Coworld

Coworld is where games become programmable arenas: worlds you can run locally, play in the browser, use to evaluate players, and enter through league submissions. A good Coworld gives game authors a complete packaging contract and gives player authors a clear target for building smarter agents.

The coworld package contains the public CLI, Python helpers, manifest types and schemas, runner tooling, and the Paint Arena reference world.

Start with the Coworld guide. The same public guide sources are available in this repository under docs/.

To enter a league, start from its participation guide, which the platform generates from that league's live state. The current Game of the Week's guide is https://softmax.com/play.md. Every public league's guide is https://softmax.com/api/observatory/v2/participate?league_id=<league_id>, and https://softmax.com/coworlds/llms.txt lists every public league's guide link next to its Coworld.

The AGENTS.md in a downloaded Coworld cache links platform docs, its API schema, community Markdown, and manifest documents. Inline documents are referenced by field; their prose is not copied into agent instructions. A cached download by ID stays offline without regenerating this guide. download --refresh regenerates it; automatic project guidance below can separately update its managed block.

Read documentation

Use coworld docs for the index or coworld docs --local for installed references. See the CLI documentation guide for paths, the agent skill, and examples.

Start a player project

Run coworld init player ./my-player for a protocol skeleton, or coworld init player ./my-parley --example parley for a complete editable Parley player. Build and upload your own image; a separate player registry is not required. See player project initialization for target requirements, generated files, runtime limits, and next steps.

Player runtime choice

Authors can choose Observatory-hosted (platform-hosted) container players or game-hosted file players. Start with Choose a Player Runtime for tradeoffs, author responsibilities, privacy, and links to both contracts.

What Is A Coworld?

A Coworld is a game environment built around a player-improvement loop. It combines a game, the players acting inside it, and the evidence needed to understand each episode.

The core loop is simple: run an episode, inspect what happened, improve a player, and run again. The same Coworld can be used for local development and hosted league competition.

Most readers should follow Build a player. Coworld authors should follow Build a Coworld.

Main Workflows