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Function Signature

func GetChainByDomain(domain uint32, testnet bool) (*Chain, error)
Returns a specific chain configuration by looking up its CCTP domain identifier. This is useful when you have a domain ID from a CCTP message or transaction and need the corresponding chain details.

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Parameters

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domain
uint32
required
The CCTP domain identifier to search for. Each chain has a unique domain ID (e.g., Ethereum = 0, Avalanche = 1, OP Mainnet = 2)
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testnet
bool
required
Set to true to search testnet chains, or false to search mainnet chains

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Returns

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chain
*Chain
Pointer to a Chain struct containing the blockchain configuration, or nil if not found. The Chain includes:
  • Name (string) - Chain name
  • ChainID (*big.Int) - EVM chain ID
  • Domain (uint32) - CCTP domain identifier
  • RPC (string) - Default RPC endpoint URL
  • TokenMessengerV2 (string) - TokenMessenger V2 contract address
  • MessageTransmitterV2 (string) - MessageTransmitter V2 contract address
  • USDC (string) - USDC token contract address
  • Explorer (string) - Block explorer URL
  • IsTestnet (bool) - Whether this is a testnet chain
  • InstantFinality (bool) - Whether the chain has instant finality
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error
error
Error if the chain with the specified domain is not found. Returns nil if successful.

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Usage Example

package main

import (
    "fmt"
    "github.com/circlefin/cctp-go"
)

func main() {
    // Get Ethereum mainnet (domain 0)
    chain, err := cctp.GetChainByDomain(0, false)
    if err != nil {
        panic(err)
    }
    
    fmt.Printf("Chain: %s\n", chain.Name)
    fmt.Printf("Chain ID: %s\n", chain.ChainID.String())
    fmt.Printf("RPC: %s\n", chain.RPC)
    fmt.Printf("USDC: %s\n", chain.USDC)
    
    // Get Arbitrum mainnet (domain 3)
    arbitrum, err := cctp.GetChainByDomain(3, false)
    if err != nil {
        panic(err)
    }
    
    fmt.Printf("\nChain: %s\n", arbitrum.Name)
    fmt.Printf("Domain: %d\n", arbitrum.Domain)
    
    // Get Base Sepolia testnet (domain 6)
    baseSepolia, err := cctp.GetChainByDomain(6, true)
    if err != nil {
        panic(err)
    }
    
    fmt.Printf("\nTestnet Chain: %s\n", baseSepolia.Name)
    fmt.Printf("Explorer: %s\n", baseSepolia.Explorer)
    
    // Handle chain not found
    _, err = cctp.GetChainByDomain(999, false)
    if err != nil {
        fmt.Printf("\nError: %s\n", err.Error())
        // Output: Error: chain with domain 999 not found
    }
}

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Common Domain IDs

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Mainnet

  • 0 - Ethereum
  • 1 - Avalanche
  • 2 - OP Mainnet
  • 3 - Arbitrum
  • 6 - Base
  • 7 - Polygon PoS
  • 10 - Unichain
  • 11 - Linea
  • 12 - Codex
  • 13 - Sonic
  • 14 - World Chain
  • 16 - Sei
  • 18 - XDC
  • 19 - HyperEVM
  • 21 - Ink
  • 22 - Plume

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Testnet

  • 0 - Ethereum Sepolia
  • 1 - Avalanche Fuji
  • 2 - OP Sepolia
  • 3 - Arbitrum Sepolia
  • 6 - Base Sepolia
  • 7 - Polygon PoS Amoy
  • 10 - Unichain Sepolia
  • 11 - Linea Sepolia
  • 12 - Codex Testnet
  • 13 - Sonic Testnet
  • 14 - World Chain Sepolia
  • 16 - Sei Testnet
  • 18 - XDC Apothem
  • 19 - HyperEVM Testnet
  • 21 - Ink Testnet
  • 22 - Plume Testnet
  • 26 - Arc Testnet
This function searches through all chains returned by GetChains() and returns the first match. Domain IDs are unique within mainnet and testnet environments.

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Error Handling

The function returns an error with the message "chain with domain %d not found" if no chain matches the specified domain ID.

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