algo-flash-loan-sdk v1.0.3

algo-fl4sh-loan-sdk

Algorand FL4SH LOAN client for javascript.

What it is / How it works / Why would I use it / etc

Read the FL4SH LOAN documentation here.

Installation

npm i algo-fl4sh-loan-sdk

or

yarn algo-fl4sh-loan-sdk

Example use

See also: examples/ for a standalone example.

import algosdk from 'algosdk';
import { makeLoanTxn, signLoanTxn } from 'algo-fl4sh-loan-sdk';

const algod = new algosdk.Algodv2("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "http://localhost", "4001");

const mnem = 'essay glory sponsor now detect bitter first arrive elder noble immense direct shock forest whale relief puppy coast initial blood salute total cube about expect';

const { addr, sk } = algosdk.mnemonicToSecretKey(mnem);

const suggestedParams = await algod.getTransactionParams().do();

// unsignedLoanTxn: the loan from the logic sig to "addr"
// unsignedRepayTxn: an example repayment txn back to the logic sig
// repayAmount: use if you want to create your own repayment transaction
const [unsignedLoanTxn, unsignedRepayTxn, repayAmount] = await makeLoanTxn({
  algosdk,
  algod, 
  fees: 10_000,
  receiver: addr,
  amount: 1_000_000,
});

// group the transactions
// loan txn MUST be first
// repayment txn MUST be last
// repayment can be from any address
// repayment MUST be an outer payment - CAN NOT be from an inner transaction in an app call
algosdk.assignGroupID([unsignedLoanTxn, /* your other transactions go here */ unsignedRepayTxn]);

// sign and submit
const signed = [
  signLoanTxn(unsignedLoanTxn, algosdk).blob,
  algosdk.signTransaction(unsignedRepayTxn, sk).blob,
];

try {
  const { txId } = await algod.sendRawTransaction(signed).do();
  console.log('OK', txId);
} catch(e) {
  console.error(e);
}

Exported functions

Note: All functions expect algosdk to be passed as a parameter.

async makeLoanTxn

makeLoanTxn returns the first and last transactions (unsigned) to be placed in the transaction group.

Call with parameters:

const [unsignedLoanTxn, unsignedRepayTxn, repayAmount] = await makeLoanTxn({
  algosdk,
  receiver,
  amount,
  fees,
  suggestedParams,
  algod,
});

Object parameter values:

• algosdk: required. pass in the js-algorand-sdk you are using on your client.
• receiver: required. address of loan recipient.
• amount: required. can be 0. amount to withdraw.
• fees: optional. Flat fee to set in the loan transaction. Will default to suggestedParams or query suggested parameters from algod.
• suggestedParams: optional2. Suggested parameters to use. if fees is also provided, flatFee will be set to true and fee will be set to the fees value
• algod: optional2. Algod v2 client to query suggested parameters.

* optional2: one of algod or suggestedParams is required

Return values: Array of:

• Unsigned loan transaction. Goes first in the group.
• Unsigned loan repayment transaction. Goes last in the group.
• Repayment amount. Use this in case you want to repay the loan from a different account.

signLoanTxn

Signs a loan txn with the logic sig.

const signed = signLoanTxn(unsignedLoanTxn, algosdk);

Arguments:

• unsignedLoanTxn: unsigned loan transaction as generated from makeLoanTxn
• algosdk: your algosdk

Returns:

Signed transaction, containing: { txID, blob }

getAddress

Returns the fl4sh loan logic sig address: FL4SHLOANLERAK6AFTBSBIL2WIWCRUFY7XWQK57H3EXM6GMMGMPT7C3UKI

const address = getAddress(algosdk);

Arguments:

• algosdk

getLsig

Returns a LogicSigAccount (algosdk class)

const lsigAccount = getLsig(algosdk);