Bridge USDC Across Chains

Transfer USDC across 6+ testnets using Circle's CCTP V2 protocol. Native USDC, no wrapped tokens.

Overview

Quantum DEX integrates Circle's Cross-Chain Transfer Protocol (CCTP) V2 for native USDC transfers between chains.

Features

• Native USDC transfer without wrapped tokens
• 6+ supported testnets
• 2 minute total transfer time
• Powered by Circle's audited CCTP V2
• Real-time transaction tracking
• Automatic mint recovery system

Supported Networks

Network	Chain ID	Status
Arc Testnet	5,042,002	Active
Base Sepolia	84,532	Active
Ethereum Sepolia	11,155,111	Active
Arbitrum Sepolia	421,614	Active
Optimism Sepolia	11,155,420	Active
Polygon Amoy	80,002	Active

How It Works

Three-Step Process

1. Burn on Source Chain

• USDC is burned via TokenMessenger contract
• Burn transaction confirmed on-chain
• Takes 10-30 seconds

2. Attestation

• Circle's attestation service verifies the burn
• Signs cryptographic proof
• Takes 60-90 seconds

3. Mint on Destination Chain

• Use attestation to mint USDC on destination
• Native USDC appears in wallet
• Takes 10-30 seconds

Total Time: ~2 minutes

Why CCTP

• No wrapped tokens or synthetic assets
• No liquidity pools required
• Audited by leading security firms
• Permissionless protocol
• Official Circle infrastructure

Bridge Guide

Prerequisites

• Connected wallet (MetaMask, WalletConnect, or Privy)
• USDC on source chain
• Gas tokens on both chains
• 2 minutes for complete transfer

Step 1: Select Networks

1. Navigate to Bridge tab
2. Select source chain (where your USDC is)
3. Select destination chain (where you want USDC)

Click the swap icon between chains to reverse direction.

Step 2: Enter Amount

Manual Entry: Type USDC amount to bridge

MAX Button: Bridge all available USDC (system reserves gas amount)

Limits:

• Minimum: 1 USDC
• Maximum: 10,000 USDC per transaction
• Fee: ~0.1% or $0.10 minimum

Step 3: Approve USDC (First Time Only)

If bridging from a network for the first time:

1. Click "Approve USDC"
2. Confirm approval transaction in wallet
3. Wait for confirmation (5-15 seconds)

This allows the TokenMessenger contract to burn your USDC. One-time approval per network.

Step 4: Execute Burn

1. Click "Bridge" button
2. Review transaction details:
   • Contract: TokenMessenger
   • Function: depositForBurn
   • Amount: Your USDC amount
   • Gas fee: ~$0.01-0.05
3. Confirm transaction
4. Wait for burn confirmation (10-30 seconds)

Step 5: Wait for Attestation

Circle's attestation service verifies your burn and generates cryptographic proof.

Duration: 60-90 seconds

Progress Tracking:

• Real-time progress bar
• Estimated time remaining
• Current status display

You can minimize the modal or close the browser. Progress is saved to localStorage.

Step 6: Mint on Destination Chain

Once attestation is ready:

1. Switch to destination network (MetaMask will prompt)
2. Ensure you have gas tokens
3. Click "Mint USDC"
4. Review mint transaction:
   • Contract: MessageTransmitter
   • Function: receiveMessage
   • Gas fee: ~$0.02-0.10
5. Confirm transaction
6. Wait for confirmation (10-30 seconds)

USDC now appears in your destination wallet.

Step 7: Verify Receipt

Confirm bridge completion:

• Burn transaction confirmed on source chain
• Attestation received
• Mint transaction confirmed on destination chain
• USDC balance updated in wallet
• Both transactions visible on block explorers

Transaction Status

Approving: Waiting for USDC approval (first-time only)

Burning: USDC being destroyed on source chain

Waiting for Attestation: Circle verifying burn (60-90 seconds)

Ready to Mint: Attestation received, switch to destination chain

Success: Bridge complete, USDC received

Error: Check error message and troubleshooting section

Mint Recovery System

If mint transaction fails or is cancelled, your USDC is not lost.

Recovery Process:

1. Attestation data saved to localStorage
2. "Retry Mint" button appears in error modal
3. Click retry anytime (even days later)
4. Switch to destination network
5. Confirm mint transaction
6. Receive USDC

Recovery data persists across browser sessions.

Fees

Bridge Fee

~0.1% or $0.10 minimum

Examples:

• $100 USDC: $0.10 fee
• $1,000 USDC: $1.00 fee
• $50 USDC: $0.10 fee (minimum)

Gas Fees

Source Chain:

• Approval: ~$0.01 (one-time)
• Burn: ~$0.02-0.05

Destination Chain:

• Mint: ~$0.02-0.10

Total Example:

Bridge: $100 USDC
Bridge Fee: $0.10
Source Gas: $0.03
Destination Gas: $0.05
Total: $0.18

Transaction Limits

Testnet:

• Minimum: 1 USDC
• Maximum: 10,000 USDC per transaction
• Daily: Unlimited

Mainnet (when launched):

• Limits will be announced
• Dynamic based on liquidity
• Rate limits may apply

Common Scenarios

Arc to Ethereum

Move USDC from Arc to Ethereum for DeFi access.

Gas Required:

• Arc: ARC token for burn
• Ethereum: ETH for mint

Time: ~2 minutes

Ethereum to Arbitrum

Move to Arbitrum for lower transaction fees.

Benefits:

• Lower gas costs
• Faster confirmations
• More DeFi options

Time: ~2 minutes

Multi-Hop Bridging

Example: Arc → Base → Optimism

1. Bridge Arc → Base (wait for completion)
2. Bridge Base → Optimism (wait for completion)
3. Total time: ~4 minutes

Useful for accessing networks not directly connected.

Troubleshooting

Transaction Failed During Burn

Causes:

• Insufficient USDC balance
• Not enough gas tokens
• USDC not approved
• Network congestion

Solutions:

• Verify USDC balance
• Ensure sufficient gas
• Re-approve USDC
• Retry with higher gas price

Attestation Taking Long

Expected: 60-90 seconds Maximum: 3-5 minutes during congestion

Actions:

• Wait (normal behavior)
• Minimize modal and check later
• Verify burn transaction confirmed
• Do not attempt another bridge

Check burn transaction on block explorer to verify finalization.

Failed Network Switch

Solutions:

1. Manually switch network in wallet
2. Add destination network if missing
3. Refresh page and retry
4. Check wallet connection

Mint Transaction Failed

Your USDC is safe. The recovery system prevents loss.

Solutions:

1. Verify gas on destination chain
2. Use "Retry Mint" button
3. Confirm attestation still valid
4. Increase gas limit if needed
5. Check destination chain status

Lost Attestation Data

Attestation data persists in localStorage and should not be lost.

If lost:

1. Do not bridge again
2. Check localStorage for quantum-bridge-storage
3. Contact support with burn transaction hash
4. Retrieve attestation from Circle's API manually

Best Practices

Before Bridging

• Verify USDC balance on source chain
• Ensure gas on both source and destination chains
• Double-check network selections
• Review amounts carefully
• Check current gas prices

During Bridge

• Save burn transaction hash
• Do not close browser during burn confirmation
• Minimize modal after burn succeeds
• Keep destination chain gas ready

After Attestation

• Switch to destination network promptly
• Verify gas availability before minting
• Execute mint immediately when ready
• Verify USDC received
• Save both transaction hashes

Security

Official Contracts

Only interact with verified CCTP contracts. Always verify contract addresses in your wallet before confirming transactions.

Check website URL: www.quantumexchange.app

Never Share

• Transaction signatures
• Attestation data with untrusted parties
• Private keys or seed phrases
• Wallet passwords

Be Careful With

• Custom RPC endpoints
• Unknown websites
• Unsolicited support messages
• Requests to "validate" wallet

Scam Prevention

Red Flags:

• Website asks for seed phrase
• Unsolicited DMs offering support
• Requests to connect to unknown sites
• Promises to "speed up" attestation
• Offers to "recover" stuck bridges for fee

Legitimate Support:

• Official Quantum Twitter
• Documentation
• Circle official channels
• On-chain verification

Advanced

Manual Attestation Retrieval

If automatic attestation fails:

1. Get burn transaction hash
2. Query Circle's attestation API:

   https://iris-api-sandbox.circle.com/attestations/{burnTxHash}

3. Copy attestation signature
4. Use with receiveMessage function
5. Complete mint manually

Message Format

CCTP messages contain:

• Source domain (chain identifier)
• Destination domain
• Nonce (unique per message)
• Sender and recipient addresses
• Amount (USDC atomic units)
• Message body hash

Monitoring Activity

Block Explorers:

• Source chain: View burn transaction
• Destination chain: View mint transaction

Circle APIs:

• Attestation service status
• Message transmission logs
• Historical bridge data

FAQ

How long does bridging take?

Total time: ~2 minutes

• Burn: 10-30 seconds
• Attestation: 60-90 seconds
• Mint: 10-30 seconds

Can I cancel a bridge?

• Before burn: Yes, close modal
• After burn: No, USDC already burned
• During attestation: No, but retry mint later available

What if I lose attestation?

Attestation is saved in browser localStorage and retrievable from Circle's API using burn transaction hash.

Do I pay fees twice?

• Gas fees: Yes (both chains)
• Bridge fee: Once (on burn)

What is minimum amount?

• Testnet: 1 USDC
• Mainnet: To be announced

Is bridging secure?

Yes. CCTP is audited by leading firms, battle-tested on mainnet, and run by Circle (USDC issuer).

Next Steps

• Understand CCTP Protocol
• Add Liquidity
• Swap Tokens

Support

• FAQ
• Security Best Practices
• Twitter
• Circle CCTP Documentation