Free · open source · any model

Small agent.
Takes on the big ones.

Stoat is an AI coding agent for VS Code that works with the model you choose, checks its own work with your build and tests, and lets you Keep or Undo every change.

Install for VS Code Cursor · Windsurf · VSCodium

No account, no telemetry Runs fully offline MIT licensed

Stoat · my-app

Add input validation to the signup form

Added validation to SignupForm.tsx with an error under each field, and a test for empty emails.

SignupForm.tsx+18−2

signup.test.ts+6−0

Checked: Build passed · 12/12 tests passed

2 files changed +24 −2Undo allKeep all

Works with ClaudeGPTGeminiDeepSeekMistralGrokOpenRouterOllamaLM Studio

See it in action

A real project, start to finish

Screenshots from Stoat building an ASP.NET Core e-commerce API: planned first, then built step by step, with every change waiting for review.

Stoat in VS Code: the editor shows a new file as a green diff; the Stoat panel lists edits with Review, Undo and Keep buttons, a dotnet build command waiting for approval, and a summary of 21 files changed with Build passed and Plan step 4 of 7. — The diff opens in the editor while the panel tracks each edit. **dotnet build** waits for your Run, and the summary shows **21 files · Build passed** with the plan at step 4 of 7.

An entity-relationship diagram in the plan linking User, Category, Product, Order, CartItem and OrderItem, next to the Stoat panel writing order service files. — Plan mode draws the data model before any code is written, and Build works through it on the right.

A Markdown plan titled E-commerce API: Core Domain, with Goal, Approach and Design sections that reference the project's existing classes. — The plan reads your code first, so it extends what's there and names the gaps it will fix.

Stoat's model provider settings: DeepSeek, Anthropic, Google Gemini, Mistral, xAI, Groq, OpenRouter, Together AI, Fireworks, OpenAI and Azure OpenAI, plus Ollama and LM Studio on your machine and a custom server. — **Eleven cloud providers**, Ollama and LM Studio with no key, or any OpenAI-compatible server. Keys stay in VS Code's secret storage, never in settings files.
DeepSeekClaudeGeminiOpenAIMistralGrokGroqOpenRouterOllama · localLM Studio · local

Why developers switch

Code you can trust, from the model you choose

66% of developers say AI code is "almost right, but not quite" (Stack Overflow 2025). Stoat is built around fixing that.

Checks its own work

After editing, Stoat runs your project's build and tests. If something fails, the agent reads the output and fixes it before it says "done".

Detected for .NET, Node, Rust, Go, Java and Python, or your own commands
The result in the review: "✓ Build passed · 12/12 tests"

✗1 of 12 tests failed · the agent is fixing itattempt 1

expected "Email is required" received undefined

Build passed · 12/12 tests passedattempt 2

Review, don't babysit

The agent works without stopping at every file. When it's done, keep what's good and undo what isn't: per edit, per file, or everything.

Exact undo that never overwrites your own later edits
Commands always wait for your approval

3 files changed +42 −7Undo allKeep all

Program.cs+30−5UndoKeep

UserService.cs+10−2UndoKeep

Helper.cs+2−0UndoKeep

Your key, your model, your cost

No subscription and no lock-in. Use any provider with your own key and switch models per message. Cost is shown on every reply, and a budget per task stops the agent before it spends more than you allowed.

Any OpenAI-compatible API, plus Claude and DeepSeek natively
Or run fully local with Ollama / LM Studio

ClaudeGPTGeminiDeepSeek MistralGrokQwen · localOllama · offline

This task: $0.004 · budget $0.10cost per reply

Tab autocomplete that works offline

One click downloads a small coder model (about 1 GB) that runs on a normal laptop. Suggestions are free, private, and keep working without internet.

Sized to your machine: 1.5B on 16 GB, bigger with more memory
Or use Codestral, DeepSeek and other cloud models

function isValidEmail(email: string) { return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email); }

qwen2.5-coder:1.5b on this computerTab to accept

Plan before building

Plan mode asks what it needs to know, then writes an editable Markdown plan that Build follows step by step.

MCP servers

Add a browser, GitHub, library docs or any MCP server, or import the ones you use in Cursor and Claude.

Web pages and search

Reads documentation and issues from the web, and never reaches your own computer or local network.

Safe by default

Only your open folder, no shell, allow-listed commands, secrets redacted, an audit log of everything it did.

Private

No account, no telemetry, no Stoat server. Your code goes only to the provider you pick, or nowhere.

Nothing to set up

The engine ships inside the extension and starts by itself. Connect a model in the panel and go.

Compare

How Stoat compares

The big tools have more power and their own models. Stoat is free, open, private and model-agnostic, and it checks its own work before handing it back.

	Stoat	Cursor	Claude Code	Devin Desktop (Windsurf)
Price	Free; pay your provider	$20–$200 / month	$20–$200 / month or API	$20–$200 / month
Any model, your key	✓	✗	✗ Claude	✗
Local / offline	✓	✗	Workarounds only	✗
Open source	✓ MIT	✗	✗	✗
Automatic build + tests	✓	On request	On request / hooks	On request
Background agents	✗	✓	✓	✓

Full comparison, with sources

Why a stoat?

200 grams. Takes on prey ten times its size.

Stoat is a small, open project built to compete with the big, closed coding tools: no subscription, no lock-in, and nothing changes in your code without your say.

Guides

Set up Stoat with the model you already use

DeepSeek in VS Code

A capable coding agent for a few cents a day.

Read the guide

Local agent with Ollama

Free, private, offline. Your code never leaves your machine.

Read the guide

Claude API in VS Code

Use your Anthropic key, and why a Pro subscription can't be used.

Read the guide

Gemini, Groq, OpenRouter

Any OpenAI-compatible provider in two minutes.

Read the guide

An open-source Cursor alternative

The agent workflow in the VS Code you already have.

Read the guide

FAQ

Questions

Is Stoat free?

Yes. Stoat is free and open source (MIT). You pay only your model provider for what you use, or nothing with a local model through Ollama or LM Studio.

How is Stoat different from Cursor or Claude Code?

Stoat is a free, open-source VS Code extension that works with any model using your own key, including local models, with no account or subscription. It builds and tests its own changes before handing them back, and you can cap the cost of each task. Cursor and Devin Desktop are their own editors with subscriptions, and Claude Code uses Claude models. See the full comparison.

Which AI models does Stoat support?

Anthropic Claude, OpenAI, Google Gemini, DeepSeek, Mistral, xAI Grok, Groq, OpenRouter, Together, Fireworks, Azure OpenAI, local models through Ollama or LM Studio, and any OpenAI-compatible API. Agent and Plan modes need models that support tool calling.

Does my code leave my machine?

Only to the model provider you choose, directly from your machine. Stoat has no server and no telemetry. With a local model, nothing leaves your computer.

Does Stoat support MCP servers?

Yes. Add servers in Settings → MCP servers (presets for a Playwright browser, Context7 docs and GitHub), import the ones you use in Cursor, Claude Desktop, Claude Code, Windsurf or VS Code, or add any local or remote server. MCP tools ask before they run unless you trust the server.

Can I use my Claude Pro or Max subscription?

No. Anthropic allows subscription logins only in Claude.ai and Claude Code. Other tools, including Stoat, need an API key from console.anthropic.com or Claude through AWS Bedrock, Google Vertex or Microsoft Foundry.