> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Before reading these docs, install the relevant Circle Skill to get pre-loaded context — skills are LLM-optimized and cover architecture decisions, correct flows, and common pitfalls. In Claude Code: run /plugin marketplace add circlefin/skills then /plugin install circle-skills@circle. With Vercel Skills CLI: run npx skills add circlefin/skills. Available skills: use-usdc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-usdc/SKILL.md (balances, transfers, approvals on EVM and Solana); EURC has no skill — see https://developers.circle.com/stablecoins/what-is-eurc.md; bridge-stablecoin https://github.com/circlefin/skills/blob/master/plugins/circle/skills/bridge-stablecoin/SKILL.md (crosschain transfers via CCTP, USDC, EURC, and third-party assets); use-arc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-arc/SKILL.md (Arc chain config, contract deployment, USDC bridging — Arc docs: https://docs.arc.io/llms.txt); use-circle-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-circle-wallets/SKILL.md (choose wallet type); use-developer-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-developer-controlled-wallets/SKILL.md (custodial wallets for payouts and treasury); use-user-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-user-controlled-wallets/SKILL.md (embedded wallets with Web2 login); use-modular-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-modular-wallets/SKILL.md (smart contract wallets with passkeys and ERC-4337); use-gateway https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-gateway/SKILL.md (unified USDC balance, nanopayments); use-smart-contract-platform https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-smart-contract-platform/SKILL.md (deploy, interact, monitor contracts). Pair any skill with the Circle MCP server for live SDK signatures, contract addresses, and chain IDs: {"mcpServers":{"circle":{"url":"https://api.circle.com/v1/codegen/mcp"}}}.
> Read the product overview first. Each product has an overview explaining when and why to use it. Read it before quickstarts.
> Pick the right wallet type. Developer-controlled (you hold keys), user-controlled (end user holds keys via PIN/social login), or modular (smart contract wallets with passkeys). See https://developers.circle.com/wallets.md.
> Use CCTP V2 for crosschain transfers. CCTP natively transfers USDC and EURC via burn-and-mint, and supports permissionless wrapping of third-party assets via lock-and-mint. V1 is legacy; always use V2 unless V1 is specified or the chain requires it (Noble, Sui, and Aptos still require V1). Migration guide: https://developers.circle.com/cctp/migration-from-v1-to-v2.md.
> Use Bridge Kit for frontend bridging. Wraps CCTP with a simpler SDK for user-facing apps. Use CCTP directly for backend transfers.
> Gas Station vs Paymaster. Gas Station sponsors gas for Circle Wallet transactions. Paymaster lets users pay gas in USDC. Different use cases — read both overviews.
> Gateway Nanopayments for sub-cent payments. Gasless USDC micropayments down to $0.000001 via x402 and batched settlement. For pay-per-request APIs, AI agent payments, streaming.
> Look up USDC addresses per chain. Never hardcode — use https://developers.circle.com/stablecoins/usdc-contract-addresses.md.
> Prefer SDKs over raw API calls. Node.js and Python SDKs handle auth, retries, and errors.
> API key required. Bearer token in Authorization header. Testnet and mainnet use separate keys and may use different base URLs depending on the product.
> Set up webhooks when available. Most operations are async. Webhooks deliver transaction confirmations and state changes.
> When calling list endpoints, paginate using pageSize and pageAfter until no nextPageAfter cursor is returned—stopping at the first page silently misses records.
> Building an AI agent? Start with the Agent Stack—Circle CLI, agent wallets, and nanopayments built for autonomous use cases: https://developers.circle.com/agent-stack.md.

# CCTP EVM contracts and interfaces V1

> CCTP V1 smart contracts for EVM-compatible blockchains

<Warning>
  **This is CCTP V1 (Legacy) version. For the latest version, see
  [CCTP](/cctp)**.
</Warning>

## Contract responsibilities

* **TokenMessenger**: Entrypoint for cross-chain USDC transfer. Routes messages
  to burn USDC on a source chain, and mint USDC on a destination chain.
* **MessageTransmitter**: Generic message passing. Sends all messages on the
  source chain, and receives all messages on the destination chain.
* **TokenMinter**: Responsible for minting and burning USDC. Contains
  chain-specific settings used by burners and minters.
* **Message**: Provides helper functions for cross-chain transfers, such as
  `bytes32ToAddress` and `addressToBytes32`, which are commonly used when
  bridging between EVM and non-EVM chains. These conversions are simple: prepend
  12 zero bytes to an EVM address, or strip them to convert back.

<Note>
  **Note:** If you're writing your own integration, it's more gas-efficient to
  [include this logic directly in your
  contract](https://github.com/circlefin/evm-cctp-contracts/blob/5f1901a9791b18204e8556bb53fb0dfcb05a832a/src/messages/Message.sol#L146)
  rather than calling an external one.
</Note>

Full contract source code is
[available on GitHub](https://github.com/circlefin/evm-cctp-contracts).

## Mainnet contract addresses

### TokenMessenger: Mainnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum** | 0 | [`0xBd3fa81B58Ba92a82136038B25aDec7066af3155`](https://etherscan.io/address/0xbd3fa81b58ba92a82136038b25adec7066af3155) |
| **Avalanche** | 1 | [`0x6B25532e1060CE10cc3B0A99e5683b91BFDe6982`](https://snowtrace.io/address/0x6b25532e1060ce10cc3b0a99e5683b91bfde6982) |
| **OP Mainnet** | 2 | [`0x2B4069517957735bE00ceE0fadAE88a26365528f`](https://optimistic.etherscan.io/address/0x2B4069517957735bE00ceE0fadAE88a26365528f) |
| **Arbitrum** | 3 | [`0x19330d10D9Cc8751218eaf51E8885D058642E08A`](https://arbiscan.io/address/0x19330d10D9Cc8751218eaf51E8885D058642E08A) |
| **Base** | 6 | [`0x1682Ae6375C4E4A97e4B583BC394c861A46D8962`](https://basescan.org/address/0x1682Ae6375C4E4A97e4B583BC394c861A46D8962) |
| **Polygon PoS** | 7 | [`0x9daF8c91AEFAE50b9c0E69629D3F6Ca40cA3B3FE`](https://polygonscan.com/address/0x9daf8c91aefae50b9c0e69629d3f6ca40ca3b3fe) |
| **Unichain** | 10 | [`0x4e744b28E787c3aD0e810eD65A24461D4ac5a762`](https://uniscan.xyz/address/0x4e744b28E787c3aD0e810eD65A24461D4ac5a762) |

### MessageTransmitter: Mainnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum** | 0 | [`0x0a992d191DEeC32aFe36203Ad87D7d289a738F81`](https://etherscan.io/address/0x0a992d191deec32afe36203ad87d7d289a738f81) |
| **Avalanche** | 1 | [`0x8186359aF5F57FbB40c6b14A588d2A59C0C29880`](https://snowtrace.io/address/0x8186359af5f57fbb40c6b14a588d2a59c0c29880) |
| **OP Mainnet** | 2 | [`0x4D41f22c5a0e5c74090899E5a8Fb597a8842b3e8`](https://optimistic.etherscan.io/address/0x4d41f22c5a0e5c74090899e5a8fb597a8842b3e8) |
| **Arbitrum** | 3 | [`0xC30362313FBBA5cf9163F0bb16a0e01f01A896ca`](https://arbiscan.io/address/0xC30362313FBBA5cf9163F0bb16a0e01f01A896ca) |
| **Base** | 6 | [`0xAD09780d193884d503182aD4588450C416D6F9D4`](https://basescan.org/address/0xAD09780d193884d503182aD4588450C416D6F9D4) |
| **Polygon PoS** | 7 | [`0xF3be9355363857F3e001be68856A2f96b4C39Ba9`](https://polygonscan.com/address/0xF3be9355363857F3e001be68856A2f96b4C39Ba9) |
| **Unichain** | 10 | [`0x353bE9E2E38AB1D19104534e4edC21c643Df86f4`](https://uniscan.xyz/address/0x353bE9E2E38AB1D19104534e4edC21c643Df86f4) |

### TokenMinter: Mainnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum** | 0 | [`0xc4922d64a24675E16e1586e3e3Aa56C06fABe907`](https://etherscan.io/address/0xc4922d64a24675e16e1586e3e3aa56c06fabe907) |
| **Avalanche** | 1 | [`0x420F5035fd5dC62a167E7e7f08B604335aE272b8`](https://snowtrace.io/address/0x420f5035fd5dc62a167e7e7f08b604335ae272b8) |
| **OP Mainnet** | 2 | [`0x33E76C5C31cb928dc6FE6487AB3b2C0769B1A1e3`](https://optimistic.etherscan.io/address/0x33E76C5C31cb928dc6FE6487AB3b2C0769B1A1e3) |
| **Arbitrum** | 3 | [`0xE7Ed1fa7f45D05C508232aa32649D89b73b8bA48`](https://arbiscan.io/address/0xE7Ed1fa7f45D05C508232aa32649D89b73b8bA48) |
| **Base** | 6 | [`0xe45B133ddc64bE80252b0e9c75A8E74EF280eEd6`](https://basescan.org/address/0xe45B133ddc64bE80252b0e9c75A8E74EF280eEd6) |
| **Polygon PoS** | 7 | [`0x10f7835F827D6Cf035115E10c50A853d7FB2D2EC`](https://polygonscan.com/address/0x10f7835f827d6cf035115e10c50a853d7fb2d2ec) |
| **Unichain** | 10 | [`0x726bFEF3cBb3f8AF7d8CB141E78F86Ae43C34163`](https://uniscan.xyz/address/0x726bFEF3cBb3f8AF7d8CB141E78F86Ae43C34163) |

### Message: Mainnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum** | 0 | [`0xB2f38107A18f8599331677C14374Fd3A952fb2c8`](https://etherscan.io/address/0xb2f38107a18f8599331677c14374fd3a952fb2c8) |
| **Avalanche** | 1 | [`0x21F337db7A718F23e061262470Af8c1Fd01232D1`](https://snowtrace.io/address/0x21f337db7a718f23e061262470af8c1fd01232d1) |
| **OP Mainnet** | 2 | [`0xDB2831EaF163be1B564d437A97372deB0046C70D`](https://optimistic.etherscan.io/address/0xdb2831eaf163be1b564d437a97372deb0046c70d) |
| **Arbitrum** | 3 | [`0xE189BDCFbceCEC917b937247666a44ED959D81e4`](https://arbiscan.io/address/0xe189bdcfbcecec917b937247666a44ed959d81e4) |
| **Base** | 6 | [`0x827ae40E55C4355049ab91e441b6e269e4091441`](https://basescan.org/address/0x827ae40E55C4355049ab91e441b6e269e4091441) |
| **Polygon PoS** | 7 | [`0x02d9fa3e7f870E5FAA7Ca6c112031E0ddC5E646C`](https://polygonscan.com/address/0x02d9fa3e7f870E5FAA7Ca6c112031E0ddC5E646C) |
| **Unichain** | 10 | [`0x395b1be6E432033B676e3e36B2c2121a1f952622`](https://uniscan.xyz/address/0x395b1be6E432033B676e3e36B2c2121a1f952622) |

## Testnet contract addresses

### TokenMessenger: Testnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum Sepolia** | 0 | [`0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5`](https://sepolia.etherscan.io/address/0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5) |
| **Avalanche Fuji** | 1 | [`0xeb08f243E5d3FCFF26A9E38Ae5520A669f4019d0`](https://testnet.snowtrace.io/address/0xeb08f243e5d3fcff26a9e38ae5520a669f4019d0) |
| **OP Sepolia** | 2 | [`0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5`](https://sepolia-optimism.etherscan.io/address/0x9f3b8679c73c2fef8b59b4f3444d4e156fb70aa5) |
| **Arbitrum Sepolia** | 3 | [`0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5`](https://sepolia.arbiscan.io/address/0x9f3b8679c73c2fef8b59b4f3444d4e156fb70aa5) |
| **Base Sepolia** | 6 | [`0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5`](https://base-sepolia.blockscout.com/address/0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5) |
| **Polygon PoS Amoy** | 7 | [`0x9f3B8679c73C2Fef8b59B4f3444d4e156fb70AA5`](https://amoy.polygonscan.com/address/0x9f3b8679c73c2fef8b59b4f3444d4e156fb70aa5) |
| **Unichain Sepolia** | 10 | [`0x8ed94B8dAd2Dc5453862ea5e316A8e71AAed9782`](https://unichain-sepolia.blockscout.com/address/0x8ed94B8dAd2Dc5453862ea5e316A8e71AAed9782) |

### MessageTransmitter: Testnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum Sepolia** | 0 | [`0x7865fAfC2db2093669d92c0F33AeEF291086BEFD`](https://sepolia.etherscan.io/address/0x7865fAfC2db2093669d92c0F33AeEF291086BEFD) |
| **Avalanche Fuji** | 1 | [`0xa9fB1b3009DCb79E2fe346c16a604B8Fa8aE0a79`](https://testnet.snowtrace.io/address/0xa9fb1b3009dcb79e2fe346c16a604b8fa8ae0a79) |
| **OP Sepolia** | 2 | [`0x7865fAfC2db2093669d92c0F33AeEF291086BEFD`](https://sepolia-optimism.etherscan.io/address/0x7865fAfC2db2093669d92c0F33AeEF291086BEFD) |
| **Arbitrum Sepolia** | 3 | [`0xaCF1ceeF35caAc005e15888dDb8A3515C41B4872`](https://sepolia.arbiscan.io/address/0xacf1ceef35caac005e15888ddb8a3515c41b4872) |
| **Base Sepolia** | 6 | [`0x7865fAfC2db2093669d92c0F33AeEF291086BEFD`](https://base-sepolia.blockscout.com/address/0x7865fAfC2db2093669d92c0F33AeEF291086BEFD) |
| **Polygon PoS Amoy** | 7 | [`0x7865fAfC2db2093669d92c0F33AeEF291086BEFD`](https://amoy.polygonscan.com/address/0x7865fafc2db2093669d92c0f33aeef291086befd) |
| **Unichain Sepolia** | 10 | [`0xbc498c326533d675cf571B90A2Ced265ACb7d086`](https://unichain-sepolia.blockscout.com/address/0xbc498c326533d675cf571B90A2Ced265ACb7d086) |

### TokenMinter: Testnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum Sepolia** | 0 | [`0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A`](https://sepolia.etherscan.io/address/0xe997d7d2f6e065a9a93fa2175e878fb9081f1f0a) |
| **Avalanche Fuji** | 1 | [`0x4ED8867f9947A5fe140C9dC1c6f207F3489F501E`](https://testnet.snowtrace.io/address/0x4ed8867f9947a5fe140c9dc1c6f207f3489f501e) |
| **OP Sepolia** | 2 | [`0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A`](https://sepolia-optimism.etherscan.io/address/0xe997d7d2f6e065a9a93fa2175e878fb9081f1f0a) |
| **Arbitrum Sepolia** | 3 | [`0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A`](https://sepolia.arbiscan.io/address/0xe997d7d2f6e065a9a93fa2175e878fb9081f1f0a) |
| **Base Sepolia** | 6 | [`0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A`](https://base-sepolia.blockscout.com/address/0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A) |
| **Polygon PoS Amoy** | 7 | [`0xE997d7d2F6E065a9A93Fa2175E878Fb9081F1f0A`](https://amoy.polygonscan.com/address/0xe997d7d2f6e065a9a93fa2175e878fb9081f1f0a) |
| **Unichain Sepolia** | 10 | [`0x7348358C94519Da790DB38638d8c23669d343Bc6`](https://unichain-sepolia.blockscout.com/address/0x7348358C94519Da790DB38638d8c23669d343Bc6) |

### Message: Testnet

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| - | - | - |
| **Ethereum Sepolia** | 0 | [`0x80537e4e8bAb73D21096baa3a8c813b45CA0b7c9`](https://sepolia.etherscan.io/address/0x80537e4e8bAb73D21096baa3a8c813b45CA0b7c9) |
| **Avalanche Fuji** | 1 | [`0xeAf1DB5E3eb86FEbD8080368a956622b62Dcb78f`](https://testnet.snowtrace.io/address/0xeaf1db5e3eb86febd8080368a956622b62dcb78f) |
| **OP Sepolia** | 2 | [`0xffbeA106ce4A3CdAfcC82BAebeD78C81814e32Ed`](https://sepolia-optimism.etherscan.io/address/0xffbeA106ce4A3CdAfcC82BAebeD78C81814e32Ed) |
| **Arbitrum Sepolia** | 3 | [`0x70fAB9868cd54E12C7d87196424d6E0ca21be534`](https://sepolia.arbiscan.io/address/0x70fAB9868cd54E12C7d87196424d6E0ca21be534) |
| **Base Sepolia** | 6 | [`0x8E52a9e76148185536F0f0779749Cc895E5f70dC`](https://base-sepolia.blockscout.com/address/0x8E52a9e76148185536F0f0779749Cc895E5f70dC) |
| **Polygon PoS Amoy** | 7 | [`0x8E52a9e76148185536F0f0779749Cc895E5f70dC`](https://amoy.polygonscan.com/address/0x8E52a9e76148185536F0f0779749Cc895E5f70dC) |
| **Unichain Sepolia** | 10 | [`0x1Fae490d95dDcFFD70728AF5024C524ed303a2e3`](https://unichain-sepolia.blockscout.com/address/0x1Fae490d95dDcFFD70728AF5024C524ed303a2e3) |

## CCTP V1 Interface

This section provides the **CCTP V1 Smart Contract Interface** exposed by **CCTP
V1**, outlining the available functions, and their parameters.

The interface below serves as a reference for permissionless messaging functions
exposed by the **TokenMessenger** and **MessageTransmitter** functions. The full
ABIs are
[available on GitHub](https://github.com/circlefin/evm-cctp-contracts/tree/adb2a382b09ea574f4d18d8af5b6706e8ed9b8f2/docs/abis/cctp).

### TokenMessenger

#### depositForBurn

Deposits and burns tokens from sender to be minted on destination domain. Minted
tokens will be transferred to `mintRecipient`.

**Parameters**

| Field | Type | Description |
| - | - | - |
| `amount` | `uint256` | Amount of tokens to deposit and burn |
| `destinationDomain` | `uint32` | Destination domain identifier |
| `mintRecipient` | `bytes32` | Address of mint recipient on destination domain |
| `burnToken` | `address` | Address of contract to burn deposited tokens on local domain |

#### depositForBurnWithCaller

Same as `depositForBurn` but with an additional parameter, `destinationCaller`.
This parameter specifies which address has permission to call `receiveMessage`
on the destination domain for the message.

**Parameters**

| Field | Type | Description |
| - | - | - |
| `amount` | `uint256` | Amount of tokens to deposit and burn |
| `destinationDomain` | `uint32` | Destination domain identifier |
| `mintRecipient` | `bytes32` | Address of mint recipient on destination domain |
| `burnToken` | `address` | Address of contract to burn deposited tokens on local domain |
| `destinationCaller` | `bytes32` | Address of caller on the destination domain |

#### replaceDepositForBurn

Replace a `BurnMessage` to change the mint recipient and/or destination caller.
Allows the sender of a previous `BurnMessage` (created by `depositForBurn` or
`depositForBurnWithCaller`) to send a new `BurnMessage` to replace the original.
The new `BurnMessage` will reuse the amount and burn token of the original,
without requiring a new deposit.

This is useful in situations where the user specified an incorrect address and
has no way to safely mint the previously burned USDC.

<Note>
  The sender of the original `depositForBurn` has access to call
  `replaceDepositForBurn`. The resulting mint will supersede the original mint,
  as long as the original mint has not confirmed yet onchain. When using a
  third-party app/bridge that integrates with CCTP V1 to burn and mint USDC, it
  is the choice of the app/bridge if and when to replace messages on behalf of
  users. When sending USDC to smart contracts, be aware of the functionality
  that those contracts have and their respective trust model.
</Note>

**Parameters**

| Field | Type | Description |
| - | - | - |
| `originalMessage` | `bytes calldata` | Original message bytes (to replace) |
| `originalAttestation` | `bytes calldata` | Original attestation bytes |
| `newDestinationCaller` | `bytes32` | The new destination caller, which may be the same as the original destination caller, a new destination caller, or an empty destination caller, indicating that any destination caller is valid |
| `newMintRecipient` | `bytes32` | The new mint recipient, which may be the same as the original mint recipient, or different |

### MessageTransmitter

#### receiveMessage

Messages with a given nonce can only be broadcast successfully once for a pair
of domains. The message body of a valid message is passed to the specified
recipient for further processing.

**Parameters**

| Field | Type | Description |
| - | - | - |
| `message` | `bytes calldata` | Message bytes |
| `attestation` | `bytes calldata` | Signed attestation of message |

#### sendMessage

Sends a message to the destination domain and recipient. Emits a `MessageSent`
event which will be attested by Circle's attestation service (Iris).

**Parameters**

| Field | Type | Description |
| - | - | - |
| `destinationDomain` | `uint32` | Destination domain identifier |
| `recipient` | `bytes32` | Address to handle message body on destination domain |
| `messageBody` | `bytes calldata` | App-specific message to be handled by recipient |

#### sendMessageWithCaller

Same as `sendMessage` but with an additional parameter, `destinationCaller`.
This parameter specifies which address has permission to call `receiveMessage`
on the destination domain for the message.

**Parameters**

| Field | Type | Description |
| - | - | - |
| `destinationDomain` | `uint32` | Destination domain identifier |
| `recipient` | `bytes32` | Address of message recipient on destination domain |
| `destinationCaller` | `bytes32` | Address of caller on the destination domain |
| `messageBody` | `bytes calldata` | App-specific message to be handled by recipient |

#### replaceMessage

Replace a message with a new message body and/or destination caller. The
`originalAttestation` must be a valid attestation of `originalMessage`, produced
by Circle's attestation service (Iris).

**Parameters**

| Field | Type | Description |
| - | - | - |
| `originalMessage` | `bytes calldata` | Original message to replace |
| `originalAttestation` | `bytes calldata` | Attestation of `originalMessage` |
| `newMessageBody` | `bytes calldata` | New message body of replaced message |
| `newDestinationCaller` | `bytes32` | The new destination caller, which may be the same as the original destination caller, a new destination caller, or an empty destination caller (bytes32(0), indicating that any destination caller is valid) |