> ## Documentation Index > Fetch the complete documentation index at: https://docs.beinfi.com/llms.txt > Use this file to discover all available pages before exploring further. # Pay an invoice at checkout > Creates a charge on an open invoice using the method the payer picked (`pix`, `boleto`, `card` or `crypto`). The response carries what the payer needs to finish, such as the Pix QR code. Confirmation comes later: poll the payment status or wait for the `payment.confirmed` webhook. ## OpenAPI ````yaml /api-reference/openapi.en.json post /pay/{slug}/invoices/{invoiceID}/charge openapi: 3.1.0 info: title: Infi API version: 0.0.1 description: > The Infi REST API: catalog, customers, usage metering, subscriptions, invoices, payments and checkout. **Authentication.** Send your secret key as `Authorization: Bearer sk_test_…` (sandbox) or `sk_live_…` (production). The key prefix selects the environment. Checkout routes (`/pay/*`) and `/public/*` take no key: they run in the payer's browser. **Idempotency.** Every request that changes data requires an `Idempotency-Key` header. A retry with the same key returns the original response instead of running again. **Amounts.** Money and quantities travel as decimal strings (`"150.00"`, `"0.0001"`), never as floating-point numbers. **Errors.** The body carries `error_code` (stable, branch on it), `message` (for humans) and `tracer_id` (send it to support). Rate-limit and idempotency errors are nested under `error`, with `code` and `request_id`. servers: - url: https://api-sandbox.beinfi.com description: Sandbox - url: https://api.beinfi.com description: Production security: - bearerAuth: [] tags: - name: Catalog - name: Customers - name: Metering - name: Subscriptions - name: Invoices - name: Payments - name: Checkout - name: Coupons - name: Billing - name: Account - name: Webhooks - name: Test account - name: Rail - name: Storefronts paths: /pay/{slug}/invoices/{invoiceID}/charge: post: tags: - Checkout summary: Pay an invoice at checkout description: > Creates a charge on an open invoice using the method the payer picked (`pix`, `boleto`, `card` or `crypto`). The response carries what the payer needs to finish, such as the Pix QR code. Confirmation comes later: poll the payment status or wait for the `payment.confirmed` webhook. operationId: chargeCheckoutInvoice parameters: - name: slug in: path required: true schema: type: string description: Your account's public identifier, as in checkout URLs. - name: invoiceID in: path required: true schema: type: string format: uuid description: Invoice ID. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CheckoutChargeRequest' responses: '201': content: application/json: schema: $ref: '#/components/schemas/Payment' description: The created charge. '400': $ref: '#/components/responses/BadRequest' '404': $ref: '#/components/responses/NotFound' '409': content: application/json: schema: $ref: '#/components/schemas/ConflictError' description: > The invoice is not open (`invoice_not_open`), a charge is already in progress on it (`charge_in_progress`), the previous charge is already being processed and cannot be switched to another method (`charge_already_processing` — wait for it to finish), or the account's card setup is incomplete (`client_key_missing`). '422': content: application/json: schema: $ref: '#/components/schemas/ValidationError' description: > Something the caller can fix. Besides `validation_failed`: `customer_tax_id_required` (Pix and boleto need the payer's CPF/CNPJ) and `amount_below_minimum` (in BRL, a charge under R$ 5.00 may be refused; the minimum that applies to this charge is in `errors[]`, under `amount`; a deep coupon discount can cause this). '429': $ref: '#/components/responses/RateLimited' '502': content: application/json: schema: $ref: '#/components/schemas/Error' description: >- The charge could not be created right now, or the previous attempt could not be released to switch methods. Nothing was charged; retry. '503': $ref: '#/components/responses/ServiceUnavailable' security: [] components: schemas: CheckoutChargeRequest: type: object required: - method properties: method: type: string enum: - pix - boleto - card - crypto description: Payment method. card: $ref: '#/components/schemas/CheckoutCardInput' description: >- Card details. Required when `method` is `card` on an embedded checkout. saveInstrument: type: boolean description: >- The payer chose to save the card for future automatic charges. Requires `consentTextVersion`; without it, returns 422. consentTextVersion: type: string description: >- The version of the authorization text the payer saw: echo `CheckoutSession.mandate.version`. Required with `saveInstrument`. surface: type: string enum: - hosted - embed default: hosted description: >- Which Infi checkout the payer is on. It sets where the browser returns after a bank verification. Use `embed` from an embedded (iframe) checkout; without it, `hosted` applies and the payer leaves the iframe for the full page. description: The method the payer picked. A missing or unknown `method` returns 422. Payment: type: object properties: id: type: string format: uuid invoiceId: type: string format: uuid provider: type: string description: The processor the charge ran through. In sandbox, `sandbox`. providerId: type: - string - 'null' description: The charge's reference at the processor, useful for support. method: type: string enum: - pix - boleto - card - crypto amount: type: string description: Amount charged, as a decimal string. currency: type: string status: type: string enum: - pending - confirmed - failed - refunded - charged_back description: >- `pending` awaits payment; `confirmed` was paid; `failed` was not paid (see `failureCode`); `refunded` was fully refunded; `charged_back` was disputed by the buyer with their bank. refundedAmount: type: string description: >- Total refunded so far, as a decimal string. Absent when nothing was refunded. A partial refund keeps `status` at `confirmed`; only refunding the full amount sets `refunded`. Use this field, not `status`, to know how much went back. failureCode: type: - string - 'null' enum: - insufficient_funds - do_not_honor - card_declined - authentication_required - card_expired - card_stolen - card_invalid - mandate_revoked - mandate_refused - brand_changed - provider_error - provider_timeout - superseded - null description: >- Why the charge failed. `superseded` is not a decline: the buyer switched payment method to pay the same invoice. Null when the payment did not fail or when no reason was recorded. New codes may appear; treat an unknown value as a generic failure. failedAt: type: - string - 'null' format: date-time description: When the charge moved to `failed`. createdAt: type: string format: date-time payer: type: - object - 'null' properties: id: type: string format: uuid name: type: - string - 'null' email: type: - string - 'null' description: >- Who paid. On a one-off invoice, `id` is the customer ID; on a subscription invoice, it is the ID of the customer's enrollment in the product. Present only on `GET /billing/payments` and `GET /billing/payments/{paymentID}`, and null when the invoice does not identify the customer. invoiceUrl: type: string description: Hosted payment page. Present only on the charge-creation response. chargeToken: type: string description: >- Single-use token for the crypto payment widget. Present only on a crypto charge response. network: type: string enum: - main - test description: 'Crypto widget environment for this charge: `main` (real) or `test`.' settlementAsset: type: string enum: - USDC description: Asset the crypto charge settles in. settlementNetwork: type: string enum: - base - solana description: Network the crypto charge settles on. pixPayload: type: string description: >- Pix copy-and-paste code. Render the QR from it. Still available on later reads of the payment. pixQrImage: type: string description: >- The Pix QR as a base64 PNG (no `data:` prefix), if you would rather not render it yourself. providerPixPayload: type: string description: >- Sandbox only: the Pix code the test processor generated, for inspection. Not payable. In sandbox, `pixPayload` carries the test confirmation link. sandboxConfirmUrl: type: string description: >- Sandbox only: a page that marks this charge as paid without real money. Branch on whether this field is present, not on the shape of `pixPayload`. You do not need it to render: `pixPayload` is a QR in both environments. pixExpiresAt: type: - string - 'null' format: date-time description: When the Pix code expires (Pix charges only). clientSecret: type: string description: >- Temporary secret to confirm a card charge in the browser. Present only on the charge-creation response. publishableKey: type: string description: >- Public key paired with `clientSecret`. Present only on the charge-creation response. nextAction: $ref: '#/components/schemas/PaymentNextAction' description: >- Data to complete a card charge in the browser. Present only on the charge-creation response. switchable: type: boolean description: >- Whether this charge can still be dropped so the same invoice is paid another way: `true` while `pending`, `false` once paid or failed. Present only on the charge-creation response; treat a missing value as `false`. description: >- One charge attempt against an invoice. An invoice can have several payments. ConflictError: type: object required: - message - error_code - tracer_id - resource - metadata properties: message: type: string description: Human-readable explanation. error_code: $ref: '#/components/schemas/ErrorCode' description: Stable error code. Branch on this field. tracer_id: type: string description: Request identifier. Send it to support. resource: type: string description: The kind of resource in conflict. Empty string when not applicable. metadata: type: - object - 'null' additionalProperties: type: string description: Conflict details, as key-value pairs. `null` when there are none. description: 'Body of a 409 error: the resource''s state does not allow the operation.' ValidationError: type: object required: - message - error_code - tracer_id - errors properties: message: type: string error_code: $ref: '#/components/schemas/ErrorCode' tracer_id: type: string errors: type: array items: type: object required: - field - value - constraint - description properties: field: type: string value: type: string constraint: type: string description: type: string description: >- Per-field detail (`field`, `description`). Always present on a `422`; may be empty. description: >- Body of a `422`. Same shape as `Error`, plus `errors[]` with per-field detail. That is where the sentence telling you what to fix lives (for example, "product has no published version"). Error: type: object required: - message - error_code - tracer_id properties: message: type: string description: Human-readable sentence. error_code: $ref: '#/components/schemas/ErrorCode' description: Stable error code. Branch on it. tracer_id: type: string description: Request id. Include it when contacting support. description: >- The standard error body. It is flat (no `error` wrapper) and the trace id is `tracer_id`. CheckoutCardInput: type: object required: - number - holderName - expiryMonth - expiryYear - ccv - holderEmail - holderCpfCnpj - holderPostalCode - holderAddressNumber properties: number: type: string holderName: type: string expiryMonth: type: string example: '12' expiryYear: type: string example: '2030' ccv: type: string description: Card security code. holderEmail: type: string format: email holderCpfCnpj: type: string description: Cardholder CPF or CNPJ. holderPostalCode: type: string description: Cardholder postal code. holderAddressNumber: type: string description: Cardholder street number. holderPhone: type: string description: >- Card and holder details for a card charge on an embedded checkout. Sent over a secure connection; the card number and security code are never stored by Infi. All fields are required. PaymentNextAction: oneOf: - $ref: '#/components/schemas/CardSessionAction' - $ref: '#/components/schemas/CardPaymentAction' discriminator: propertyName: type mapping: adyen_session: $ref: '#/components/schemas/CardSessionAction' stripe_payment_intent: $ref: '#/components/schemas/CardPaymentAction' description: >- Temporary data for the browser to complete the charge. Branch on `type`. Use it only in the same session; do not reuse it or accept these values back from the browser. NotFoundError: type: object required: - message - error_code - tracer_id - resource properties: message: type: string error_code: $ref: '#/components/schemas/ErrorCode' tracer_id: type: string resource: type: string ErrorCode: type: string examples: - internal_error - validation_failed - bad_request - unauthorized - forbidden - not_found - conflict - rate_limited description: >- Stable error code. The list is open: besides the generic codes, each area defines its own (`coupon_expired`, `insufficient_balance`, `version_not_draft`, `idempotency_key_reused`…). Handle a code you do not recognize by its HTTP status and show `message`; do not fail parsing the response. RequestError: type: object required: - error properties: error: type: object required: - code - message - request_id properties: code: $ref: '#/components/schemas/ErrorCode' message: type: string request_id: type: string CardSessionAction: type: object additionalProperties: false required: - type - session - clientKey - environment - countryCode - locale - amount properties: type: type: string const: adyen_session session: type: object additionalProperties: false required: - id - sessionData properties: id: type: string sessionData: type: string description: Checkout session to open in the browser. Do not store or log it. clientKey: type: string description: Public key, safe for the browser. environment: type: string enum: - live - live-us - live-au - live-nea - live-in description: Environment the form must load in. countryCode: type: string const: BR locale: type: string const: pt-BR amount: $ref: '#/components/schemas/ClientActionAmount' description: Charge amount. description: Payment session for the in-browser card form. CardPaymentAction: type: object additionalProperties: false required: - type - clientSecret - publishableKey properties: type: type: string const: stripe_payment_intent clientSecret: type: string description: Temporary secret to confirm the charge in the browser. publishableKey: type: string description: Public key, safe for the browser. description: Data to confirm the card charge in the browser. ClientActionAmount: type: object additionalProperties: false required: - value - currency properties: value: type: integer format: int64 minimum: 0 description: Amount in the currency's minor unit (cents, for BRL). currency: type: string example: BRL responses: BadRequest: content: application/json: schema: $ref: '#/components/schemas/Error' description: Malformed request. NotFound: content: application/json: schema: $ref: '#/components/schemas/NotFoundError' description: Resource not found. RateLimited: headers: Retry-After: schema: type: integer content: application/json: schema: $ref: '#/components/schemas/RequestError' description: Rate limit exceeded. `Retry-After` gives the wait in seconds. ServiceUnavailable: content: application/json: schema: $ref: '#/components/schemas/Error' description: Temporarily unavailable. Retry shortly. securitySchemes: bearerAuth: type: http scheme: bearer description: >- Your account's secret key: `Authorization: Bearer sk_test_…` or `sk_live_…`. Server-side only. ````