🖇️Integration 101

Common contract integration points.

You can find deployed contracts addresses and interfaces in Deployed Addresses.

View functions

Get list of all the Dens

// IndexManager.sol
struct IIndexAndStatus {
    address index;
    bool verified;
}

function allIndexes() external view returns (IIndexAndStatus[] memory);

If the Den is not verified it's better not to interact with it, as it may have been unverified for security reasons.

Get Den Info (CBR, fees)

// IndexLens.sol
struct Fees {
    uint16 burn;
    uint16 bond;
    uint16 debond;
    uint16 buy;
    uint16 sell;
}

struct DenInfoMutable {
    uint cbr;
    Fees fees;
    address[] tokens;
    address pairedToken;
    [...]
}
function getIndexImmutableInfo(address _indexAddress) external view returns (DenInfoImmutable memory info_);

Returns DenInfoImmutable struct with Den info which cannot change:

• cbr as a number with 18 decimals.

• fees struct with all the fees except partner fee (taken on top of other fees, transparent to the user)

• tokens array of underlying assets (currently Arbera supports only 1 asset Dens).

• pairedToken address of the Paired LP Token (currently HONEY or WBERA).

And many more — check out IndexLens.sol verified contract code.

Calculate CBR (Manual)

IDecentralizedIndex index = IDecentralizedIndex(_indexAddress);
uint totalSupply = index.totalSupply();
// Get underlying asset in th Den contract.
// Assuming there is only one underlying asset.
IDecentralizedIndex.IndexAssetInfo[] memory tokens = index.getAllAssets();
uint underlying = IERC20(tokens[0].token).balanceOf(_indexAddress);
uint decimals = IERC20Metadata(tokens[0].token).decimals();
// Normalize decimals
if (decimals < 18) {
	info_.underlying *= 10 ** (18 - decimals);
}
uint cbr = underlying == 0 || totalSupply == 0 ? 1e18 : (underlying * 1e18) / totalSupply;

To get CBR just divide underlying.balanceOf(index) by index.totalSupply() .

If totalSupply is 0 or there is no underlying token deposited it should default to 1e18.

Get amount of brTOKEN received by wrapping TOKEN

// IndexLens.sol
function getBondAmountsOut(address _index, address _token, uint _amount) external view returns (uint) {

• _index — address of the Den token.

• _token — underlying asset of the Den.

• _amount — amount of underlying _token to wrap.

Returns amounts of brTOKEN received (after fees and accounting for CBR).

Get amount of TOKEN received by unwrapping brTOKEN

// IndexLens.sol
function getDebondAmountsOut(
    address _index,
    uint _amount
) external view returns (address[] memory tokens_, uint[] memory amounts_)

• _index — address of the Den token.

• _amount — amount of underlying _index to unwrap.

Returns array of token addresses and array of amounts.

Currently all Dens have single asset, so it's safe to assume you only receive 1 token, ie. length of the arrays equals 1.

Interactions

Wrap TOKEN into brTOKEN

// WeightedIndex.sol
function bond(address token, uint amount, uint amountMintMin) external;

• token — underlying token address

• amount — amount to wrap.

• amountMintMin — minimum amount to receive (considdering fees and CBR).

Calling this function needs approval of the amount of token to the Den token contract.

Unwrap brTOKEN into TOKEN

// WeightedIndex.sol
function debond(uint amount, address[] memory token, uint8[] memory percentage) external;

• amount — amount to wrap.

• amountMintMin — minimum amount to receive (considering fees and CBR).

This function doesn't need approvals.

Add liquidity without fees

// WeightedIndex.sol
function addLiquidityV2(uint idxTokens, uint daiTokens, uint slippage, uint deadline) external returns (uint);

• idxTokens — amount of Den tokens (brTOKEN).

• daiTokens — amount of paired LP Token (currently DAI or WBERA).

• slippage — slippage as number with 4 decimals, ie. 100 = 1%

• deadline — deadline timestamp for providing liquidity.

Calling this function needs approval of the daiTokens of pairedLPToken (DAI or WEBERA) to the Den token contract.

Remove liquidity without fees

// WeightedIndex.sol
function removeLiquidityV2(uint lpTokens, uint minTokens, uint minDAI, uint deadline) external;

• idxTokens — amount of Den tokens (brTOKEN).

• daiTokens — amount of paired LP Token (currently DAI or WBERA).

• slippage — slippage as number with 4 decimals, ie. 100 = 1%

• deadline — deadline timestamp for providing liquidity.

Calling this function needs approval of the lpTokens of LP receipt token to the Den token contract.

Flash loan underlying tokens

/**
 * @notice Take flash loan of underlying tokens.
 * @dev Other index functions are locked during flash loan.
 * @param _recipient Recipient of the flash loan.
 * @param _token Address of the token to flash loan.
 * @param _amount Amount of the token to flash loan.
 * @param _data Data passed to recipient in the callback.
 */
function flash(address _recipient, address _token, uint _amount, bytes calldata _data) external

You need to implement IFlashLoanRecipient interface.