Interactions

The SelfPeggingAsset contract exposes the primary trading and liquidity management functions for interacting with Tapio pools. This section details the available functions for minting SPAs, executing swaps, and redeeming assets, along with their parameters and return values for integration into trading interfaces and DeFi applications.

User Operations

mint

Adds liquidity to the pool by depositing tokens in the amounts specified in _amounts. Returns the amount of SPA tokens minted, which must be at least _minMintAmount.

function mint(uint256[] calldata _amounts, uint256 _minMintAmount) external returns (uint256);

Parameters

Name	Type	Description
_amounts	uint256[]	Unconverted token balances used to mint pool token
_minMintAmount	uint256	Minimum amount of pool token to mint

Returns

Name	Type	Description
<none>	uint256	The amount of pool tokens minted

swap

Exchange between two underlying tokens.

function swap(uint256 _i, uint256 _j, uint256 _dx, uint256 _minDy) external returns (uint256);

Parameters

Name	Type	Description
_i	uint256	Token index to swap in
_j	uint256	Token index to swap out
_dx	uint256	Unconverted amount of token _i to swap in
_minDy	uint256	Minimum token _j to swap out in converted balance

Returns

Name	Type	Description
<none>	uint256	Amount of swap out

redeemProportion

Redeems pool token to underlying tokens proportionally.

function redeemProportion(uint256 _amount, uint256[] calldata _minRedeemAmounts) external returns (uint256[] memory);

Parameters

Name	Type	Description
_amount	uint256	Amount of pool token to redeem
_minRedeemAmounts	uint256[]	Minimum amount of underlying tokens to get

Returns

Name	Type	Description
<none>	uint256[]	An array of the amounts of each token to redeem

redeemSingle

Redeem pool token to one specific underlying token.

function redeemSingle(uint256 _amount, uint256 _i, uint256 _minRedeemAmount) external returns (uint256);

Parameters

Name	Type	Description
_amount	uint256	Amount of pool token to redeem
_i	uint256	Index of the token to redeem to
_minRedeemAmount	uint256	Minimum amount of the underlying token to redeem to

Returns

Name	Type	Description
<none>	uint256	Amount received

redeemMulti

Redeems underlying tokens.

function redeemMulti(uint256[] calldata _amounts, uint256 _maxRedeemAmount) external returns (uint256[] memory);

Parameters

Name	Type	Description
_amounts	uint256[]	Amounts of underlying tokens to redeem to
_maxRedeemAmount	uint256	Maximum of pool token to redeem

Returns

Name	Type	Description
<none>	uint256[]	Amounts received

Governance Functions

pause

Pause mint/swap/redeem actions.

function pause() external;

Access: only Owner (via Keeper)

unpause

Unpause mint/swap/redeem actions.

function unpause() external;

Access: only Owner (via Keeper)

setMintFee

Updates the mint fee on pool.

function setMintFee(uint256 _mintFee) external;

Parameters

Name	Type	Description
_mintFee	uint256	The new mint fee value. Uses 10 decimal precision (denominator = 10^10). Examples: 1e6 = 0.01%, 1e7 = 0.1%, 1e8 = 1%

Access: only Owner (via Keeper)

setSwapFee

Updates the swap fee on pool.

function setSwapFee(uint256 _swapFee) external;

Parameters

Name	Type	Description
_swapFee	uint256	The new swap fee value. Uses 10 decimal precision (denominator = 10^10). Examples: 1e6 = 0.01%, 1e7 = 0.1%, 1e8 = 1%

Access: only Owner (via Keeper)

setRedeemFee

Updates the redeem fee on pool.

function setRedeemFee(uint256 _redeemFee) external;

Parameters

Name	Type	Description
_redeemFee	uint256	The new redeem fee value. Uses 10 decimal precision (denominator = 10^10). Examples: 1e6 = 0.01%, 1e7 = 0.1%, 1e8 = 1%

Access: only Owner (via Keeper)

setOffPegFeeMultiplier

Updates the off peg fee multiplier of pool.

function setOffPegFeeMultiplier(uint256 _offPegFeeMultiplier) external;

Parameters

Name	Type	Description
_offPegFeeMultiplier	uint256	The new off peg fee multiplier value

Access: only Owner (via Keeper)

setExchangeRateFeeFactor

Updates the exchange rate fee factor of pool.

function setExchangeRateFeeFactor(uint256 _exchangeRateFeeFactor) external;

Parameters

Name	Type	Description
_exchangeRateFeeFactor	uint256	The new exchange rate fee factor value

Access: only Owner (via Keeper)

setDecayPeriod

Updates the decay period

function setDecayPeriod(uint256 _decayPeriod) external;

Parameters

Name	Type	Description
_decayPeriod	uint256	The new decay period value

Access: only Owner (via Keeper)

setRateChangeSkipPeriod

Updates the rate change skip period of pool.

function setRateChangeSkipPeriod(uint256 _rateChangeSkipPeriod) external;

Parameters

Name	Type	Description
_rateChangeSkipPeriod	uint256	The new rate change skip period value

Access: only Owner (via Keeper)

updateFeeErrorMargin

Updates the fee error margin of pool.

function updateFeeErrorMargin(uint256 newValue) external;

Parameters

Name	Type	Description
newValue	uint256	The new fee error margin value

Access: only Owner (via Keeper)

updateYieldErrorMargin

Updates yield error margin of pool.

function updateYieldErrorMargin(uint256 newValue) external;

Parameters

Name	Type	Description
newValue	uint256	The new yield error margin value

Access: only Owner (via Keeper)

distributeLoss

Distribute losses by rebasing negatively

function distributeLoss() external;

Access: only Owner (via Keeper)

View Functions

getSwapAmount

Computes the output amount after the swap.

function getSwapAmount(uint256 _i, uint256 _j, uint256 _dx) external view returns (uint256, uint256);

Parameters

Name	Type	Description
_i	uint256	Token index to swap in
_j	uint256	Token index to swap out
_dx	uint256	Unconverted amount of token _i to swap in

Returns

Name	Type	Description
<none>	uint256	Unconverted amount of token _j to swap out
<none>	uint256	The amount of fees charged

getMintAmount

Compute the amount of pool token that can be minted.

function getMintAmount(uint256[] calldata _amounts) external view returns (uint256, uint256);

Parameters

Name	Type	Description
_amounts	uint256[]	Unconverted token balances

Returns

Name	Type	Description
<none>	uint256	The amount of pool tokens to be minted
<none>	uint256	The amount of fees charged

getCurrentA

Get the current A value from the controller if set, or use the local value.

function getCurrentA() external view returns (uint256);

Returns

Name	Type	Description
<none>	uint256	The current A value

getTokens

Returns the array of token addresses in the pool.

function getTokens() external view returns (address[] memory);

Returns

Name	Type	Description
<none>	address[]	Array of token addresses in the pool

getRedeemProportionAmount

Computes the amounts of underlying tokens when redeeming pool token.

function getRedeemProportionAmount(uint256 _amount) external view returns (uint256[] memory, uint256);

Parameters

Name	Type	Description
_amount	uint256	Amount of pool tokens to redeem

Returns

Name	Type	Description
<none>	uint256[]	An array of the amounts of each token to redeem
<none>	uint256	The amount of fee charged

getRedeemSingleAmount

Computes the amount when redeeming pool token to one specific underlying token.

function getRedeemSingleAmount(uint256 _amount, uint256 _i) external view returns (uint256, uint256);

Parameters

Name	Type	Description
_amount	uint256	Amount of pool token to redeem
_i	uint256	Index of the underlying token to redeem to

Returns

Name	Type	Description
<none>	uint256	The amount of single token that will be redeemed
<none>	uint256	The amount of pool token charged for redemption fee

getRedeemMultiAmount

Compute the amount of pool token that needs to be redeemed.

function getRedeemMultiAmount(uint256[] calldata _amounts) external view returns (uint256, uint256);

Parameters

Name	Type	Description
_amounts	uint256[]	Unconverted token balances

Returns

Name	Type	Description
<none>	uint256	The amount of pool token that needs to be redeemed
<none>	uint256	The amount of pool token charged for redemption fee