Embeddable Game Standard: Key Functions

This section details the primary functions that a game contract must implement to comply with the Embeddable Game Standard and be compatible with Budokan tournaments.

mint

fn mint(
    ref self: ComponentState<TContractState>,
    player_name: felt252,
    settings_id: u32,
    start: Option<u64>,
    end: Option<u64>,
    to: ContractAddress,
) -> u64;

Purpose: Mint a new game token (ERC721) for a player, with associated metadata and settings.

• player_name: Name of the player (felt252).
• settings_id: ID of the game settings to use.
• start, end: Optional start and end timestamps for the game session.
• to: Address to mint the token to.

Returns: Token ID of the newly minted game token.

game_metadata

fn game_metadata(self: @ComponentState<TContractState>) -> GameMetadata;

Purpose: Retrieve metadata for the game contract (name, description, developer, etc.).

Returns: GameMetadata struct.

token_metadata

fn token_metadata(self: @ComponentState<TContractState>, token_id: u64) -> TokenMetadata;

Purpose: Retrieve metadata for a specific game token (player, settings, lifecycle, etc.).

• token_id: ID of the game token.

Returns: TokenMetadata struct.

game_count

fn game_count(self: @ComponentState<TContractState>) -> u64;

Purpose: Get the total number of games/tokens minted by the contract.

Returns: Total count (u64).

emit_metadata_update

fn emit_metadata_update(ref self: ComponentState<TContractState>, game_id: u64);

Purpose: Emit an event when token metadata is updated, for offchain indexing and UI updates.

• game_id: ID of the game token whose metadata was updated.

initializer

fn initializer(
    ref self: ComponentState<TContractState>,
    creator_address: ContractAddress,
    name: felt252,
    description: ByteArray,
    developer: felt252,
    publisher: felt252,
    genre: felt252,
    image: ByteArray,
    namespace: ByteArray,
    score_model: ByteArray,
    score_attribute: ByteArray,
    settings_model: ByteArray,
);

Purpose: Initialize the game contract with metadata, settings, and storage configuration. Mints a creator token and registers interfaces.

• creator_address: Address of the game creator.
• name, description, developer, publisher, genre, image: Metadata fields.
• namespace, score_model, score_attribute, settings_model: Storage and configuration fields.

Additional Functions

• namespace: Returns the namespace used for storage.
• score_model: Returns the score model identifier.
• score_attribute: Returns the score attribute identifier.
• settings_model: Returns the settings model identifier.
• set_settings: Set or update game settings details.
• assert_setting_exists: Ensure a settings ID exists before minting.