borrow

params of yAssetParams -> (list(op), storage upd)

Take a loan from protocol. Accepts amount of wanted token and it's related yToken's tokenId.

Borrowing new market could fail if user already borrowed from maxMarkets of other markets.

The yToken contract expects that underlying token info of tokenId and all borrowed by user before tokenIds are updated by calling PriceFeed.getPrice and updateInterest in the same block before this contract method

Types

type yAssetParams       is [@layout:comb] record [
  tokenId                 : nat; // yToken token Id
  amount                  : nat; // amount tokens to borrow
]

Parameter	Type	Description
tokenId	nat	yToken identifier
amount	nat	amount of underlying tokens to be borrowed from protocol

Usage

🌮 Taquito

const borrowTokenId = 0; // or new BigNumber(0) or "0"
const amount = 10_000_000; // amount of borrow tokens.
const yupana = await tezos.contract.at(yTokenAddress);
const proxy = await tezos.contract.at(proxyAddress);
const borrowedTokenIds = [1, 2]; // user borrowed tokens
const updBorrowed = borrowedTokenIds.reduce(
  (batch, tokenId) => {
    batch.push({
        kind: "transaction",
        ...yupana.methods.updateInterest(tokenId).toTransferParams(),
      },
      {
        kind: "transaction",
        ...proxy.methods.getPrice([tokenId]).toTransferParams(),
      });
      return batch;
    }
const batchArray = [
      ...updBorrowed,
      {
        kind: "transaction",
        ...yupana.methods.updateInterest(borrowTokenId).toTransferParams(),
      },
      {
        kind: "transaction",
        ...proxy.methods.getPrice([borrowTokenId]).toTransferParams(),
      },
      {
        kind: "transaction",
        ...yupana.methods.borrow(borrowTokenId, amount).toTransferParams(),
      },
    ];
const batch = await tezos.wallet.batch(batchArray);
const operation = await batch.send();
await operation.confirmation();

🐍 Pytezos

token_id = 0
amount = 10_000_000 # amount of borrow tokens.
yupana = ContractInterface.from_michelson(code) # or client.contract(contract_address)...
proxy = ContractInterface.from_michelson(prx_code) # or client.contract(prx_contract_address)...proxy = ContractInterface.from_michelson(code) # or client.contract(contract_address)...
borrow_ids = [1, 2] # user borrowed tokens
borrow_updates = [yupana.updateInterest(borrow_token_id) for borrow_token_id in borrow_ids]
borrow_updates.append(proxy.getPrice([borrow_token_id for borrow_token_id in borrow_ids]))
call = pytezos.bulk(
        *borrow_updates,
        yupana.updateInterest(token_id),
        proxy.getPrice([token_id]),
        yupana.borrow(token_id, amount)
    ).autofill().sign()
opg = call.inject()

Errors

• yToken/max-market-limit - limit of borrow markets exceeded.

• yToken/forbidden-for-borrow - market is paused for borrow.

• yToken/exceeds-the-permissible-debt - raised when outstanding borrow value greater than max collateral value.

• yToken/not-enough-liquidity - not enough liquidity of tokens to send amount wanted by user.

• token/cant-get-contract-token - FA12 token contract address does not contain transfer entrypoint from FA12 interface.

• token/cant-get-contract-fa2-token - FA2 token contract address does not contain transfer entrypoint from FA2 interface.

• underflow/liquidity - reserves - liquidity more than reserves.

• yToken/amount-is-zero - passed zero amount.

• ceil-div-error - division of two numbers fails.

• yToken/need-update - token price and interest not updated (see warning above)

• yToken/yToken-undefined - token identifier is not assigned to any known yTokens.