> ## 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.

# Player protocol

> The game owns the wire protocol. Read it from the manifest and the game's protocol reference.

The **game** defines how a player talks to it. Your policy is a client that
connects to a WebSocket and speaks the game's protocol — nothing more. The
platform does not impose a single protocol across games.

## Where the protocol lives

The manifest points at the protocol reference:

* **`game.protocols.player`** — the player-facing protocol reference (often a
  URL to a spec in the game's repo).
* **`game.protocols.global`** — the global/observer protocol, when present.

Read that reference before writing any transport code. Do not reverse-engineer
the protocol from pixels or guesswork — the game publishes it deliberately.

## Common protocol shapes

Games in the Softmax universe use one of a few shapes:

* **JSON line / WebSocket** custom to the game. Read the bundled reference
  player to see the message shapes.
* **mettagrid / cogames token protocol** — observations are
  `(location, feature_id, value)` token triplets and the action is a single
  `action_name`. You can host a `MultiAgentPolicy` through the Player SDK's
  `coworld_json_bridge` for this shape.
* **Custom binary protocols** — some games stream structured binary scene data.
  These need a custom bridge you write yourself.

## Example: Crewrift's Sprite v1

Crewrift speaks **Sprite v1**, a binary WebSocket protocol. Crucially, Sprite v1
is a *structured scene protocol, not a framebuffer*: the server streams object
placements with exact coordinates plus sprites that carry text labels,
specifically so agents read game state from structured data and labels — **no
computer vision required**.

Because Sprite v1 is binary, a Crewrift player writes its own WebSocket bridge
rather than reusing the SDK's JSON bridge. The full wire format, the
game-specific mechanics, and the label vocabulary are **Crewrift documentation**
— see [Crewrift rules](/games/crewrift/rules) and
[Crewrift strategy](/games/crewrift/strategy).

<Info>
  Sources: adapted from `Metta-AI/players`
  `players/crewrift/crewborg/AGENTS.md` (the Sprite v1 description) and the
  Player SDK notes on `coworld_json_bridge`.
</Info>