This utility library exists to create and work with 2D nonces as discribed in the Eth-Infinitism document. The implementation can be found in their EntryPoint.
This lib has been checked against what is currently deployed by Eth-Infinitism which is Release v0.6 on ethereum at 0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789
To use the library, install it:
yarn add @beamnetwork/nonce-2d
The 2D nonce is devided into 2 parts. It is 256 bits long, with 192 bits reserved for a key and 64 reserved for numerical sequence that increments for each tx.
nonce-2d = [192 key | 64 seq]
The key portion of the nonce consists of the 192 bit eth address of the sender and a 32 bit slot that can be used to encode transaction metadata. In cases where that metadata you want to encode exceeds the 32 bits limit, you can encode an UID instead which can be used to look up the metadata in another location.
key = [32 bit chain| 160 bit eth address]
To generate the key for a given (address, metadata) = ('0xe7f1725e7734ce288f8367e1bb143e90bb3f0512', '5'):
Nonce2D.getHexKeyForDestination('0xe7f1725e7734ce288f8367e1bb143e90bb3f0512', '5')
To parse a 2d nonce that is already on chain:
Nonce2D.fromHexNonce('0x5e7f1725e7734ce288f8367e1bb143e90bb3f05120000000000000001')
Once you have the Nonce2D object, you can call it to increment its sequence nonce and use it for a tx:
const nonce = Nonce2D.fromHexNonce('0x5e7f1725e7734ce288f8367e1bb143e90bb3f05120000000000000001')
const txNonceHex = nonce.increment().toHexNonce()