> ## 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 PIX bank account ## OpenAPI ````yaml openapi/account.yaml post /v1/businessAccount/banks/pix openapi: 3.0.2 info: version: ${version} title: Core Functionality description: > All of Circle's APIs share a common set of core functionality that lets you manage your Circle Account in a programmatic way. With a Circle Account your business can deposit traditional money from 80+ countries and seamlessly convert them into "digital currency dollars": USDC. You can then use USDC for everyday payments and treasury flows. servers: - url: https://api-sandbox.circle.com - url: https://api.circle.com security: [] tags: - name: Balances description: Get information on settled and unsettled balances. - name: Payouts description: Create and get information on 1st party payouts. - name: Wires description: >- Create, get instructions, and get information on 1st party bank accounts for wire transfers. - name: CUBIX description: Create and get information on CUBIX accounts. - name: PIX description: Create and get information on PIX accounts. - name: Transfers description: Create and get information on 1st party transfers. - name: Addresses description: Generate and get information on blockchain addresses. - name: Deposits description: Get information on 1st party deposits. - name: Payments description: Create, cancel, refund, and get updates on card payments. - name: Settlement Bank Routing description: View and manage settlement bank routing preferences for fiat accounts. - name: Reporting description: >- Retrieve transaction and balance reports, including ISO 20022 (CAMT.053) statements and managed-payment reports. paths: /v1/businessAccount/banks/pix: post: tags: - PIX summary: Create a PIX bank account operationId: createBusinessPixAccount requestBody: content: application/json: schema: $ref: '#/components/schemas/PixFiatAccountCreationRequest' responses: '201': description: Successfully created a bank account for PIX transfers. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: title: CreateBusinessPixAccountResponse properties: data: $ref: '#/components/schemas/PixFiatAccountResponse' examples: response: value: data: id: b8627ae8-732b-4d25-b947-1df8f4007a29 status: pending description: BTG Pactual ****0010 trackingRef: CIR13FB13A transferTypesInfo: pix: currencies: - BRL riskEvaluation: decision: approved reason: '3000' policyEvaluation: status: approved fingerprint: eb170539-9e1c-4e92-bf4f-1d09534fdca2 createDate: '2020-04-10T02:13:30.000Z' updateDate: '2020-04-10T02:13:30.000Z' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/NotAuthorized' security: - bearerAuth: [] components: schemas: PixFiatAccountCreationRequest: type: object required: - idempotencyKey - name - accountNumber - ispb - branchCode - taxId - accountType properties: idempotencyKey: $ref: '#/components/schemas/IdempotencyKey' name: type: string description: Name of the beneficiary. example: CIRCLE INTERNET FINANCIAL INC accountNumber: type: string description: Beneficiary account number. example: '322286803' ispb: type: string description: Beneficiary ISPB. example: '68033222' branchCode: type: string description: Beneficiary account branch code. example: '123' taxId: type: string description: Beneficiary Tax ID. example: '57112345675712' accountType: $ref: '#/components/schemas/PixAccountType' PixFiatAccountResponse: type: object required: - id - status - description - trackingRef - fingerprint - createDate - updateDate - transferTypesInfo properties: id: $ref: '#/components/schemas/Id' status: $ref: '#/components/schemas/ExternalFiatAccountStatus' description: type: string description: Bank name plus last four digits of the PIX account number. example: BTG Pactual ****0010 trackingRef: type: string description: >- Wire tracking ref that needs to be set in the wire reference to beneficiary field. example: CIR13FB13A transferTypesInfo: type: object description: >- A map which shows transfer types supported on this account as well as additional information for each. For PIX accounts this will always only show information for PIX transfers. additionalProperties: $ref: '#/components/schemas/TransferTypeInfo' example: pix: currencies: - BRL riskEvaluation: $ref: '#/components/schemas/RiskEvaluation' policyEvaluation: $ref: '#/components/schemas/PolicyEvaluation' fingerprint: $ref: '#/components/schemas/Fingerprint' createDate: $ref: '#/components/schemas/UtcTimestamp' updateDate: $ref: '#/components/schemas/UtcTimestamp' IdempotencyKey: type: string description: >- Universally unique identifier (UUID v4) idempotency key. This key is utilized to ensure exactly-once execution of mutating requests. format: uuid example: ba943ff1-ca16-49b2-ba55-1057e70ca5c7 PixAccountType: type: string title: Account type description: Beneficiary account type. enum: - checking - savings - salary - prepaid example: checking Id: type: string description: Unique system generated identifier for the entity. format: uuid example: b8627ae8-732b-4d25-b947-1df8f4007a29 ExternalFiatAccountStatus: description: >- Status of the account. A `pending` status indicates that the linking is in-progress; `complete` indicates the account was linked successfully; `failed` indicates it failed. type: string enum: - pending - complete - failed TransferTypeInfo: type: object required: - currencies description: Additional information for specific transfer type. properties: currencies: type: array uniqueItems: true items: $ref: '#/components/schemas/FiatCurrency' additionalProperties: description: Additional properties that apply to specific transfer type. type: object properties: transactionLimits: type: integer description: Transaction amount limit for the transfer type. example: 100000 RiskEvaluation: type: object description: >- Results of risk evaluation. Present when the payment's risk decision is `denied` or `review`. Absent when `decision` is `approved` or when no risk evaluation was performed. nullable: true properties: decision: description: Enumerated decision of the account. type: string enum: - approved - denied - review reason: description: >- Risk reason code for the decision. Known values include `3000` (transaction involves a sanctioned or unsupported wallet) and `2151` (transaction denied on outbound compliance screening; a failed refund, for example). Present when `decision` is `denied`; may be omitted for `review` decisions. type: string nullable: true example: '3000' PolicyEvaluation: type: object description: >- Results of policy evaluation. Only present if a policy decision has been recorded. nullable: true required: - status properties: status: description: Status of the policy evaluation. type: string enum: - approved - pending - rejected - expired - cancelled - failed example: approved Fingerprint: type: string description: >- A UUID that uniquely identifies the account number. If the same account is used more than once, each card object will have a different id, but the fingerprint will stay the same. example: eb170539-9e1c-4e92-bf4f-1d09534fdca2 UtcTimestamp: type: string description: ISO-8601 UTC date/time format. example: '2020-04-10T02:13:30.000Z' FiatCurrency: type: string description: Currency code. title: Currency enum: - USD - EUR - MXN - SGD - BRL 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 responses: BadRequest: description: The request cannot be processed due to a client error. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: type: object title: BadRequest required: - code - message properties: code: type: integer example: 400 message: type: string example: Something went wrong. example: code: 400 message: Bad request. examples: response: value: code: 400 message: Bad request. NotAuthorized: description: >- The request has not been applied because it lacks valid authentication credentials. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: type: object title: NotAuthorized required: - code - message properties: code: type: integer example: 400 message: type: string example: Something went wrong. example: code: 401 message: Malformed authorization. examples: response: value: code: 401 message: Malformed authorization. securitySchemes: bearerAuth: type: http scheme: bearer ````