for (const block of event.message.content) {
        if (block.type === "text") process.stdout.write(block.text);
      }
    }
  }
  const result = await run.wait();

  // Follow-up keeps full conversation context.
  const run2 = await agent.send("Now write a regression test for it");
  await run2.wait();
} finally {
  await agent[Symbol.asyncDispose]();
}

Use when you need streaming, multi-turn conversation, or lifecycle operations (cancel, status listener). This is the shape of most non-trivial integrations.

3. Agent.resume(...) — pick up an existing agent later

const agent = Agent.resume(previousAgentId, {
  apiKey: process.env.CURSOR_API_KEY!,
  model: { id: "composer-2" },
  local: { cwd: process.cwd() },
});
const run = await agent.send("Also update the changelog");
await run.wait();

Use across process boundaries: a cron that continues last night's cleanup, a webhook that extends a user's agent, an interactive CLI that reloads conversation state. Inline mcpServers are not persisted across resume — pass them again on the resume call.

Top Five Traps (read these before writing code)

These trip up almost every new integration. They're all easy to prevent once you know about them.

1. Missing cloud: { repos } silently defaults to local

AgentOptions doesn't require local or cloud; if you omit both, the SDK selects the local runtime. The trap: if you intended a cloud agent and forgot the cloud: field, you get a local agent silently — no error, just a local agent ID and a local executor. Always pass cloud: { repos } explicitly when you want cloud, and pass local: { cwd } explicitly for local even though it's the default. Picking the right runtime: see references/runtime-choice.md.

2. Two different kinds of failure, one instinct to conflate them

try {
  const run = await agent.send(prompt);
  const result = await run.wait();
  if (result.status === "error") {
    // Agent started but failed mid-run. Inspect transcript, git state, tool outputs.
    console.error(`run failed: ${result.id}`);
    process.exit(2);
  }
} catch (err) {
  if (err instanceof CursorAgentError) {
    // Didn't start. Auth, config, network. Fix environment, retry.
    console.error(`startup failed: ${err.message}, retryable=${err.isRetryable}`);
    process.exit(1);
  }
  throw err;
}

CursorAgentError thrown → the run never executed (auth, config, network). result.status === "error" → the agent did work, and that work failed. Different fixes, different exit codes, different observability. Full taxonomy in references/error-handling.md.

3. Forgetting await agent[Symbol.asyncDispose]() leaks resources

The SDK holds handles to local executors, persisted run stores, and cloud API clients. Not disposing means leaked child processes, open databases, and in long-running services, memory growth. Always dispose in a finally, or use Agent.prompt() (disposes for you), or use the await using syntax if your tsconfig targets it:

await using agent = Agent.create({ /* ... */ });

4. Streaming is optional but wait() is (almost) required

run.stream() is how you observe; run.wait() is how you get the terminal result. You can skip streaming, but skipping wait() means you can't tell whether the run finished, errored, or was cancelled, and you'll leak the run's internal watchers. Always call wait(). If you don't want live output, just call wait() alone. See references/streaming.md for event type reference.

5. Not every run operation is supported on every runtime

Run exposes four operations — stream, wait, cancel, conversation — and the runtime may or may not support each. Always guard with run.supports("...") before calling, rather than assuming:

if (run.supports("cancel")) await run.cancel();
if (run.supports("conversation")) console.log(await run.conversation());

Current gap worth knowing about: detached/re-hydrated runs (you got the handle from Agent.getRun(...) after the live event store has closed) may not support stream() and may have empty conversation(). run.unsupportedReason(op) tells you why. Cloud run.conversation() IS supported — it accumulates best-effort from the stream.

Local vs Cloud, in one sentence each

• Local — runs on the caller's machine against cwd, reuses their environment and credentials, good for dev loops and CI that already has a repo checkout.
• Cloud — runs on a Cursor-hosted VM against a freshly cloned repos[].url, good for long jobs, fire-and-forget automation, and opening real PRs (autoCreatePR: true).

Decision tree, capability differences, and capability gaps (artifacts, cancel, MCP transport): references/runtime-choice.md.

Auth, minimum viable

export CURSOR_API_KEY="cursor_..."  # user API key or team service-account key

The SDK reads CURSOR_API_KEY if apiKey isn't passed. Both user keys (from https://cursor.com/dashboard/cloud-agents) and team service-account keys (Team Settings → Service accounts) work for local and cloud runs.

If you're seeing 401s, the usual suspects are: key pasted with surrounding whitespace, key minted against a different environment, or the key belongs to a user without repo access for a cloud run. Full troubleshooting: references/auth.md.

Model Selection

import { Cursor } from "@cursor/sdk";

const models = await Cursor.models.list({ apiKey: process.env.CURSOR_API_KEY! });

composer-2 is the current default for most integrations. { id: "auto" } lets the server pick. Model IDs change; don't hardcode exotic ones without calling Cursor.models.list() first to confirm the caller has access.

Model is required for local, optional for cloud (the server resolves a default from the caller's account).

Production Best Practices

Apply these to any integration that runs unattended:

1. Wrap every Agent.create / Agent.prompt / Agent.resume in a try/finally with [Symbol.asyncDispose](). Non-negotiable.
2. Distinguish startup failures from run failures — exit code 1 for CursorAgentError, exit code 2 for result.status === "error", exit code 0 only for finished. Makes CI failures actually readable.
3. Log run.id and agent.agentId immediately after send() before streaming. If the stream hangs, the IDs are what you need to investigate in the dashboard or via Agent.getRun(...).
4. Respect error.isRetryable — it's the backend telling you the specific failure is safe to retry. Blind retries can cause duplicate cloud runs; respecting the flag doesn't.
5. Use local: { settingSources: [] } (default) unless you need ambient config. Opting into "all" loads project/user/team/MDM settings from the caller's environment, which is rarely what you want from a service. Note: settingSources lives under local, not at the top level; it has no effect on cloud agents (cloud always honors team/project/plugins).
6. For cloud agents in CI, set skipReviewerRequest: true unless a human should be paged — it suppresses the reviewer-request step and keeps PR notifications quiet.
7. Always pass apiKey explicitly in shared-infrastructure code instead of relying on the env var. Makes the credential dependency obvious and prevents cross-tenant mistakes.
8. Prefer Agent.prompt(...) for true one-shots — it disposes for you and is harder to leak.

Longer version with examples: references/patterns.md.

Observing a Run You Didn't Launch

You can inspect any agent/run by ID later:

// Cloud: IDs that start with "bc-" auto-route to the cloud API
const info = await Agent.get("bc-abc123", { apiKey });
const run = await Agent.getRun(runId, { runtime: "cloud", agentId: "bc-abc123", apiKey });

// Local: you need the cwd where the agent was created
const localInfo = await Agent.list({ runtime: "local", cwd: process.cwd() });

A cloud bc--prefixed agent ID is not a run ID. If you only have a run ID (from a log or a webhook), pass it to Agent.getRun with the runtime hint; don't confuse the two.

Offering a Canvas

If the user's integration monitors, lists, or visualizes agents — dashboards of active runs, conversation replays, tool-call timelines — offer a Cursor Canvas to render it. If they accept, defer entirely to the canvas skill.

What This Skill Doesn't Cover

• The Cloud Agents REST API (/v1/agents/*). If the user needs a non-TS client, the REST API is documented separately at https://cursor.com/docs/cloud-agent/api; check there for current capabilities before assuming parity with the SDK.
• .cursor/hooks.json hooks. Cloud agents execute them but the SDK doesn't manage them; see Cursor's Hooks docs.
• Private workers / self-hosted cloud. Send users to the Private Workers docs.
• Python / non-TS SDKs. There is no first-party SDK in other languages at time of writing; REST is the portable option.