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CCTP Receive

CCTP enables USDC to be received on Noble from a counterparty chain. At the time of writing, the source chain can be Ethereum, Avalanche, Optimism, or Arbitrum.

High level flow​

  • User calls smart contract to burn the tokens on the source chain
  • CCTP relayer observes finalized burn and requests Attestation from Circle Iris API
  • Circle Iris API proves burn and issues attestation
  • CCTP relayer broadcasts the message and attestation to Noble
  • Noble processes the CCTP BurnMessage and mints the token to the Noble recipient

Deposit For Burn​

Circle's Deposit For Burn contract includes four function parameters which are highlighted below.

function depositForBurn(
    uint256 amount,
	uint32 destinationDomain,
    bytes32 mintRecipient,
    address burnToken,
) external returns (uint64 nonce)

Let's expand on what each of these parameters means:

  • amount - The amount of tokens to transfer (burned on the source chain and minted on Noble)
  • destinationDomain - The domain ID of the destination chain (4 for Noble)
  • mintRecipient - The address of the recipient on the destination chain (Noble account address - 20 bytes left padded with 12 zeroes)
  • burnToken - The address of the contract to burn tokens on the source chain

Encoding​

Below you will find a simple script that pads & hex encodes both the destination bech32 prefix and recipient.

The highlighted lines indicate inputs you can change to your specific case.

package main

import (
	"encoding/hex"
	"fmt"

	"github.com/cosmos/cosmos-sdk/types/bech32"
)

const address = "noble14lwerrcfzkzrv626w49pkzgna4dtga8c5x479h"

func main() {
	_, rawAddress, _ := bech32.DecodeAndConvert(address)
	encodedAddress := Encode(rawAddress)

	fmt.Println("ENCODED ADDRESS:", encodedAddress)
}

func Encode(bz []byte) (encoded string) {
	padded := make([]byte, 32)
	copy(padded[32-len(bz):], bz)

	return "0x" + hex.EncodeToString(padded)
}

The output of the exact script above is:

ENCODED ADDRESS: 0x000000000000000000000000afdd918f09158436695a754a1b0913ed5ab474f8

Example​

To send 10 USDC from Goerli Ethereum Testnet to Noble, address noble14lwerrcfzkzrv626w49pkzgna4dtga8c5x479h, you would call the following on the Goerli Ethereum Testnet:

depositForBurn(
	0x989680, // 10000000uusdc = 10 USDC
	0x4, //Noble
	0x000000000000000000000000afdd918f09158436695a754a1b0913ed5ab474f8, // noble14lwerrcfzkzrv626w49pkzgna4dtga8c5x479h
	0x07865c6E87B9F70255377e024ace6630C1Eaa37F, // USDC on Goerli Ethereum Testnet
)