> ## 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 Noble Cosmos module V1

> Cosmos SDK Module for CCTP V1 support on Noble

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

## Overview

Noble is a Cosmos application-specific blockchain (or "appchain") that provides
native asset issuance for the Cosmos ecosystem. USDC is natively issued on Noble
and can be transferred via the Inter-Blockchain Communication Protocol (IBC) to
other supported appchains in Cosmos, or via CCTP V1 to any supported domain (for
example, Ethereum).

Note that there are key differences between Cosmos appchains like Noble and
EVM-compatible blockchains. Unlike on EVM chains where CCTP V1 is a set of smart
contracts, CCTP V1 on Noble is a Cosmos SDK module, which is deployed by Noble
governance and built into the Noble blockchain. Cosmos appchains can use IBC to
build composable flows with CCTP V1 on Noble.

## Testnet and Mainnet Module Address

| Chain | [Domain](/cctp/v1/supported-domains) | Address |
| :- | :- | :- |
| Noble | 4 | noble12l2w4ugfz4m6dd73yysz477jszqnfughxvkss5 |

CCTP V1 on Noble source code is
[available on GitHub](https://github.com/circlefin/noble-cctp). The full message
spec is defined at
[noble-cctp/x/cctp/spec/02\_messages.md](https://github.com/circlefin/noble-cctp/blob/dc81b3e0d566d195c869a213519fcecd38b020a5/x/cctp/spec/02_messages.md).
The interface below serves as a reference for permissionless messaging functions
exposed by the module.

## Module Interface

### depositForBurn

**Message**: `MsgDepositForBurn`

Broadcast a transaction that deposits for burn to a provided domain.

**Arguments**:

* `Amount` - The burn amount
* `DestinationDomain` - Domain of destination chain
* `MintRecipient` - address receiving minted tokens on destination chain as a 32
  length byte array
* `BurnToken` - The burn token address on source domain

### depositForBurnWithCaller

**Message**:`MsgDepositForBurnWithCaller`

Broadcast a transaction that deposits for burn with caller to a provided domain.

This message wraps `MsgDepositForBurn`. It adds one extra argument,
`destinationCaller`.

**Arguments**:

* `Amount` - The burn amount
* `DestinationDomain` - Domain of destination chain
* `MintRecipient` - address receiving minted tokens on destination chain as a 32
  length byte array
* `BurnToken` - The burn token address on source domain
* `DestinationCaller` - authorized caller as 32 length byte array of
  receiveMessage() on destination domain

### replaceDepositForBurn

**Message**: `MsgReplaceDepositForBurn`

Broadcast a transaction that replaces a deposit for burn message. Replace 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.

**Arguments**:

* `OriginalMessage`- original message bytes to replace
* `OriginalAttestation`- attestation bytes of `OriginalMessage`
* `NewDestinationCaller` - 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` - the new mint recipient. May be the same as the\
  original mint recipient, or different.

### receiveMessage

**Message**: `MsgReceiveMessage`

Broadcast a transaction that receives a provided message from another domain.
After validation, it performs a mint.

**Arguments**:

* `message` [Message format](/cctp/v1/message-format)
* `attestation` - Concatenated 65-byte signature(s) of `message`, in increasing
  order\
  of the attester address recovered from signatures.

### sendMessage

**Message**:`MsgSendMessage`

Broadcast a transaction that sends a message to a provided domain.

**Arguments**:

* `DestinationDomain` - Domain of destination chain
* `Recipient` - Address of message recipient on destination chain
* `MessageBody` - Raw bytes content of message

### sendMessageWithCaller

**Message**:`MsgSendMessageWithCaller`

Broadcast a transaction that sends a message with a caller to a provided domain.

Specifying a Destination caller requires that only the specified caller can call
`receiveMessage()` on destination domain.

This message wraps `SendMessage` It adds one extra argument,
`DestinationCaller`.

**Arguments**:

* `DestinationDomain` - Domain of destination chain
* `Recipient` - Address of message recipient on destination chain
* `MessageBody` - Raw bytes content of message
* `DestinationCaller` - caller on the destination domain, as 32 length byte
  array

### replaceMessage

**Message**: `MsgReplaceMessage`

Broadcast a transaction that replaces a provided message. Replace the message
body and/or destination caller.

**Arguments**:

* `OriginalMessage` - original message bytes to replace
* `OriginalAttestation` - attestation bytes of `OriginalMessage`
* `NewMessageBody` - new message body of replaced message
* `NewDestinationCaller` - 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.