> ## 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. # How minting and redemption works > Understand how Circle Mint converts fiat to USDC (minting) and USDC back to fiat (redemption), including settlement timing, account structure, and compliance requirements. Circle Mint's core operations are minting and redemption. Minting converts fiat currency into stablecoins (USDC or EURC), and redemption converts stablecoins back to fiat. Every token mints and redeems at a 1:1 ratio with the underlying fiat currency. This page explains the mental model behind these operations, including settlement timing, account structure, onchain transfers, fees, and compliance. ## Minting Minting (also known as an onramp) is the process of depositing fiat currency and receiving an equivalent amount of stablecoins. When you send a fiat transfer to Circle, Circle credits your Mint account balance with the corresponding stablecoin amount at a 1:1 ratio. The minting flow works as follows: 1. You initiate a fiat transfer from your linked bank account to Circle. 2. Circle receives the fiat deposit and credits your Mint account balance. 3. The stablecoins become available for onchain transfers or other operations. Circle supports multiple payment rails for fiat deposits, including standard wires (FedWire and SWIFT), real-time interbank rails (RTP, SPEI, SEPA, and CHATS) in supported regions, and book transfers when you bank with one of Circle's settlement partners. Rail availability depends on your region and the currency you are depositing. **Settlement timing:** Domestic wire deposits received before the daily cutoff settle on the same business day. Real-time interbank rails settle in seconds, subject to network operating hours and transaction limits. International wires take 1-3 business days depending on intermediary banks. In the sandbox environment, mock wire deposits process in batches and may take up to 15 minutes. For step-by-step instructions, see [Deposit Fiat](/circle-mint/howtos/deposit-fiat). ## Redemption Redemption (also known as an offramp) is the reverse of minting. You convert stablecoins back to fiat currency by creating a payout to a linked bank account. The redemption flow works as follows: 1. You create a payout request specifying the amount and destination bank account. 2. Circle debits the stablecoin amount from your Mint account balance. 3. Circle sends a fiat transfer to your bank account using the appropriate rail for your region and bank. **Settlement timing:** Payouts typically settle on the next business day. In some cases, your bank may reject the incoming wire, resulting in a returned withdrawal. If a payout is returned, the funds are credited back to your Mint account balance. For step-by-step instructions, see [Withdraw Fiat](/circle-mint/howtos/withdraw-fiat). ## Account structure Your Circle Mint account has several key components that work together to support minting, redemption, and onchain transfers. ### Primary wallet Every Circle Mint account has a primary wallet identified by a `masterWalletId`. You retrieve this identifier from the `/v1/configuration` endpoint. The primary wallet serves as the source for outbound transfers and the destination for inbound deposits. ### Balances Your account maintains two types of balances: * **Available balance:** Settled funds you can transfer or redeem immediately. * **Unsettled balance:** Funds that are in transit and not yet available. Wire deposits appear as unsettled until they clear. ### Linked bank accounts You register external bank accounts to send and receive fiat. Each linked bank account receives a unique Virtual Account Number (VAN). When you wire funds to Circle using the VAN, Circle attributes the deposit to your account without requiring a tracking reference in the payment instruction. ### Deposit addresses Circle generates one deposit address per blockchain for your account. These addresses receive inbound stablecoin transfers from external wallets. You retrieve your deposit addresses through the API for each [supported blockchain](/circle-mint/references/supported-chains-and-currencies). ### Recipient addresses Recipient addresses are external blockchain addresses that you register and allowlist for outbound transfers. You must create a recipient address before you can send stablecoins to it. This allowlisting step provides an additional layer of security for outbound transfers. ## Onchain transfers Circle Mint supports both receiving and sending stablecoins onchain. * **Receiving:** External wallets send USDC or EURC to your deposit address on any supported blockchain. Circle detects the transfer and credits your account after the required number of [blockchain confirmations](/circle-mint/references/blockchain-confirmations). * **Sending:** You create a transfer to a registered recipient address. Circle debits your balance and broadcasts the transaction onchain. ### Transfer status lifecycle Onchain transfers progress through the following statuses: | Status | Description | | - | - | | `pending` | The transfer request is created but not yet broadcast onchain. | | `running` | The transaction is broadcast and awaiting blockchain confirmations. | | `complete` | The required confirmations are reached and the transfer is final. | For details on confirmation requirements per blockchain, see [Blockchain confirmations](/circle-mint/references/blockchain-confirmations). For step-by-step transfer instructions, see [Transfer USDC Onchain](/circle-mint/howtos/transfer-on-chain). ## Network fees Circle covers gas fees for outbound stablecoin transfers in most cases. You do not need to hold the native token of each blockchain to send USDC or EURC from your Mint account. ## Travel Rule compliance Transfers of \$3,000 or more in value on supported blockchains are subject to the FinCEN Travel Rule, which requires identity data about the originator of the transaction. How Circle handles the identity requirement depends on the type of transfer: * **Business account transfers:** Circle uses your company's identity stored on file. You do not need to include identity data in each request. * **Third-party payouts:** If you send funds on behalf of someone else, you must provide the originator's identity (name and address) in the payout request. Omitting required identity data causes the transfer to fail. For the full list of supported blockchains and implementation details, see [Travel Rule compliance](/circle-mint/howtos/transfer-on-chain#travel-rule-compliance). ## Approval workflows Customers in France and Singapore are subject to additional recipient address verification requirements. Before an outbound transfer can proceed, the recipient address must be verified through the [Mint Console](https://app.circle.com/signin). This approval step ensures compliance with local regulatory requirements in those jurisdictions.