arnesto: Skill for Cursor

.cursor/skills-cursor/sdk/SKILL.md

sdk is a skill for Cursor from saski/arnesto. It costs 202 tokens per session (4,623 once invoked), scanned A, original, Unlicense.

A software development kit for building programs that start and control Cursor agents from TypeScript or Python.

In plain words
What is it for?
Creating agents, sending prompts, continuing runs, and using local or cloud-based agent sessions.
Why use it?
It removes the need to manually operate an agent when you want agent work inside an app, script, or automation.

Skill for Cursor

Written for Cursor: installed under .cursor/. Also seen: mentions Cursor.

This is saski/arnesto's own configuration. It tells Cursor how to work on arnesto itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything arnesto configures →

Reuse

Borrowing it

Nothing to install: this file belongs to saski/arnesto. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/saski/arnesto/main/.cursor/skills-cursor/sdk/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/saski/arnesto

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for sdk

README.md
[![agentmods](https://agentmods.dev/badge/skills/saski/arnesto/sdk.svg)](https://agentmods.dev/skills/saski/arnesto/sdk)
Your own site
<a href="https://agentmods.dev/skills/saski/arnesto/sdk"><img src="https://agentmods.dev/badge/skills/saski/arnesto/sdk.svg" alt="Measured on agentmods" height="20"></a>
Per session 202 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,623 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00202 $0.04623
Opus 5 $0.00101 $0.02312
Sonnet 5 $0.00040 $0.00925
Haiku 4.5 $0.00020 $0.00462

Measured 3d ago against content hash 0db41158a6b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

sdk scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • sdk — 100% identical, 0 lines differ
.cursor/skills-cursor/sdk/SKILL.md · 381 lines

How it starts

The opening of the file, as written. The whole thing — 381 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cursor SDK

The Cursor SDK runs Cursor agents programmatically. Two language variants share the same concepts:

Both are in public beta and follow the same AgentRun model across local (runs on the caller's machine against cwd) and cloud (runs on a Cursor-hosted VM against a cloned repo) runtimes.

Use this skill to help someone bootstrap a working integration quickly and avoid the traps that bite new users. The canonical docs cover the full reference; this skill adds decision-making, failure-mode prevention, and ready-to-extend patterns on top.

Pick the language

Decide before writing any code. The wrong choice means rewriting the whole integration. Order:

  1. The user named it. @cursor/sdk, cursor-sdk, cursor_sdk, npm install, pip install, import { Agent } from "@cursor/sdk", from cursor_sdk import - go with what they named.
  2. The codebase signals it. pyproject.toml / requirements.txt / uv.lock / .py files → Python. package.json / tsconfig.json / .ts files → TypeScript. If the integration will live in a polyglot repo, ask which subdirectory it goes into.
  3. No signal either way. Ask one short question and wait: "TypeScript or Python?" Don't pick for them.

The rest of this skill shows TypeScript and Python side by side. Concepts are identical; syntax differs - camelCase vs snake_case, async-by-default vs sync-default-with-async-mirror, await using vs with.

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, 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.

Read the full file on GitHub · 381 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 381 lines · 202 tokens per session scan A 0db41158a6b4

Subscribe to this mod's changes

sdk is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 202 tokens to every session and 4,623 once invoked, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.