Arc ↔ Base CCTP V2 Bridge

An open-source, non-custodial reference implementation for transferring native USDC between Arc Mainnet and Base Mainnet with Circle CCTP V2.

The standard bridge is live and mainnet-only. Relay, gasless, refuel, and yield features are intentionally disabled until their separate security and operational requirements are complete.

Mainnet software: Transactions move real USDC and require source-chain gas plus destination-chain gas for minting. This project has not received an independent security audit. Verify all addresses against Circle and Arc's official documentation before using or modifying it.

Live scope

Capability	Status
Standard Arc ↔ Base CCTP V2 bridge	Enabled
Resumable burn, attestation, and mint	Enabled
Relay	Disabled pending reviewed deployment and durable payout processing
ERC-4337 gasless mode	Disabled pending provider support and paymaster review
Gas refuel	Disabled pending payout verification and funded liquidity
Yield	Disabled until a real strategy is selected
Testnet runtime	Removed

No application fee is charged by the enabled bridge.

Supported networks

Network	Chain ID	CCTP domain	Native USDC
Arc Mainnet	5042	26	0x3600000000000000000000000000000000000000
Base Mainnet	8453	6	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Circle CCTP V2 mainnet contracts used on both networks:

Contract	Address
TokenMessenger	0x28b5a0e9C621a5BadaA536219b3a228C8168cf5d
MessageTransmitter	0x81D40F21F12A8F0E3252Bccb954D722d4c464B64

Production attestations use https://iris-api.circle.com.

Transfer lifecycle

sequenceDiagram
    participant User
    participant Source as Source TokenMessenger
    participant Iris as Circle Iris
    participant Destination as Destination MessageTransmitter

    User->>Source: approve USDC
    User->>Source: depositForBurn (CCTP V2)
    Source-->>User: burn transaction receipt + MessageSent
    User->>Iris: poll production attestation API
    Iris-->>User: message + attestation
    User->>Destination: receiveMessage
    Destination-->>User: native USDC minted

Loading

The app persists an in-progress session as soon as a burn hash exists. If the wallet RPC fails after broadcasting, the app checks the authoritative source RPC and resumes that transfer instead of inviting a duplicate burn.

Mainnet verification

A real 0.10 USDC Arc → Base → Arc canary completed successfully:

Stage	Transaction
Arc burn	0x987b…31be
Base mint	0x1878…6462
Base burn	0x2e48…19d
Arc mint	0x59cc…bc23

See Mainnet validation for the tested parameters, recovery guarantees, and limitations.

Run locally

Requirements: Node.js 20+ and pnpm 10+.

git clone https://github.com/osr21/arc-relay-bridge.git
cd arc-relay-bridge
pnpm install
pnpm --filter @workspace/arc-bridge run dev

The standard browser bridge does not need a deployer key, API key, or backend signer. Optional server and contract-development variables are documented in .env.example; real values must remain in secret storage.

pnpm --filter @workspace/arc-bridge run typecheck
pnpm --filter @workspace/scripts exec tsx --test \
  ../artifacts/arc-bridge/src/lib/bridge.mainnet.test.ts

Documentation

• Architecture and product scope
• Mainnet validation
• Technical reference
• Development guide
• Contributing
• Security policy
• Deferred relay protocol

Testnet contracts and experiments may remain in the repository for historical development work, but they are not imported by the mainnet runtime and are not part of this release.

Official references

• Connect to Arc
• Circle CCTP contract addresses
• Circle USDC addresses
• Circle CCTP overview
• Base network information

License

Apache-2.0. See LICENSE.