Token Factory

The token factory allows creating tokens using the bank module from the Cosmos SDK.

This Noria fork has upgraded dependencies to Cosmos SDK v0.47.2 and wasmvm 1.2.3.

Messages

CreateDenom

Creates a denom of factory/{creator address}/{subdenom} given the denom creator address and the subdenom. Subdenoms can contain [a-zA-Z0-9./].

message MsgCreateDenom {
  string sender = 1 [ (gogoproto.moretags) = "yaml:\"sender\"" ];
  string subdenom = 2 [ (gogoproto.moretags) = "yaml:\"subdenom\"" ];
}

State Modifications:

• Fund community pool with the denom creation fee from the creator address, set in Params.
• Set DenomMetaData via bank keeper.
• Set AuthorityMetadata for the given denom to store the admin for the created denom factory/{creator address}/{subdenom}. Admin is automatically set as the Msg sender.
• Add denom to the CreatorPrefixStore, where a state of denoms created per creator is kept.

Mint

Minting of a specific denom is only allowed for the current admin. Note, the current admin is defaulted to the creator of the denom.

message MsgMint {
  string sender = 1 [ (gogoproto.moretags) = "yaml:\"sender\"" ];
  cosmos.base.v1beta1.Coin amount = 2 [
    (gogoproto.moretags) = "yaml:\"amount\"",
    (gogoproto.nullable) = false
  ];
}

State Modifications:

• Safety check the following
  • Check that the denom minting is created via tokenfactory module
  • Check that the sender of the message is the admin of the denom
• Mint designated amount of tokens for the denom via bank module

Burn

Burning of a specific denom is only allowed for the current admin. Note, the current admin is defaulted to the creator of the denom.

message MsgBurn {
  string sender = 1 [ (gogoproto.moretags) = "yaml:\"sender\"" ];
  cosmos.base.v1beta1.Coin amount = 2 [
    (gogoproto.moretags) = "yaml:\"amount\"",
    (gogoproto.nullable) = false
  ];
}

State Modifications:

• Saftey check the following
  • Check that the denom minting is created via tokenfactory module
  • Check that the sender of the message is the admin of the denom
• Burn designated amount of tokens for the denom via bank module

ChangeAdmin

Change the admin of a denom. Note, this is only allowed to be called by the current admin of the denom.

message MsgChangeAdmin {
  string sender = 1 [ (gogoproto.moretags) = "yaml:\"sender\"" ];
  string denom = 2 [ (gogoproto.moretags) = "yaml:\"denom\"" ];
  string newAdmin = 3 [ (gogoproto.moretags) = "yaml:\"new_admin\"" ];
}

SetDenomMetadata

Setting of metadata for a specific denom is only allowed for the admin of the denom. It allows the overwriting of the denom metadata in the bank module.

message MsgChangeAdmin {
  string sender = 1 [ (gogoproto.moretags) = "yaml:\"sender\"" ];
  cosmos.bank.v1beta1.Metadata metadata = 2 [ (gogoproto.moretags) = "yaml:\"metadata\"", (gogoproto.nullable)   = false ];
}

State Modifications:

• Check that sender of the message is the admin of denom
• Modify AuthorityMetadata state entry to change the admin of the denom

Expectations from the chain

The chain's bech32 prefix for addresses can be at most 16 characters long.

This comes from denoms having a 128 byte maximum length, enforced from the SDK, and us setting longest_subdenom to be 44 bytes.

A token factory token's denom is: factory/{creator address}/{subdenom}

Splitting up into sub-components, this has:

• len(factory) = 7
• 2 * len("/") = 2
• len(longest_subdenom)
• len(creator_address) = len(bech32(longest_addr_length, chain_addr_prefix)).

Longest addr length at the moment is 32 bytes. Due to SDK error correction settings, this means len(bech32(32, chain_addr_prefix)) = len(chain_addr_prefix) + 1 + 58. Adding this all, we have a total length constraint of 128 = 7 + 2 + len(longest_subdenom) + len(longest_chain_addr_prefix) + 1 + 58. Therefore len(longest_subdenom) + len(longest_chain_addr_prefix) = 128 - (7 + 2 + 1 + 58) = 60.

The choice between how we standardized the split these 60 bytes between maxes from longest_subdenom and longest_chain_addr_prefix is somewhat arbitrary. Considerations going into this:

• Per BIP-0173 the technically longest HRP for a 32 byte address ('data field') is 31 bytes. (Comes from encode(data) = 59 bytes, and max length = 90 bytes)
• subdenom should be at least 32 bytes so hashes can go into it
• longer subdenoms are very helpful for creating human readable denoms
• chain addresses should prefer being smaller. The longest HRP in cosmos to date is 11 bytes. (persistence)

For explicitness, its currently set to len(longest_subdenom) = 44 and len(longest_chain_addr_prefix) = 16.

Please note, if the SDK increases the maximum length of a denom from 128 bytes, these caps should increase.

So please don't make code rely on these max lengths for parsing.

WASM Bindings for smart contracts

ExecuteMsgs

#[cw_serde]
/// A number of Custom messages that can call into the chain custom modules bindings
pub enum ChainMsg { // can be renamed to your chain
    Token(TokenFactoryMsg),
}


#[cw_serde]
/// A number of Custom messages that can call into the TokenFactory bindings
pub enum TokenFactoryMsg {
    /// CreateDenom creates a new factory denom, of denomination:
    /// factory/{creating contract address}/{Subdenom}
    /// Subdenom can be of length at most 44 characters, in [0-9a-zA-Z./]
    /// The (creating contract address, subdenom) pair must be unique.
    /// The created denom's admin is the creating contract address,
    /// but this admin can be changed using the ChangeAdmin binding.
    CreateDenom {
        subdenom: String,
        metadata: Option<DenomMetadata>,
    },
    /// ChangeAdmin changes the admin for a factory denom.
    /// If the NewAdminAddress is empty, the denom has no admin.
    ChangeAdmin { denom: String, new_admin: Addr },
    /// Contracts can mint native tokens for an existing factory denom
    /// that they are the admin of.
    Mint {
        denom: String,
        amount: String,
        mint_to_address: Addr,
    },
    /// Contracts can burn native tokens for an existing factory denom
    /// that they are the admin of.
    /// Currently, the burn from address must be the admin contract.
    Burn {
        denom: String,
        amount: String,
        burn_from_address: Addr,
    },
    /// Sets the metadata on a denom which the contract controls
    SetDenomMetadata { metadata: DenomMetadata },
    /// Forces a transfer of tokens from one address to another.
    ForceTransfer {
        denom: String,
        from_address: Addr,
        to_address: Addr,
        amount: String,
    },
}

/// DenomUnit is used to describe a token for the Bank module; part of the SetDenomMetadata message
#[cw_serde]
pub struct DenomUnit {
    /// Denom represents the string name of the given denom unit (e.g uatom). pub denom: String,
    pub denom: String,
    /// Exponent represents power of 10 exponent that one must
    /// raise the base_denom to in order to equal the given DenomUnit's denom
    /// 1 denom = 1^exponent base_denom
    /// (e.g. with a base_denom of uatom, one can create a DenomUnit of 'atom' with
    /// exponent = 6, thus: 1 atom = 10^6 uatom).
    pub exponent: u32,
    /// Aliases is a list of string aliases for the given denom
    pub aliases: Vec<String>,
}

/// DenomMetadata is used to describe a token for the Bank module; part of the SetDenomMetadata message
#[cw_serde]
pub struct DenomMetadata {
    pub description: String,
    /// DenomUnits represents the list of DenomUnit's for a given coin
    pub denom_units: Vec<DenomUnit>,
    /// Base represents the base denom (should be the DenomUnit with exponent = 0).
    pub base: String,
    /// Display indicates the suggested denom that should be displayed in clients.
    pub display: String,
    /// Name defines the name of the token (eg: Cosmos Atom)
    pub name: String,
    /// Symbol is the token symbol usually shown on exchanges (eg: ATOM).
    /// This can be the same as the display.
    pub symbol: String,
}

Queries

#[cw_serde]
/// A number of Custom queries that can call into the chain custom modules bindings
pub enum ChainQuery { // can be renamed to your chain
    Token(TokenFactoryQuery),
}

#[cw_serde]
/// A number of Custom queries that can call into the TokenFactory bindings
pub enum TokenFactoryQuery {
    FullDenom { subdenom: String, creator_addr: Addr },
    Admin { denom: String },
    Metadata { denom: String },
    DenomsByCreator { creator: Addr },
    Params {}
}

Query Responses

#[cw_serde]
pub FullDenomResponse struct {
	pub denom: String;
}

#[cw_serde]
pub AdminResponse struct {
	pub admin: String;
}

#[cw_serde]
pub MetadataResponse struct {
	pub metadata Option<Metadata>;
}

#[cw_serde]
pub DenomsByCreatorResponse struct {
	pub denoms Vec<String>;
}

#[cw_serde]
pub ParamsResponse struct {
	pub params TokenParams;
}

#[cw_serde]
pub struct TokenParams {
    pub denom_creation_fee: Vec<DenomCreationFee>,
}

#[cw_serde]
pub struct DenomCreationFee {
    pub amount: String,
    pub denom: String,
}