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Fungible Tokens

Sui provides two standards for creating fungible tokens. Both produce Coin<T> objects that are fully interoperable with wallets, DeFi protocols, and address balances. The difference is in how you create, configure, and manage the token's metadata and supply.

Coin standard vs currency standard​

FeatureCoin StandardCurrency Standard
Creation functioncoin::create_currencycoin_registry::new_currency or new_currency_with_otw
Metadata storageStandalone CoinMetadata objectCentralized in CoinRegistry at 0xc
Supply modelsUncontrolled onlyFixed, burn-only, or uncontrolled
Regulatory supportcreate_regulated_currency_v2make_regulated() during initialization
Metadata updatesRequires TreasuryCapDedicated MetadataCap (can be frozen or deleted)
RPC discoveryRequires knowing CoinMetadata object IDQueryable from the central registry
StatusActiveRecommended for new projects

Choosing a standard​

Use the following guidance to pick the right standard for your project:

Recommended: Currency Standard

For new tokens, use the Currency Standard. It provides richer supply controls, centralized metadata discovery, and a dedicated MetadataCap for metadata management.

Creating a new token​

  • Most projects: Use coin_registry::new_currency. You can call this at any time after publishing your package. See Create Fungible Tokens: Currency Standard.

  • Need a One-Time Witness proof: Use coin_registry::new_currency_with_otw in your module's init function. This requires a two-step publish-then-finalize process.

  • Need the legacy Coin Standard: Use coin::create_currency in your module's init function. See Create Fungible Tokens: Coin Standard.

Configuring supply​

Only the Currency Standard supports supply model configuration:

  • Fixed supply: Mint the total supply during initialization, then call make_supply_fixed to lock the TreasuryCap inside the Currency. No further minting or burning is possible.
  • Burn-only (deflationary): Mint the initial supply, then call make_supply_burn_only to prevent future minting while still allowing burns.
  • Uncontrolled: The default. The TreasuryCap holder can mint and burn freely.

Adding regulatory controls​

Both standards support regulated tokens with deny-list capabilities. The Currency Standard simplifies this with make_regulated(allow_global_pause, ctx) during initialization, which returns a DenyCapV2 for managing the deny list. See Regulated Tokens for deny-list management.

Migrating an existing token​

If you have an existing Coin Standard token, the Currency Standard provides migration functions to register your coin in the CoinRegistry while preserving its existing CoinMetadata object ID. See the Currency Standard reference for migration details.

Example patterns​

These guides show common token configurations in action: