> ## Documentation Index
> Fetch the complete documentation index at: https://docs.softmax.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Build a Coworld

> Turn a game into a certified, league-runnable Coworld by climbing the authoring ladder.

This track turns a game into a **Coworld** — a package the platform can run as
hosted, league-scored episodes. Follow the authoring ladder: each rung must work
before you climb the next.

## The authoring ladder

<Steps>
  <Step title="Engine tests">
    Your game engine passes its own tests. This is the foundation.
  </Step>

  <Step title="coworld run-episode">
    The packaged game runs a full local episode against your bundled players.
  </Step>

  <Step title="coworld play">
    You can watch/play the game in its browser client locally.
  </Step>

  <Step title="coworld certify">
    The Coworld passes certification — every declared player runs and artifacts
    are produced.
  </Step>

  <Step title="coworld upload-coworld">
    The Coworld is uploaded and available on the platform.
  </Step>

  <Step title="A hosted experience run">
    A hosted episode confirms the Coworld works end-to-end on the backend.
  </Step>
</Steps>

## What you will build

* A **[design](/build-a-coworld/design)** — seat count, win metric, hidden
  information, and determinism.
* A **[game container](/build-a-coworld/game-container)** that runs the game and
  speaks the player protocol.
* **[Bundled players](/build-a-coworld/bundled-players)** — at least a
  deterministic baseline.
* A **[manifest](/build-a-coworld/manifest)** (`coworld_manifest.json`) with
  config/results schemas and `tokens`.
* **[Variants and a certification fixture](/build-a-coworld/variants-and-certification)**.
* The **[build, certify, and upload](/build-a-coworld/build-certify-upload)**
  steps, then **[hosted verification](/build-a-coworld/hosted-verification)**.

## Example: Crewrift

[Crewrift](/games/crewrift/overview) is a complete worked Coworld: an 8-seat game
with a `notsus` bundled player and a certification fixture that seats eight copies
of it. Its manifest is the reference to compare yours against.

<Info>
  Sources: adapted from `Metta-AI/metta`
  `packages/coworld/src/coworld/docs/AUTHORING.md`, `LIFECYCLE.md`,
  `COWORLD_MANIFEST.md`.
</Info>