> ## 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. # Create a payout quote > Locks an FX rate, fees, and BFI selection for a fiat payout. Returns a binding quote that must be referenced in `POST /v1/payouts` via `quoteId`. Quotes expire at `expiresAt`. Specify either `from.amount` (exact-in: debit a fixed USDC amount) or `to.amount` (exact-out: deliver a fixed fiat amount). Exactly one must be set. When `to.rail` is omitted, one quote per available live rail is returned. When `to.rail` is specified, only that rail is quoted. ## OpenAPI ````yaml openapi/managed-payments.yaml post /v1/payouts/quotes openapi: 3.0.2 info: version: ${version} title: Managed Payments API description: | The Managed Payments API enables Payment Service Providers (PSPs) to create and manage sub-client accounts for stablecoin settlement, and to send fiat payouts to registered beneficiaries worldwide. servers: - url: https://api-sandbox.circle.com - url: https://api.circle.com security: [] tags: - name: Managed Payments Accounts description: Create and manage sub-client accounts for Managed Payments PSPs. - name: Managed Payments Credit description: Get credit line details and wire instructions for repayment. - name: Managed Payments Credit Transfers description: Create and manage credit transfers (drawdowns) against a credit line. - name: Managed Payments Transfers description: >- Create and manage internal account-to-account transfers for Managed Payments. - name: Managed Payments Fiat Payouts description: > Register and manage fiat payout beneficiaries, discover supported corridors and field requirements, and create locked FX quotes for cross-border fiat payouts. paths: /v1/payouts/quotes: post: tags: - Managed Payments Fiat Payouts summary: Create a payout quote description: > Locks an FX rate, fees, and BFI selection for a fiat payout. Returns a binding quote that must be referenced in `POST /v1/payouts` via `quoteId`. Quotes expire at `expiresAt`. Specify either `from.amount` (exact-in: debit a fixed USDC amount) or `to.amount` (exact-out: deliver a fixed fiat amount). Exactly one must be set. When `to.rail` is omitted, one quote per available live rail is returned. When `to.rail` is specified, only that rail is quoted. operationId: createPayoutQuote requestBody: required: true content: application/json: schema: type: object required: - useCase - from - to properties: useCase: type: string enum: - B2B - B2C - C2B - C2C description: > Use case that describes the originator and recipient relationship. - `B2B` — business originator, business recipient. - `B2C` — business originator, individual recipient. - `C2B` — individual originator, business recipient. - `C2C` — individual originator, individual recipient. from: type: object required: - currency properties: walletId: type: string description: > Circle wallet to debit. Omit to use the entity's master wallet; the response echoes the actual wallet selected. example: '1000000001' currency: type: string enum: - USDC description: >- Source cryptocurrency. Only `USDC` is currently supported. example: USDC amount: type: string description: | Exact-in: debit this amount from the source wallet. Mutually exclusive with `to.amount`. example: '95.50' to: type: object required: - currency - country properties: currency: type: string description: Destination fiat currency code. example: MXN country: type: string description: ISO 3166-1 alpha-2 destination country code. example: MX rail: type: string description: > Payment rail. When omitted, all available rails for the corridor are quoted. example: SPEI amount: type: string description: | Exact-out: deliver this amount to the beneficiary. Mutually exclusive with `from.amount`. example: '1800.00' examples: Exact-out B2C MXN SPEI: value: useCase: B2C from: walletId: '1000000001' currency: USDC to: currency: MXN amount: '1800.00' country: MX rail: SPEI responses: '200': description: > Quote(s) locked. Returns an array — one element per rail when `to.rail` is omitted, one element when `to.rail` is specified. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: type: object properties: data: type: array items: type: object required: - id - type - useCase - pair - from - to - rate - fees - expiresAt properties: id: type: string format: uuid description: >- Quote identifier. Pass as `quoteId` in `POST /v1/payouts`. example: 66666666-7777-8888-9999-000000000000 type: type: string enum: - tradable - reference description: >- Quote type. `tradable` is a binding, executable quote; `reference` is indicative only and cannot be used to create a payout. useCase: type: string description: Echoed from request. pair: type: string description: Currency pair (e.g. `USDC_MXN`). example: USDC_MXN from: type: object properties: walletId: type: string description: Actual wallet selected (echoed or defaulted). currency: type: string amount: type: string description: Computed source amount. chain: type: string description: Funding chain selected by the system. to: type: object properties: currency: type: string amount: type: string description: Computed destination amount. country: type: string rail: type: string rate: type: string description: >- Locked FX rate (source currency per destination currency unit). example: '18.848' fees: type: array description: Aggregated fees deducted from the source amount. items: type: object properties: type: type: string enum: - FIAT_PAYOUT_FEE amount: type: string currency: type: string expiresAt: type: string format: date-time description: ISO 8601 timestamp when this quote expires. examples: Quote response: value: data: - id: 66666666-7777-8888-9999-000000000000 type: tradable useCase: B2C pair: USDC_MXN from: walletId: '1000000001' currency: USDC amount: '95.50' chain: MATIC to: currency: MXN amount: '1800.00' country: MX rail: SPEI rate: '18.848' fees: - type: FIAT_PAYOUT_FEE amount: '1.35' currency: USDC expiresAt: '2026-08-12T00:15:00Z' '400': description: Invalid request or corridor/rail not available. '401': description: Unauthorized. security: - bearerAuth: [] components: headers: XRequestId: description: >- Universally unique identifier (UUID v4) for the request. Helpful for identifying a request when communicating with Circle support. schema: type: string format: uuid example: 2adba88e-9d63-44bc-b975-9b6ae3440dde securitySchemes: bearerAuth: type: http scheme: bearer ````