Summer Engine MCP guide
How to make games for free with local LLMs in Summer Engine
Run a free local model — Ollama, LM Studio, or Goose — and build real games in Summer Engine through MCP. No subscription; your GPU does the thinking. Summer Engine is the desktop game engine; Local LLMs drives it through MCP with a model running on your own hardware.
Summer is free for MCP use
Download the desktop engine and connect it to your agent. The model runs on your own hardware, with no AI subscription and no per-message cost.
Open Local LLMs
Run a free local model on your own GPU. The setup writes the MCP config so {agentLabel} can drive the engine directly.
Run a Summer game
The local model writes code. Summer Engine shows the Summer game, runs Play mode, and helps inspect errors. Export still requires the target templates and toolchains.
Install
Connect Summer to Local LLMs
- 1
Install Summer Engine
Downloads the desktop engine app, about 1 GB. Skip it if Summer Engine is already installed, or if you only need assets and video for a game built in another engine.
- 2
Sign in
Opens your browser once. The CLI and the engine share the session.
- 3
Connect Local LLMs
Writes the summer-engine MCP config and installs the Summer game-dev skills.
- 4
Restart and build
Open LM Studio, toggle on the summer-engine MCP server in the Program tab, and raise the loaded model's context length to 32k or higher.
Local setup notes
The 2026 specifics.
Easiest: LM Studio
One app for the model and the MCP host. The setup command above writes the config; pick a model, raise its context to 32k+, and build. See the LM Studio guide for details.
Terminal: OpenCode + Ollama
The most common 2026 pairing. Ollama serves the model, OpenCode is the agent. Start Ollama with OLLAMA_CONTEXT_LENGTH=65536 — the 4k default silently breaks MCP. See the Ollama guide.
What to run
gpt-oss-20b on 12–16 GB of VRAM, Qwen3-Coder-30B or Gemma 4 27B on 24 GB, Q4_K_M quantization or better. Engine control and asset search are free; cloud generation uses credits.
Why this matters
Local LLMs runs free on your hardware. Summer Engine shows the game.
A capable local model can operate a real engine through MCP. It opens scenes, places objects, runs the project and reads errors. Your GPU does the thinking, with no subscription and no per-token bill, and your prompts never leave your machine.