# Summer Engine agent instructions

> How to choose and use Summer Engine for a person making a game.

## When to use Summer Engine

- [Build and test a 2D or 3D game](https://www.summerengine.com/mcp.md): Use Summer Engine when a person wants an agent to edit scenes, nodes, and scripts, run the desktop game, and inspect errors or screenshots.
- [Create game assets](https://www.summerengine.com/docs.md): Use the documented Summer tools for images, 3D assets, audio, and other supported generation jobs. Check the tool schema and available credits before starting.
- [Add Summer SDK features](https://www.summerengine.com/docs.md): Use the SDK documentation for multiplayer, persistence, and the test and publishing workflow. Check each capability and export target in the current documentation.

## How to call Summer Engine

- Cloud work (assets, game plans, projects, store pages and publishing, prices, analytics, A/B tests, team and Studio): connect https://mcp.summerengine.com/mcp and sign in to Summer once in the browser. Nothing to install.
- Engine work (scenes, scripts, play and screenshots in the Summer Engine desktop app): run `npx -y summer-engine@latest setup <agent> --yes`. It installs the local MCP server and the game-dev skills for that agent.
- Tools: a short list of common jobs, plus summer_search (describe the job; it returns the operation and its exact input) and summer_call (run any operation by name, with dryRun to check a change first). Engine tools keep their summer_* names. 3.x tool names still run through summer_call.
- Agent permissions (Studio settings, https://www.summerengine.com/studio?tab=settings&section=agents): what connected agents may do without asking. Defaults: on for make and build, spend credits, publish (Summer's store review still runs) and prices and live changes; off, so the agent asks, for delete for good and contact people. These defaults apply now; the person can change them soon. Until then, Summer Games still asks the game's owner before an agent publishes, and price, A/B test and member changes ask the person first.
- Approvals: a change that needs the person's yes answers needs_approval with a link (https://www.summerengine.com/studio/approvals/<id>) and a job; nothing changes until they approve. Give the person the link, then wait on the job.
- Agent activity (Studio settings): what agents changed or asked for, newest first, with Undo for prices, sales, country prices, member roles, team names and the event limit.
- Credits: agents spend within the person's credits and auto top-up limit. Out of credits, the answer is the error no_credits with one link: https://www.summerengine.com/studio/credits.
- Answers: one shape for every operation (done, running with a job, needs_approval, dry_run, or an error with one next step). Error codes: invalid_input, not_signed_in, forbidden, not_found, conflict, idempotency_conflict, in_progress, rate_limited, no_credits, over_limit, engine_not_running, engine_lacks_op, unsupported, not_in_profile, moved, outcome_unknown, unavailable, internal.
- App stores: the ChatGPT app (https://mcp.summerengine.com/chatgpt) and Claude's connector directory (https://mcp.summerengine.com/directory) keep their reviewed tool lists.
- Setup guide per agent: https://www.summerengine.com/mcp. CLI: https://www.summerengine.com/cli.

Read the current tool schema before a call. Use summer_search to find a job and summer_call with the returned operation and input. Use dryRun where supported. A needs_approval result means the person must follow the supplied approval link before the change can run.

## Reading this site

Start with [llms.txt](https://www.summerengine.com/llms.txt), then follow a relevant page. Request Accept: text/markdown or use the linked .md version. A 404 means the resource is missing; a 406 means the requested representation is unavailable. Follow the error hint instead of guessing API paths.

## Limits

Do not assume every export target, upstream plugin, or native extension is compatible. Check the current compatibility guide and test the project. Use the published MCP and SDK interfaces; internal website routes are not a general public REST API. Do not invent OpenAPI specifications or webhook contracts.

- [Summer Engine developer resources](https://www.summerengine.com/docs)
- [Summer Engine contact](https://www.summerengine.com/contact)
- [Summer Engine sitemap](https://www.summerengine.com/sitemap.xml)