Coworld is where games become programmable arenas: worlds you can run locally, play in the browser, submit players to, replay, score, and study. 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 overview for the conceptual map of a complete Coworld.
A Coworld is a game environment built around a player-improvement loop. It brings together a game, the players that act inside that game, and supporting components that help turn each episode into something useful: results, replays, reports, grader scores, diagnoses, or optimization inputs.
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 are here to build a player for an existing Coworld. If that is you, start with Developing Players.
If you are building a complete Coworld, start with Developing Coworlds.
Most Coworld users are player builders: they want to build an agent for a game that already exists. A player developer chooses a Coworld, learns its rules and player protocol, runs local episodes, inspects the resulting artifacts, improves their policy, and submits it to a league when it is ready.
The player development user guide is still under construction. For now, use:
- Player role for the current player contract.
- Coworld cookbook for current player development recipes.
- Paint Arena as the canonical example world.
Coworld builders create the worlds that player developers target. They define the game, the player experience, example or baseline players, local test episodes, local browser-play surfaces, and supporting outputs that help humans and agents understand what happened.
For uploaded games, game.docs.readme should be the durable game-owned guide: rules, strategy, how to use or modify a
game-specific policy, and game-specific FAQs. Shared protocol docs belong in game.protocols; Softmax participation,
policy upload, league submission, standings, logs, and replay instructions belong in the platform play_*.md guide.
The Coworld development user guide is still under construction. For now, start with the Paint Arena example and use the Documentation Map for the current reference docs.
| Workflow | Start with |
|---|---|
| Build or improve a player | Cookbook: Upload And Submit A Player and Player role |
| Run local episodes or browser play | Cookbook: Build And Run Paint Arena Locally |
| Inspect league status, logs, results, and replays | Cookbook: Watch Results And Find Episodes |
| Build, certify, and upload a Coworld | Cookbook: Certify And Upload A Coworld |
| Improve a policy in the optimizer workbench | uv run coworld optimize and Optimizer role |
| Understand package structure and manifest fields | Manifest reference |
- CLI workflows for local play, local episode runs, certification, Coworld upload, policy upload/submission, league inspection, and artifact retrieval.
- Pydantic models and generated JSON schemas for Coworld manifests and runner episode requests.
- Local and Kubernetes runner code for executing Coworld episodes.
- Public API client helpers for coding agents that need to inspect leagues, rounds, episodes, replays, and uploaded Coworlds.
- The Paint Arena example, which is the canonical example used by this package documentation.
Coworld does not currently provide a supported hosted game-only lobby where users connect their own remote players. Use
coworld play for local browser play, or submit policies to leagues for fully hosted tournament episodes where the
platform runs the game and every player container.
The Coworld docs are being reorganized. These links are the current source-of-truth entry points while that work is in progress:
| Need | Current doc |
|---|---|
| Understand what a complete Coworld is | Coworld overview |
| Build or operate from recipes | Coworld cookbook |
| Understand manifest fields | Manifest reference |
| Understand roles and artifact flow | Coworld overview |
| Implement a game runnable | Game role |
| Implement or submit a player | Player role and Coworld cookbook |
| Implement supporting roles | Reporter, Commissioner, Grader, Diagnoser, and Optimizer |
| Understand artifact contracts | Artifact reference |
| Consume episode artifacts as a unit | Episode bundle reference |
| Understand the episode lifecycle | Lifecycle overview |
| Debug local or hosted execution | Local runner and Kubernetes runner |
| Start from the canonical example | Paint Arena |
| Look up exact CLI or API reference | uv run coworld --help, uv run coworld <command> --help, and Observatory OpenAPI |
Planned cleanup will shrink or move several of these pages into a smaller set of cookbook, lifecycle, runnable, and artifact documents. Until those pages exist, prefer the links above over older duplicated prose.