Harvest: interest rate model params (#719)

* add interest rate models to params

* move interest rate models to money market param

* add interest rate models to store

* update store interest rate models from params

* refactor money market init function, update tests

* use cmp package for optimized comparison

* implement equal function, remove gocmp dep

* delete unseen interest rate model param from store

go.sum

@@ -159,7 +159,6 @@ github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=
 github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=

x/harvest/abci.go

@@ -11,5 +11,6 @@ func BeginBlocker(ctx sdk.Context, k Keeper) {
 		k.ApplyDelegationRewards(ctx, k.BondDenom(ctx))
 		k.SetPreviousDelegationDistribution(ctx, ctx.BlockTime(), k.BondDenom(ctx))
 	}
+	k.ApplyInterestRateUpdates(ctx)
 	k.SetPreviousBlockTime(ctx, ctx.BlockTime())
 }

x/harvest/keeper/borrow_test.go

@@ -275,12 +275,12 @@ func (suite *KeeperTestSuite) TestBorrow() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", true, tc.args.usdxBorrowLimit, sdk.MustNewDecFromStr("1"), "usdx:usd", sdk.NewInt(USDX_CF)),
+					types.NewMoneyMarket("usdx", true, tc.args.usdxBorrowLimit, sdk.MustNewDecFromStr("1"), "usdx:usd", sdk.NewInt(USDX_CF), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("busd", false, sdk.NewDec(100000000*BUSD_CF), sdk.MustNewDecFromStr("1"), "busd:usd", sdk.NewInt(BUSD_CF)),
+					types.NewMoneyMarket("busd", false, sdk.NewDec(100000000*BUSD_CF), sdk.MustNewDecFromStr("1"), "busd:usd", sdk.NewInt(BUSD_CF), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(100000000*KAVA_CF), tc.args.loanToValueKAVA, "kava:usd", sdk.NewInt(KAVA_CF)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(100000000*KAVA_CF), tc.args.loanToValueKAVA, "kava:usd", sdk.NewInt(KAVA_CF), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("btcb", false, sdk.NewDec(100000000*BTCB_CF), tc.args.loanToValueBTCB, "btcb:usd", sdk.NewInt(BTCB_CF)),
+					types.NewMoneyMarket("btcb", false, sdk.NewDec(100000000*BTCB_CF), tc.args.loanToValueBTCB, "btcb:usd", sdk.NewInt(BTCB_CF), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("bnb", false, sdk.NewDec(100000000*BNB_CF), tc.args.loanToValueBNB, "bnb:usd", sdk.NewInt(BNB_CF)),
+					types.NewMoneyMarket("bnb", false, sdk.NewDec(100000000*BNB_CF), tc.args.loanToValueBNB, "bnb:usd", sdk.NewInt(BNB_CF), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("xyz", false, sdk.NewDec(1), tc.args.loanToValueBNB, "xyz:usd", sdk.NewInt(1)),
+					types.NewMoneyMarket("xyz", false, sdk.NewDec(1), tc.args.loanToValueBNB, "xyz:usd", sdk.NewInt(1), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), types.DefaultPreviousBlockTime, types.DefaultDistributionTimes)
 

x/harvest/keeper/claim_test.go

@@ -265,8 +265,8 @@ func (suite *KeeperTestSuite) TestClaim() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), types.DefaultPreviousBlockTime, types.DefaultDistributionTimes)
 			tApp.InitializeFromGenesisStates(authGS, app.GenesisState{types.ModuleName: types.ModuleCdc.MustMarshalJSON(harvestGS)})

x/harvest/keeper/deposit_test.go

@@ -108,8 +108,8 @@ func (suite *KeeperTestSuite) TestDeposit() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), types.DefaultPreviousBlockTime, types.DefaultDistributionTimes)
 			tApp.InitializeFromGenesisStates(authGS, app.GenesisState{types.ModuleName: types.ModuleCdc.MustMarshalJSON(harvestGS)})
@@ -251,8 +251,8 @@ func (suite *KeeperTestSuite) TestWithdraw() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), types.DefaultPreviousBlockTime, types.DefaultDistributionTimes)
 			tApp.InitializeFromGenesisStates(authGS, app.GenesisState{types.ModuleName: types.ModuleCdc.MustMarshalJSON(harvestGS)})

x/harvest/keeper/interest.go

@@ -0,0 +1,31 @@
+package keeper
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/kava-labs/kava/x/harvest/types"
+)
+
+// ApplyInterestRateUpdates translates the current interest rate models from the params to the store
+func (k Keeper) ApplyInterestRateUpdates(ctx sdk.Context) {
+	denomSet := map[string]bool{}
+
+	params := k.GetParams(ctx)
+	for _, mm := range params.MoneyMarkets {
+		model, found := k.GetInterestRateModel(ctx, mm.Denom)
+		if !found {
+			k.SetInterestRateModel(ctx, mm.Denom, mm.InterestRateModel)
+			continue
+		}
+		if !model.Equal(mm.InterestRateModel) {
+			k.SetInterestRateModel(ctx, mm.Denom, mm.InterestRateModel)
+		}
+		denomSet[mm.Denom] = true
+	}
+
+	k.IterateInterestRateModels(ctx, func(denom string, i types.InterestRateModel) bool {
+		if !denomSet[denom] {
+			k.DeleteInterestRateModel(ctx, denom)
+		}
+		return false
+	})
+}

x/harvest/keeper/keeper.go

@@ -255,3 +255,43 @@ func (k Keeper) GetBorrowedCoins(ctx sdk.Context) (sdk.Coins, bool) {
 	k.cdc.MustUnmarshalBinaryBare(bz, &borrowedCoins)
 	return borrowedCoins, true
 }
+
+// GetInterestRateModel returns an interest rate model from the store for a denom
+func (k Keeper) GetInterestRateModel(ctx sdk.Context, denom string) (types.InterestRateModel, bool) {
+	store := prefix.NewStore(ctx.KVStore(k.key), types.InterestRateModelsPrefix)
+	bz := store.Get([]byte(denom))
+	if bz == nil {
+		return types.InterestRateModel{}, false
+	}
+	var interestRateModel types.InterestRateModel
+	k.cdc.MustUnmarshalBinaryBare(bz, &interestRateModel)
+	return interestRateModel, true
+}
+
+// SetInterestRateModel sets an interest rate model in the store for a denom
+func (k Keeper) SetInterestRateModel(ctx sdk.Context, denom string, interestRateModel types.InterestRateModel) {
+	store := prefix.NewStore(ctx.KVStore(k.key), types.InterestRateModelsPrefix)
+	bz := k.cdc.MustMarshalBinaryBare(interestRateModel)
+	store.Set([]byte(denom), bz)
+}
+
+// DeleteInterestRateModel deletes an interest rate model from the store
+func (k Keeper) DeleteInterestRateModel(ctx sdk.Context, denom string) {
+	store := prefix.NewStore(ctx.KVStore(k.key), types.InterestRateModelsPrefix)
+	store.Delete([]byte(denom))
+}
+
+// IterateInterestRateModels iterates over all interest rate model objects in the store and performs a callback function
+// 		that returns both the interest rate model value and the key it's stored under
+func (k Keeper) IterateInterestRateModels(ctx sdk.Context, cb func(denom string, interestRateModel types.InterestRateModel) (stop bool)) {
+	store := prefix.NewStore(ctx.KVStore(k.key), types.InterestRateModelsPrefix)
+	iterator := sdk.KVStorePrefixIterator(store, []byte{})
+	defer iterator.Close()
+	for ; iterator.Valid(); iterator.Next() {
+		var interestRateModel types.InterestRateModel
+		k.cdc.MustUnmarshalBinaryBare(iterator.Value(), &interestRateModel)
+		if cb(string(iterator.Key()), interestRateModel) {
+			break
+		}
+	}
+}

x/harvest/keeper/keeper_test.go

@@ -1,6 +1,7 @@
 package keeper_test
 
 import (
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/suite"
@@ -153,6 +154,51 @@ func (suite *KeeperTestSuite) TestGetSetDeleteClaim() {
 	suite.Require().False(f)
 }
 
+func (suite *KeeperTestSuite) TestGetSetDeleteInterestRateModel() {
+	denom := "test"
+	model := types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))
+
+	_, f := suite.keeper.GetInterestRateModel(suite.ctx, denom)
+	suite.Require().False(f)
+
+	suite.keeper.SetInterestRateModel(suite.ctx, denom, model)
+
+	testInterestRateModel, f := suite.keeper.GetInterestRateModel(suite.ctx, denom)
+	suite.Require().True(f)
+	suite.Require().Equal(model, testInterestRateModel)
+
+	suite.Require().NotPanics(func() { suite.keeper.DeleteInterestRateModel(suite.ctx, denom) })
+
+	_, f = suite.keeper.GetInterestRateModel(suite.ctx, denom)
+	suite.Require().False(f)
+
+}
+
+func (suite *KeeperTestSuite) TestIterateInterestRateModels() {
+	testDenom := "test"
+	var setModels types.InterestRateModels
+	var setDenoms []string
+	for i := 0; i < 5; i++ {
+		denom := testDenom + strconv.Itoa(i)
+		model := types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))
+		suite.Require().NotPanics(func() { suite.keeper.SetInterestRateModel(suite.ctx, denom, model) })
+		// Save the denom and model
+		setDenoms = append(setDenoms, denom)
+		setModels = append(setModels, model)
+	}
+
+	var seenModels types.InterestRateModels
+	var seenDenoms []string
+	suite.keeper.IterateInterestRateModels(suite.ctx, func(denom string, i types.InterestRateModel) bool {
+		seenDenoms = append(seenDenoms, denom)
+		seenModels = append(seenModels, i)
+		return false
+	})
+
+	suite.Require().Equal(setModels, seenModels)
+	suite.Require().Equal(setDenoms, seenDenoms)
+}
+
 func (suite *KeeperTestSuite) getAccount(addr sdk.AccAddress) authexported.Account {
 	ak := suite.app.GetAccountKeeper()
 	return ak.GetAccount(suite.ctx, addr)

x/harvest/keeper/rewards_test.go

@@ -75,8 +75,8 @@ func (suite *KeeperTestSuite) TestApplyDepositRewards() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), tc.args.previousBlockTime, types.DefaultDistributionTimes)
 			tApp.InitializeFromGenesisStates(app.GenesisState{types.ModuleName: types.ModuleCdc.MustMarshalJSON(harvestGS)})
@@ -443,8 +443,8 @@ func harvestGenesisState(rewardRate sdk.Coin) app.GenesisState {
 				),
 			},
 			types.MoneyMarkets{
-				types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+				types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-				types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+				types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 			},
 		),
 		types.DefaultPreviousBlockTime,

x/harvest/keeper/timelock_test.go

@@ -291,8 +291,8 @@ func (suite *KeeperTestSuite) TestSendTimeLockedCoinsToAccount() {
 				),
 				},
 				types.MoneyMarkets{
-					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("usdx", false, sdk.NewDec(1000000000000000), loanToValue, "usdx:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
-					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000)),
+					types.NewMoneyMarket("ukava", false, sdk.NewDec(1000000000000000), loanToValue, "kava:usd", sdk.NewInt(1000000), types.NewInterestRateModel(sdk.MustNewDecFromStr("0.05"), sdk.MustNewDecFromStr("2"), sdk.MustNewDecFromStr("0.8"), sdk.MustNewDecFromStr("10"))),
 				},
 			), types.DefaultPreviousBlockTime, types.DefaultDistributionTimes)
 			tApp.InitializeFromGenesisStates(authGS, app.GenesisState{types.ModuleName: types.ModuleCdc.MustMarshalJSON(harvestGS)})

x/harvest/types/keys.go

@@ -37,6 +37,7 @@ var (
 	ClaimsKeyPrefix                   = []byte{0x04}
 	BorrowsKeyPrefix                  = []byte{0x05}
 	BorrowedCoinsPrefix               = []byte{0x06}
+	InterestRateModelsPrefix          = []byte{0x07}
 	sep                               = []byte(":")
 )
 

x/harvest/types/params.go

@@ -253,20 +253,22 @@ func (bl BorrowLimit) Validate() error {
 
 // MoneyMarket is a money market for an individual asset
 type MoneyMarket struct {
-	Denom            string      `json:"denom" yaml:"denom"`
+	Denom             string            `json:"denom" yaml:"denom"`
-	BorrowLimit      BorrowLimit `json:"borrow_limit" yaml:"borrow_limit"`
+	BorrowLimit       BorrowLimit       `json:"borrow_limit" yaml:"borrow_limit"`
-	SpotMarketID     string      `json:"spot_market_id" yaml:"spot_market_id"`
+	SpotMarketID      string            `json:"spot_market_id" yaml:"spot_market_id"`
-	ConversionFactor sdk.Int     `json:"conversion_factor" yaml:"conversion_factor"`
+	ConversionFactor  sdk.Int           `json:"conversion_factor" yaml:"conversion_factor"`
+	InterestRateModel InterestRateModel `json:"interest_rate_model" yaml:"interest_rate_model"`
 }
 
 // NewMoneyMarket returns a new MoneyMarket
 func NewMoneyMarket(denom string, hasMaxLimit bool, maximumLimit, loanToValue sdk.Dec,
-	spotMarketID string, conversionFactor sdk.Int) MoneyMarket {
+	spotMarketID string, conversionFactor sdk.Int, interestRateModel InterestRateModel) MoneyMarket {
 	return MoneyMarket{
-		Denom:            denom,
+		Denom:             denom,
-		BorrowLimit:      NewBorrowLimit(hasMaxLimit, maximumLimit, loanToValue),
+		BorrowLimit:       NewBorrowLimit(hasMaxLimit, maximumLimit, loanToValue),
-		SpotMarketID:     spotMarketID,
+		SpotMarketID:      spotMarketID,
-		ConversionFactor: conversionFactor,
+		ConversionFactor:  conversionFactor,
+		InterestRateModel: interestRateModel,
 	}
 }
 
@@ -279,6 +281,10 @@ func (mm MoneyMarket) Validate() error {
 	if err := mm.BorrowLimit.Validate(); err != nil {
 		return err
 	}
+
+	if err := mm.InterestRateModel.Validate(); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -295,6 +301,65 @@ func (mms MoneyMarkets) Validate() error {
 	return nil
 }
 
+// InterestRateModel contains information about an asset's interest rate
+type InterestRateModel struct {
+	BaseRateAPY    sdk.Dec `json:"base_rate_apy" yaml:"base_rate_apy"`
+	BaseMultiplier sdk.Dec `json:"base_multiplier" yaml:"base_multiplier"`
+	Kink           sdk.Dec `json:"kink" yaml:"kink"`
+	JumpMultiplier sdk.Dec `json:"jump_multiplier" yaml:"jump_multiplier"`
+}
+
+// NewInterestRateModel returns a new InterestRateModel
+func NewInterestRateModel(baseRateAPY, baseMultiplier, kink, jumpMultiplier sdk.Dec) InterestRateModel {
+	return InterestRateModel{
+		BaseRateAPY:    baseRateAPY,
+		BaseMultiplier: baseMultiplier,
+		Kink:           kink,
+		JumpMultiplier: jumpMultiplier,
+	}
+}
+
+// Validate InterestRateModel param
+func (irm InterestRateModel) Validate() error {
+	if irm.BaseRateAPY.IsNegative() || irm.BaseRateAPY.GT(sdk.OneDec()) {
+		return fmt.Errorf("Base rate APY must be between 0.0-1.0")
+	}
+
+	if irm.BaseMultiplier.IsNegative() {
+		return fmt.Errorf("Base multiplier must be positive")
+	}
+
+	if irm.Kink.IsNegative() || irm.Kink.GT(sdk.OneDec()) {
+		return fmt.Errorf("Kink must be between 0.0-1.0")
+	}
+
+	if irm.JumpMultiplier.IsNegative() {
+		return fmt.Errorf("Jump multiplier must be positive")
+	}
+
+	return nil
+}
+
+// Equal returns a boolean indicating if an InterestRateModel is equal to another InterestRateModel
+func (irm InterestRateModel) Equal(comparisonIRM InterestRateModel) bool {
+	if !irm.BaseRateAPY.Equal(comparisonIRM.BaseRateAPY) {
+		return false
+	}
+	if !irm.BaseMultiplier.Equal(comparisonIRM.BaseMultiplier) {
+		return false
+	}
+	if !irm.Kink.Equal(comparisonIRM.Kink) {
+		return false
+	}
+	if !irm.JumpMultiplier.Equal(comparisonIRM.JumpMultiplier) {
+		return false
+	}
+	return true
+}
+
+// InterestRateModels slice of InterestRateModel
+type InterestRateModels []InterestRateModel
+
 // NewParams returns a new params object
 func NewParams(active bool, lps DistributionSchedules, dds DelegatorDistributionSchedules, moneyMarkets MoneyMarkets) Params {
 	return Params{