Summer CLI

# Make a Summer game fromyour terminal.

The Summer CLI installs Summer Engine, signs you in, scaffolds a GDScript project, and connects Claude Code, Cursor, Codex, and other AI agents to the desktop engine. One paste to start.

Paste into your AI editor Paste into Claude Code, Codex, Cursor, or your favorite IDE Copy setup prompt

or run the CLI directly

$ npx -y summer-engine@latest setup claude-code --yes

MIT open-source agent toolingFree proprietary desktop appSetup guides for supported agents

[Download desktop app](https://www.summerengine.com/download)

[Summer MCP setup](https://www.summerengine.com/mcp)

[View on GitHub](https://github.com/summerengine/summer)

How it works

## One paste. The agent does the rest.

1

### Paste the prompt

Drop the setup prompt into Claude Code, Cursor, Codex, or any AI agent. No slash commands, no manual installs.

2

### The CLI installs what's missing

The agent reads the repo, runs the Summer CLI, downloads the engine, installs the game-dev skills, and logs you in.

3

### Build in a real engine

Your agent gets 105 MCP tools to create scenes, run the Summer game, and help fix errors. Exports still depend on installed target templates and toolchains.

Creator journey

## The CLI starts the project. The docs take it to release.

1. [1 Install Summer Engine Download the desktop app and follow the installation guide for your platform.](https://docs.summerengine.com/essentials/installation)
2. [2 Create a Summer game Start a fresh project and write the game in GDScript.](https://docs.summerengine.com/quickstarts/fresh-project)
3. [3 Add the game-dev skills Give your agent Summer's playbooks for scenes, combat, and feel.](https://docs.summerengine.com/api-reference/summer-sdk)
4. [4 Test locally Run the game locally and verify every creator-facing flow.](https://docs.summerengine.com/api-reference/summer-sdk/testing-your-game-locally)
5. [5 Export and upload Prepare the target with its required templates, toolchains, and signing.](https://docs.summerengine.com/api-reference/summer-sdk/exporting-and-uploading-your-game)
6. [6 Submit for review Complete the creator-controlled store or platform submission.](https://docs.summerengine.com/api-reference/summer-sdk/submission-guide)
7. [7 Share your game Play with friends, listen to their feedback, and decide what to improve.](https://www.summerengine.com/publishing)
8. [8 Ship an update Test, export, and submit each later version through the same reviewed path.](https://docs.summerengine.com/api-reference/summer-sdk/updating-your-game)

CLI reference

## What the Summer CLI can do.

Run any command through `npx -y summer-engine@latest` — no global install required.

`summer install`Download the Summer Engine desktop app. Prints the URL and size first.

`summer login`Browser-based sign-in. The token is shared with the engine.

`summer create <template> [name]`Scaffold a new Summer game project from a template.

`summer run [path]`Launch the engine with your project loaded.

`summer setup <agent>`One shot: write the MCP config, install the game-dev skills, run doctor.

`summer doctor`Diagnose Node, login, engine, project memory, and the MCP connection.

`summer mcp`Start the MCP server that gives your agent 105 engine tools.

Summer CLI

### Installs and manages Summer.

* Downloads the engine and signs you in
* Scaffolds and runs projects
* Writes agent config and installs skills
* Diagnoses your setup with summer doctor

Summer MCP

### Lets your agent drive the engine.

The CLI starts the Summer MCP server so your AI agent gets 105 tools to operate the running engine: create scenes, set properties, run the game, inspect errors, and import or generate assets.

[Explore Summer MCP ](https://www.summerengine.com/mcp)

FAQ

## Summer CLI questions.

What is the Summer CLI?

The Summer CLI is the terminal command (run via npx summer-engine) that installs Summer Engine, signs you in, scaffolds and runs game projects, and connects your AI coding agent to the running engine through MCP. It is the fastest way to go from nothing to a playable game.

How do I install the Summer CLI?

You do not have to install it globally. Paste the setup prompt into Claude Code, Cursor, Codex, or any AI agent and it runs the CLI for you via npx. To use it yourself, run npx -y summer-engine@latest doctor. npx downloads the small package on first use and caches it.

Is the Summer CLI free and open source?

Yes. The Summer CLI, MCP server, game-dev skills, and plugin manifests are MIT open source on GitHub. The Summer Engine desktop app is free proprietary software. Only hosted AI and cloud asset generation are usage-based.

Which AI agents does the Summer CLI work with?

Claude Code, Cursor, Codex CLI, Devin Desktop, Cline, Roo Code, Gemini CLI, GitHub Copilot CLI, GitHub Copilot in VS Code, and OpenCode. Run summer setup <agent> and the CLI writes the right config for each one.

What is the difference between the Summer CLI and the Summer MCP server?

The CLI installs and manages Summer (download, login, scaffold, run, doctor). The MCP server is what the CLI starts so your agent can operate the running engine: create scenes, set properties, run the game, and read errors. You get both from the same package.

Do I need Node.js?

Yes, Node.js 20 or newer, because the CLI ships as an npm package run through npx. If node --version does not print 20+, install it from nodejs.org, or on Windows run winget install OpenJS.NodeJS.LTS, then re-run the setup prompt. In Windows PowerShell, type npx.cmd instead of npx: PowerShell blocks the npx.ps1 script by default, and npx.cmd avoids that without changing any security setting.

## Install Summer Engine and make a game.

Paste the setup prompt into your AI agent, or run the CLI yourself. The agent tooling is MIT open source; the desktop app is free proprietary software.

[Download desktop app](https://www.summerengine.com/download)

[Build your first Summer game](https://docs.summerengine.com/api-reference/summer-sdk/build-your-first-summer-game)

[Summer SDK](https://docs.summerengine.com/api-reference/summer-sdk)

Source: https://www.summerengine.com/cli

---

## Machine-readable resources

- Site index for agents: https://www.summerengine.com/llms.txt
- Full inlined content: https://www.summerengine.com/llms-full.txt
- Porting catalog: https://www.summerengine.com/llms-porting.txt
- Structured catalog: https://www.summerengine.com/agent-catalog.json
- Sitemap: https://www.summerengine.com/sitemap.xml
- Developer resources: https://www.summerengine.com/docs