Summer Engine — Claude Code MCP server: what it does, how to install
An MCP server, game-dev skills and the summer CLI in one npm package: an agent builds a multiplayer game in Summer Engine, tests it and ships it to summer.games.
claude mcp add --transport http summer https://mcp.summerengine.com/mcpWhat Summer Engine does
The hosted server sits at https://mcp.summerengine.com/mcp. One URL in the agent config, a single sign-in to a Summer account, and the agent is generating assets (images, 3D models, animation, sound, music, voices, video), browsing the asset library, planning games, running projects, the store, publishing, prices, analytics, A/B tests, the team and Studio.
Engine work goes through the local server. npx -y summer-engine@latest setup <agent> --yes needs Node 22+ and writes summer mcp into the agent config with the skills attached. That server talks to the Summer Engine app on your machine: scenes, scripts, playing the build, real keypresses, screenshots, debugger output. The CLI fetches the app itself, roughly 660 MB, free, and asks before it starts. One summer login later the same server also covers the cloud operations, so you never run two.
Skills ship in the package: movement, combat, multiplayer, VFX, audio, UI, level design. Project memory accumulates in .summer/, so a fresh agent session picks up the thread of the previous one. The hosted server carries no engine tools, so scenes and scripts are off its list — that part belongs to the local one. Six switches under Studio > Settings > Agent permissions set what an agent is allowed to touch.
What it helps with
- block out a scene, its physics and UI inside the open editor
- wire matchmaking, parties and leaderboards on Summer's networking
- smoke-test a build by playing it, pressing keys and grabbing a screenshot
- publish a build to summer.games with a private preview link
- read store page views and session length back from the game
Example prompts for the agent
- Build a small multiplayer arena in Summer Engine: movement, shooting, a lobby.
- Play the current build, take a screenshot and tell me what the debugger says.
- Publish this build to summer.games and give me the private preview link.
How to install Summer Engine
1Platform CLI: remote server
claude mcp add --transport http summer https://mcp.summerengine.com/mcp2Platform CLI
claude mcp add summer-engine -- npx -y summer-engine1Platform CLI: remote server
codex mcp add summer-engine --url https://mcp.summerengine.com/mcp2Platform CLI
codex mcp add summer-engine -- npx -y summer-engineConfig file
{
"mcpServers": {
"summer-engine": {
"url": "https://mcp.summerengine.com/mcp"
}
}
}{
"mcpServers": {
"summer-engine": {
"command": "npx",
"args": [
"-y",
"summer-engine"
]
}
}
}Config file
{
"servers": {
"summer-engine": {
"type": "http",
"url": "https://mcp.summerengine.com/mcp"
}
}
}{
"servers": {
"summer-engine": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"summer-engine"
]
}
}
}1Platform CLI: remote server
gemini mcp add -t http summer-engine https://mcp.summerengine.com/mcp2Platform CLI
gemini mcp add summer-engine npx -y summer-engineStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Summer Engine
How do I install Summer Engine in Claude Code?
Run claude mcp add --transport http summer https://mcp.summerengine.com/mcp, then open /mcp and sign in to your Summer account. This route downloads nothing.
What does Summer Engine do?
It hands the agent game-engine tools: build a scene, write a script, play the build, screenshot it, read the errors. With an account signed in it also generates assets, plans the game and publishes it to summer.games.
Does the hosted server cover engine work?
No. Assets, store, publishing and analytics run over https://mcp.summerengine.com/mcp, while scenes, scripts and playing the build need the local summer mcp server on Node 22+.
