Manse

Open-source motion games, authored in Codex and played in the browser.

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Short description

Manse turns Codex into an open studio for camera-based active games. A creator describes a game in plain language, uses the Manse Creator plugin to generate a self-contained Site around a strict declarative pack, previews it with a simulator or on-device camera, validates safety and provenance, and publishes an independent ChatGPT Site. The Showcase is a reviewed index of public manifests, so creators keep their code, hosting, and license while players open normal links without a Manse account.

Inspiration

Camera-based active-play systems can make a television, tablet, laptop, or phone feel like a game console, but their creation and distribution ecosystems are usually closed. I wanted the format, engine, tools, and catalog to be open. I also wanted a teacher, parent, artist, or game designer to publish without first becoming a web developer.

What it does

Manse provides four interoperable layers:

  1. A browser-native engine that evaluates movement locally and keeps camera frames and inferred pose data on the playing device.
  2. A strict, versioned, data-only game-pack format. Public packs cannot execute uploaded JavaScript or escape their own asset roots.
  3. Manse Creator, an installable Codex plugin with workflows to create, generate assets, preview, validate, remix, publish, and prepare a Showcase submission.
  4. A public, link-only Showcase. Every listed game remains an independent, creator-owned Site and passes deterministic CI plus maintainer review.

The engine ships nine honest mechanics — touch, freeze, body zones, squats, pose matching, jumps, speed strikes, dance steps, and sequenced combos — each a declarative, designer-tunable pack primitive judged body-relatively (ratios of the player's own torso and joint angles, never pixels) and verified by deterministic camera-free replay fixtures. Touch games remain schemaVersion 1 packs that released engines can run; motion games declare the 0.2 contract so older runtimes reject them cleanly. New mechanics arrive through reviewed engine contributions instead of allowing executable code in untrusted packs.

How we built it

The schema, CLI validator, runtime loader, generated starter, creator plugin, catalog builder, and Showcase share one versioned contract. Generated games bundle the runtime, pose model, WebAssembly, packs, and media in their own Site, so play does not require a CDN, OpenAI API key, or runtime model call.

The engine separates pose input from rendering and challenge evaluation. That makes the deterministic simulator both the fastest judge path and the same engine path used by camera play. The Showcase builds a checked-in snapshot from reviewed public manifests; it never proxies, iframes, or executes creator code.

How Codex and GPT-5.6 were used

Codex with GPT-5.6 was the primary engineering and creator environment. It was used for product reframing, multi-package architecture, schema-constrained authoring, test generation, visual and interaction iteration, privacy review, debugging, release validation, and Sites packaging. Timestamped commits and the decision log show the major choices made during Build Week.

The same collaboration model is part of the product. Inside Manse Creator, GPT-5.6 interprets a non-developer's brief, plans safe movement and original assets, authors declarative content across multiple files, runs deterministic checks, repairs failures, and guides publishing. In short: GPT-5.6 is the factory; the browser is the product. A published game makes no GPT request at play time.

Challenges and decisions

The largest product decision was removing a central upload service, account system, and hosted game runner from v0.1. Instead, creators publish independent Sites and contribute only a manifest URL. This reduced privacy and moderation risk, made self-hosting real, and kept ownership with creators.

We also chose data-only packs over arbitrary extensions, one canonical runtime over overlapping engine packages, fixed hashes for bundled pose assets, and a simulator-first judge path. We explicitly avoid claiming universal device or recognition support before completing a measured hardware matrix.

Accomplishments

  • A fresh creator project can be generated, installed, typechecked, tested, built, and validated outside the monorepo.
  • Valid and intentionally invalid manifests and packs exercise the same public contract used by the CLI, runtime, plugin, and Showcase.
  • Pose models and WebAssembly are bundled with fixed provenance and SHA-256 verification; camera and child data are not transmitted by Manse.
  • The repository marketplace exposes seven complete creator workflows rather than demo-only instructions.
  • Six independently hosted public games demonstrate the full publish-and-list loop. Fire Hose Hero is the release-quality flagship: a three-alarm, 12-fire mission with a continuous hose, reactive targets, score/combo, wave timers, authored sound, and explicit victory/failure. The other five entries are labeled honestly as engine mechanic demos.
  • Generated games begin with an explicit fantasy, physical verb, themed target, and three escalating beats. Publication blocks until a game-specific renderer, reaction states, continuous feedback, audio, reduced-motion play, and genuine gameplay/completion evidence pass the quality contract.
  • The public judge path requires no rebuild, camera, account, or API key.

What we learned

The open ecosystem is more important than any one game. A small, strict contract plus independent hosting creates a useful boundary: creators can own and remix content, players can follow ordinary links, and the official catalog can remain curated without becoming a surveillance or execution platform.

We also learned that simulator quality is product quality. It makes authoring, CI, accessibility evaluation, and judging reliable while preserving the real camera path for play.

What's next

After v0.1, we plan to publish a measured device matrix, add reviewed reusable movement primitives, improve calibration and renderer fallback, harden catalog moderation, and invite creators to publish independent games and engine extensions. The contracts and platform remain MIT licensed and self-hostable.

Judge test path

  1. Open https://manse-showcase.ran584000.chatgpt.site without signing in.
  2. Open https://manse-showcase.ran584000.chatgpt.site/playground?provider=simulated and complete the target sequence with mouse or touch input.
  3. Follow the flagship link to https://fire-hose-hero.ran584000.chatgpt.site and verify that it is an independent Site.
  4. Inspect /.well-known/manse-game.json on that game origin.
  5. Install Manse Creator from the repository marketplace using the README steps.
  6. Review DECISIONS.md, docs/ARCHITECTURE.md, docs/PRIVACY.md, and docs/RELEASE-EVIDENCE.md for implementation and verification evidence.

No test account, API key, camera, or local build is required for steps 1–4.

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