CCTP Relayer (old) - Noble to Solana & EVM

Note: This tool uses CCTP V1 (Legacy). Circle is deprecating V1 in favour of CCTP V2, with phase-out beginning July 2026. V1 remains fully functional until then, but a migration to V2 will be needed in the future.

A community-built tool for recovering and sending USDC transfers from Noble (Cosmos) using Circle's Cross-Chain Transfer Protocol (CCTP V1). Supports relaying to Solana and all major EVM chains: Ethereum, Avalanche, OP Mainnet, Arbitrum, Base, and Polygon PoS.

Buy me a coffee

This is an independent, community-built tool and is not affiliated with or endorsed by Circle, Solana, Phantom, MetaMask, or any other referenced project.

Live deployments

• Vercel: https://cctp-relayer.vercel.app/
• GitHub Pages: https://jasbanza.github.io/cctp-relayer/

Features

• Recover transfers: Fetch Noble transaction details, extract the CCTP message, and relay to the destination chain
• Send USDC: Burn USDC on Noble and prepare a CCTP transfer to any supported destination
• Lookup pending transfers: Search for in-flight transfers by destination address
• Multi-chain support: Relay to Solana (Phantom) or any EVM chain (MetaMask / injected wallet)
• Auto-detection: Destination chain is detected automatically from the CCTP message
• Compute keccak256 message hash and fetch Circle attestation
• All fields are editable for power users
• External tool links for manual fallback

Usage

Recover a Transfer

1. Enter your Noble transaction hash
2. Click "Fetch TX" to retrieve the message data (the tool will auto-convert to hex, compute the hash, and fetch the attestation)
3. Wait until the attestation status shows complete
4. The destination chain is detected automatically — connect the appropriate wallet:
   • Solana: Connect Phantom wallet, then click "Relay to Solana"
   • EVM chains: Connect MetaMask (or any injected wallet), then click "Relay to [Chain]"

Send USDC from Noble

1. Connect your Keplr wallet
2. Select the destination chain and enter the recipient address
3. Enter the amount and send

Lookup Pending Transfers

Enter a destination address (Solana or EVM) to search for in-flight CCTP transfers waiting to be relayed.

Manual Entry

If you already have any intermediate values (message hash, attestation, etc.), you can paste them directly into the corresponding fields.

Project Structure

cctp-relayer/
├── api/                    # Vercel serverless functions
│   ├── blockhash.js        # GET /api/blockhash (proxies Solana RPC)
│   ├── config.js           # Allowed origins config
│   └── relay.js            # POST /api/relay (proxies Solana RPC)
├── public/                 # Static website files
│   ├── app.js              # Main application logic (all chains)
│   ├── index.html
│   └── styles.css
├── .github/workflows/      # CI/CD
│   └── deploy-gh-pages.yml # Auto-deploy to GitHub Pages
├── .gitignore
├── package.json
└── README.md

Hosting

Vercel (Recommended)

The API proxy keeps your Helius RPC key secret while allowing CORS from your domains.

1. Push to GitHub
2. Import repo at vercel.com
3. Add environment variable:
   • HELIUS_RPC_URL = https://mainnet.helius-rpc.com/?api-key=YOUR_KEY
4. Deploy

To update allowed origins, edit api/config.js and redeploy.

Local Testing

yarn install
yarn dev

Note: The /api/* proxy won't work locally (falls back to direct RPC).

GitHub Pages (Static only)

If you don't need the RPC proxy, you can host just the public/ folder on GitHub Pages. The app will fall back to the direct Solana RPC configured in the UI.

Configuration

All configuration values can be edited in the UI:

Field	Default	Description
Noble LCD API	https://noble-api.polkachu.com	Noble REST API endpoint
Solana RPC	https://rpc.ankr.com/solana	Solana RPC endpoint (fallback)
Circle Attestation API	https://iris-api.circle.com/v1/attestations	Circle's attestation service
MessageTransmitter	CCTPmbSD7gX1bxKPAmg77w8oFzNFpaQiQUWD43TKaecd	Solana CCTP program
TokenMessengerMinter	CCTPiPYPc6AsJuwueEnWgSgucamXDZwBd53dQ11YiKX3	Solana CCTP program

EVM chain contract addresses (MessageTransmitter, TokenMessenger) are auto-configured based on the selected destination chain.

Domain IDs

Chain	Domain ID
Ethereum	0
Avalanche	1
OP Mainnet	2
Arbitrum	3
Noble	4
Solana	5
Base	6
Polygon PoS	7

Manual Fallback Tools

If any step in the UI fails, you can use these external tools:

Source Transaction

• Mintscan Noble Explorer - View Noble transactions
• Noble LCD API - Query transactions directly
• Base64 to Hex Converter - Convert message encoding

Attestation

• Keccak256 Hash Tool - Compute message hash (use hex input)
• Circle Attestation API - Fetch attestation directly
• Message Format Docs - Understand CCTP message structure

Relay

• Phantom Wallet - Solana wallet
• MetaMask - EVM wallet
• Solscan Explorer - View Solana transactions
• Etherscan, Basescan, Arbiscan - View EVM transactions
• CCTP Solana Contracts - Solana source code reference
• EVM CCTP Contracts - EVM contract addresses

Troubleshooting

CORS Issues

If the Circle attestation API fails due to CORS, you can:

1. Manually fetch the attestation: curl https://iris-api.circle.com/v1/attestations/{hash}
2. Paste the attestation value directly into the UI

Transaction Simulation Failed

Check that:

• The attestation status is "complete"
• The message hasn't already been relayed (nonce already used)
• Your wallet has enough native tokens for gas (SOL for Solana, ETH for Ethereum/Base/Arbitrum/OP, MATIC for Polygon, AVAX for Avalanche)
• For EVM relays, your wallet is connected to the correct network (the app will prompt to switch)

Message Not Found in Transaction

The transaction may use a different event format. Check the browser console for the raw transaction events and manually extract the message.

Technical Details

Message Format

CCTP messages follow this structure:

• Header: version (4) + sourceDomain (4) + destDomain (4) + nonce (8) + sender (32) + recipient (32) + destCaller (32)
• Body: version (4) + burnToken (32) + mintRecipient (32) + amount (32) + messageSender (32)

Attestation

The attestation is Circle's signature over the keccak256 hash of the message bytes. It proves the message was legitimately sent on the source chain.

References

• CCTP Overview
• CCTP Supported Domains
• CCTP Solana Programs
• Noble CCTP Module
• CCTP API Reference

License

MIT