Supply & Borrow

The lending and borrowing services cover the core money-market loop: supply assets to earn yield, post collateral, borrow against it, and repay. Both services expose buildXTx methods (unsigned transactions) alongside convenience methods that sign and submit through a wallet kit.

All amounts are human-readable; you pass the token's decimal precision so the SDK can scale to on-chain values. See Core patterns for the shared kit, withBuffer, and options conventions.

Lending service

Accessed via client.lending.

---

deposit

Supply assets to a pool and receive jTokens (supply shares) in your obligation.

import type { ObligationKey } from '@alula/market-sdk'

const user: ObligationKey = { user: 'GABC...', seed: undefined }

await client.lending.deposit(user, poolAddress, 100, assetDecimals, kit)

Parameter	Type	Description
user	ObligationKey	Obligation receiving the deposit
poolAddress	string	Target pool address
amount	number	Human-readable amount to deposit
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildDepositTx(user, poolAddress, amount, assetDecimals).

---

withdraw

Redeem jTokens for the underlying asset. The amount actually withdrawn may be capped to keep the obligation healthy.

// Withdraw a specific amount
await client.lending.withdraw(user, poolAddress, 50, assetDecimals, kit, false)

// Withdraw the maximum currently available
await client.lending.withdraw(user, poolAddress, 0, assetDecimals, kit, true)

Parameter	Type	Description
user	ObligationKey	Obligation to withdraw from
poolAddress	string	Target pool address
amount	number	Human-readable amount (ignored when withBuffer is true)
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
withBuffer	boolean	When true, submits the maximum and lets the contract cap it
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildWithdrawTx(user, poolAddress, amount, assetDecimals).

TIP

Call simulateWithdraw first to show the user the exact amount and fees before committing.

---

addCollateral

Post assets as collateral to back borrowing.

await client.lending.addCollateral(user, poolAddress, 100, assetDecimals, kit)

Parameter	Type	Description
user	ObligationKey	Obligation receiving the collateral
poolAddress	string	Target pool address
amount	number	Human-readable amount to add
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildAddCollateralTx(user, poolAddress, amount, assetDecimals).

---

removeCollateral

Release collateral back to your balance, subject to remaining health.

// Remove a specific amount
await client.lending.removeCollateral(user, poolAddress, 25, assetDecimals, kit, false)

// Remove the maximum currently allowed
await client.lending.removeCollateral(user, poolAddress, 0, assetDecimals, kit, true)

Parameter	Type	Description
user	ObligationKey	Obligation to remove collateral from
poolAddress	string	Target pool address
amount	number	Human-readable amount (ignored when withBuffer is true)
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
withBuffer	boolean	When true, submits the maximum and lets the contract cap it
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildRemoveCollateralTx(user, poolAddress, amount, assetDecimals).

Borrowing service

Accessed via client.borrowing.

---

borrow

Borrow an asset against collateral already posted in your obligation. Borrowing capacity is limited by collateral value, open LTV, and liability factors.

await client.borrowing.borrow(user, poolAddress, 200, assetDecimals, kit, false)

Parameter	Type	Description
user	ObligationKey	Obligation borrowing the asset
poolAddress	string	Pool to borrow from
amount	number	Human-readable amount (ignored when withBuffer is true)
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
withBuffer	boolean	When true, submits the maximum borrowable
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildBorrowTx(user, poolAddress, amount, assetDecimals).

WARNING

An obligation cannot hold a deposit and a borrow in the same pool. To earn yield on an asset you are also borrowing, use a separate obligation (a different seed).

---

repay

Repay borrowed assets.

await client.borrowing.repay(user, poolAddress, 100, assetDecimals, kit)

Parameter	Type	Description
user	ObligationKey	Obligation repaying the debt
poolAddress	string	Pool the debt is owed to
amount	number	Human-readable amount to repay
assetDecimals	number	Decimal precision of the pool's token
kit	SigningKit	Wallet used to sign
options	{ debug?: boolean }	Optional; debug defaults to true

Build-only variant: buildRepayTx(user, poolAddress, amount, assetDecimals).