For Developers
Smart Contract API
Binance Liquid Staking API

BNB Liquid Staking API

To integrate with BNB Liquid Staking, use the smart contract functions and examples below.

Stake BNB and claim ankrBNB


Stakes BNB and claims ankrBNB.


payableAmount (BNB, required) — amount of BNB to be staked.

Smart contract

Unstake ankrBNB and get BNB

Unstaking ankrBNB is a two-step process:

  1. Approve access to ankrBNB.
  2. Unstake ankrBNB.

approve(spender, amount)

Approve access for the aBNBb contract to the specified amount of ankrBNB.
aBNB is a legacy contract used in Ankr's BNB Liquid Staking.

  • sender (address, required) — address of aBNBb. Possible values:
    • 0xfe39985D7eFF914c50A06bA0cFfcCA8361e00C0e for Mainnet
    • 0x93405327644eDF8aD908e41F9a2Ecbb6714769D1 for Testnet.
  • amount (uint256, required) — amount of ankrBNB to approve access to.
Smart contract


Unstakes ankrBNB and gets BNB for the unstaked ankrBNB.


shares (uint256, required) — amount of ankrBNB to be unstaked.

Smart contract


averagePercentageRate(uint256 day, address addr)

Gets the APR for ankrBNB.

The formula is best expressed by an example.

With 3 provided as the depth, the APR = ((((day 3 - day 2) / day 3) * 100) + ((day 2 - day 1) / day 2) * 100) + ((day 1 - current day) / day 1) * 100) / 3) * 365.

  • day (uint256, required) — number of days to get the APR for. Max value — 7 days.
  • address (address, required) — address of the token contract. The address of ankrBNB is 0x52F24a5e03aee338Da5fd9Df68D2b6FAe1178827.
Smart contract

averagePercentageRate being a read function, we suggest you visit the links and make a query entering a desired number of days to see an example.

Get staking metrics

To integrate Ankr Staking metrics into your dashboards or use metrics like APY in your products, read Liquid Staking Metrics.