Mint

The mint module is in charge of the creation of new XPLA through minting. At the beginning of every block, new XPLA is released by the mint module and sent to the fee collector account to be distributed to stakers as rewards.

The current inflation rate is set to a fixed 0% annual inflation.

Concepts #

The Minting Mechanism #

The minting mechanism was designed to:

• allow for a flexible inflation rate determined by market demand targeting a particular bonded-stake ratio
• effect a balance between market liquidity and staked supply

In order to best determine the appropriate market rate for inflation rewards, a moving change rate is used. The moving change rate mechanism ensures that if the % bonded is either over or under the goal %-bonded, the inflation rate will adjust to further incentivize or disincentivize being bonded, respectively. Setting the goal %-bonded at less than 100% encourages the network to maintain some non-staked tokens which should help provide some liquidity.

It can be broken down in the following way:

• If the inflation rate is below the goal %-bonded the inflation rate will increase until a maximum value is reached
• If the goal % bonded (67% in Cosmos-Hub) is maintained, then the inflation rate will stay constant
• If the inflation rate is above the goal %-bonded the inflation rate will decrease until a minimum value is reached

Parameters #

The subspace for the Mint module is mint.

// Params holds parameters for the mint module.
type Params struct {
	// type of coin to mint
	MintDenom string `protobuf:"bytes,1,opt,name=mint_denom,json=mintDenom,proto3" json:"mint_denom,omitempty"`
	// maximum annual change in inflation rate
	InflationRateChange github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,2,opt,name=inflation_rate_change,json=inflationRateChange,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"inflation_rate_change" yaml:"inflation_rate_change"`
	// maximum inflation rate
	InflationMax github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,3,opt,name=inflation_max,json=inflationMax,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"inflation_max" yaml:"inflation_max"`
	// minimum inflation rate
	InflationMin github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,4,opt,name=inflation_min,json=inflationMin,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"inflation_min" yaml:"inflation_min"`
	// goal of percent bonded atoms
	GoalBonded github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,5,opt,name=goal_bonded,json=goalBonded,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"goal_bonded" yaml:"goal_bonded"`
	// expected blocks per year
	BlocksPerYear uint64 `protobuf:"varint,6,opt,name=blocks_per_year,json=blocksPerYear,proto3" json:"blocks_per_year,omitempty" yaml:"blocks_per_year"`
}