The Summer Engine CLI (summer) installs the engine, configures your AI agent, manages projects, signs you in, and runs the MCP server. Run any command without a global install using npx:
npx -y summer-engine@latest <command>
The fastest way to get started is the one-line setup, which wires up your agent’s MCP config, installs the recommended skills, and runs diagnostics in a single step:
Configure Summer Engine for an AI agent and run diagnostics in one step. This is the recommended onboarding command. It writes the MCP server config for the agent, installs the recommended skills, and prints a doctor report.
Diagnose your setup end-to-end: Node version, CLI version, skills freshness, login, engine install, the local engine API, project memory, and MCP server boot.
summer doctor [--json]
Option
Description
--json
Print diagnostics as JSON
Run this first whenever something is not working. Each check reports OK, a warning, or a failure with a clear next step (for example, “engine not running” or “not signed in”).
Download and install Summer Engine to your system.
summer install [--path <dir>]
Option
Description
--path <dir>
Custom install directory (macOS default is /Applications/Summer.app)
Platforms: macOS and Windows. Linux users download manually from summerengine.com.What it does: Fetches the latest release, downloads the installer, and installs the app. On macOS it mounts the DMG and copies Summer.app to Applications. On Windows it runs the installer. After install, run summer login, then summer run.
Sign in to your Summer Engine account via browser OAuth.
summer login [--force]
Option
Description
--force
Re-authenticate even if already logged in
What it does: Opens your browser to the login page. After you sign in with Google, GitHub, or email, the CLI saves the token to ~/.summer/auth-token. Login is required for asset search and AI generation tools, and recommended in general. The MCP server uses a separate local token (~/.summer/api-token) for engine communication.
Check engine status, API connection, and auth state.
summer status
Reports whether you are logged in (and with which email), whether the engine is running (and which project and scene are open), and the local API port and token presence.
Launch Summer Engine, optionally opening a project.
summer run [path]
Argument
Description
path
Path to a project directory (must contain project.godot). Optional.
What it does: Finds the Summer Engine binary, spawns it with --editor, and optionally passes --path <projectPath>. Waits for the local API to respond (up to 20 seconds). If the engine is already running, it reports the current state and exits.Examples:
summer run # Launch engine (no project)summer run my-game # Launch and open my-game/summer run ./projects/racer # Launch and open a relative path
Path to a project directory (must contain project.godot)
What it does: Resolves the path and checks for project.godot. If the engine is not running, it launches with that project. If the engine is already running, it prints the path and a note: to switch projects, close the current one in the engine first or run summer run <path>.
Built-in slug (empty, 3d-basic) or any community template slug
name
Project directory name (defaults to the template slug)
Built-in templates work offline:
Template
Description
empty
Empty 3D project with a root Node3D
3d-basic
3D scene with Camera3D, DirectionalLight3D, floor mesh, and sky
Community templates clone from github.com/SummerEngine/template-*. Run summer list templates to browse them. Pass --keep-git to keep the upstream .git directory after cloning (default is to detach so you start fresh).Examples:
summer create 3d-basic my-game # Built-in templatesummer create empty # Built-in templatesummer list templates # Browse community templates
Plan the right Summer CLI/MCP workflow for an AI game-building task. Takes a goal in plain English and prints the recommended skills, MCP tool groups, host-file work, user gates, and next steps. Useful as a planning aid before you ask your agent to build something.
summer plan <goal...> [--json]
Argument / Option
Description
<goal...>
What you want to build, fix, polish, or create
--mode <mode>
Optional task mode override
--target <target>
Optional task target override
--asset-policy <policy>
Optional asset policy override
--verification <level>
Optional verification level override
--json
Print the plan as JSON
Example:
summer plan make a small arena shooter
This is the CLI surface of the same router exposed to agents as the summer_start_game_task MCP tool.
Inspect a project’s durable memory in its .summer directory. Project memory is where agents store the game brief, art and audio bibles, the build plan, and locked facts like voice IDs and world canon.
What it does: Starts the MCP server on stdio. Your IDE or agent invokes this automatically when it loads the MCP config you wrote with summer setup, so you rarely run it by hand. Exposes 44 tools for scene editing, debugging, project context, asset search, and AI generation. See the Tools Reference.There is also a lower-level summer mcp setup <agent> subcommand that writes only the MCP config (no skills, no diagnostics). Prefer the top-level summer setup <agent> for onboarding.
Install and manage best-practice guides for AI agents building games. Skills are Markdown files that teach the agent patterns for scene composition, character controllers, asset generation, debugging, and more.
summer skills list # List available skillssummer skills install <name> --agent <a> # Install one skill for an agentsummer skills install --recommended --agent <a> # Install the recommended setsummer skills install --all --agent <a> # Install every skillsummer skills info <name> # Show description and preview
Option
Description
--agent <agent>
Target agent (e.g. claude-code, cursor, codex) so the skill installs where that agent auto-discovers it
--recommended
Install the recommended skill set
--all
Install every available skill
--force
Overwrite existing skill content on re-install
Most users never call this directly: summer setup <agent> --yes installs the recommended skills for you. See Skills for the full catalog and the 20+ categories.
