openapi: 3.2.0
info:
  title: Bilt Checkout SDK One-time payments API
  version: 0.2.0-draft
  description: '# Introduction


    External backend contract for integrators using the Bilt Checkout SDK.'
servers:
- url: https://partnerapi.biltrewards.com
  description: Production — partner (third-party) gateway
- url: https://staging.partnerapi.biltrewards.com
  description: Staging — partner (third-party) gateway
security:
- checkoutPartnerOAuth: []
tags:
- name: One-Time Payments
  description: 'Open a checkout session that renders Bilt-hosted checkout in the

    Checkout SDK. The customer confirms the payment themselves; the

    outcome arrives as a `checkout.session.*` webhook.'
paths:
  /partner/checkout/v1/checkout-sessions:
    post:
      tags:
      - One-Time Payments
      summary: Create a one-time payment checkout session
      operationId: createCheckoutSession
      description: 'Creates a hosted checkout session for one order and returns a

        short-lived `checkoutUrl` to present in the Checkout SDK. Bilt

        resolves `integratorCustomerId` to the linked Bilt member and renders

        their payment methods, eligible credits, and the order summary inside

        the hosted checkout — your app renders none of this.


        The session stays `OPEN` until the customer pays, abandons it, or it

        reaches `expiresAt`; each of those outcomes is delivered as a

        `checkout.session.*` webhook. Session TTL is configured per

        integrator during onboarding.


        `201` means the session exists. It does not mean the customer has

        paid — wait for `checkout.session.completed`.'
      parameters:
      - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreatePaymentRequest'
            example:
              integratorCustomerId: acme_customer_sandbox_123
              orderId: acme_order_sandbox_456
              lineItems:
              - integratorSkuId: acme_membership_monthly
                lineItemType: PRODUCT
                quantity: 1
                unitPriceCents: 4900
                amountCents: 4900
                currency: USD
              metadata:
                correlationId: acme_correlation_sandbox_789
      responses:
        '201':
          description: Checkout session created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CheckoutSessionEnvelope'
              example:
                data:
                  sessionId: checkout_session_sandbox_123
                  mode: hosted
                  status: OPEN
                  orderId: acme_order_sandbox_456
                  amounts:
                    subtotalCents: 4900
                    currency: USD
                  checkoutUrl: https://checkout.sandbox.example.invalid/s/session_sandbox_token
                  expiresAt: '2026-08-24T22:30:00Z'
        '400':
          $ref: '#/components/responses/InvalidRequest'
        '401':
          $ref: '#/components/responses/Unauthenticated'
        '404':
          $ref: '#/components/responses/CustomerNotFound'
        '409':
          $ref: '#/components/responses/Conflict'
        '429':
          $ref: '#/components/responses/RateLimited'
        '500':
          $ref: '#/components/responses/InternalError'
        '503':
          $ref: '#/components/responses/ServiceUnavailable'
      callbacks:
        checkoutSessionCompleted:
          https://acme.example.invalid/webhooks/bilt:
            post:
              tags:
              - Payment webhooks
              summary: checkout.session.completed
              operationId: onCheckoutSessionCompleted
              security: []
              parameters:
              - $ref: '#/components/parameters/WebhookId'
              - $ref: '#/components/parameters/WebhookTimestamp'
              - $ref: '#/components/parameters/WebhookSignature'
              requestBody:
                required: true
                content:
                  application/json:
                    schema:
                      $ref: '#/components/schemas/PaymentWebhookEvent'
                    example:
                      type: checkout.session.completed
                      timestamp: '2026-08-24T22:15:12.344Z'
                      data:
                        sessionId: checkout_session_sandbox_123
                        mode: hosted
                        orderId: acme_order_sandbox_456
                        integratorCustomerId: acme_customer_sandbox_123
                        status: COMPLETED
                        paymentId: payment_sandbox_789
                        amounts:
                          subtotalCents: 4900
                          creditsAppliedCents: 500
                          chargedAmountCents: 4400
                          currency: USD
              responses:
                2xx:
                  description: Event acknowledged; Bilt will not redeliver it.
        checkoutSessionCancelledOrExpired:
          https://acme.example.invalid/webhooks/bilt:
            post:
              tags:
              - Payment webhooks
              summary: checkout.session.cancelled / checkout.session.expired
              operationId: onCheckoutSessionEnded
              security: []
              parameters:
              - $ref: '#/components/parameters/WebhookId'
              - $ref: '#/components/parameters/WebhookTimestamp'
              - $ref: '#/components/parameters/WebhookSignature'
              requestBody:
                required: true
                content:
                  application/json:
                    schema:
                      $ref: '#/components/schemas/PaymentWebhookEvent'
                    examples:
                      cancelled:
                        value:
                          type: checkout.session.cancelled
                          timestamp: '2026-08-24T22:20:00.000Z'
                          data:
                            sessionId: checkout_session_sandbox_123
                            mode: hosted
                            orderId: acme_order_sandbox_456
                            integratorCustomerId: acme_customer_sandbox_123
                            status: CANCELLED
                      expired:
                        value:
                          type: checkout.session.expired
                          timestamp: '2026-08-24T22:30:00.000Z'
                          data:
                            sessionId: checkout_session_sandbox_123
                            mode: hosted
                            orderId: acme_order_sandbox_456
                            integratorCustomerId: acme_customer_sandbox_123
                            status: EXPIRED
              responses:
                2xx:
                  description: Event acknowledged; Bilt will not redeliver it.
components:
  parameters:
    WebhookId:
      name: webhook-id
      in: header
      required: true
      description: 'Unique message id, stable across redeliveries of the same event.

        Deduplicate on it.

        '
      schema:
        type: string
        example: msg_2KWPBgLlAfxdpx2AI54pPJ85f4W
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: false
      description: 'Optional but strongly recommended — required in practice for headless

        payments. Any string up to 255 characters; a fresh UUID per attempt

        is the recommended form. A retry with the same key and body returns

        the original result; the same key with a different body is rejected

        with `409 IDEMPOTENCY_CONFLICT`. Keys are scoped to your client.

        '
      schema:
        type: string
        minLength: 1
        maxLength: 255
        example: 6f6b1afd-22e0-4137-a096-b15e41cdc890
    WebhookSignature:
      name: webhook-signature
      in: header
      required: true
      description: 'Space-separated `v1,<base64>` signatures, each the base64

        `HMAC-SHA256` of `"{webhook-id}.{webhook-timestamp}.{rawBody}"`

        keyed by your `whsec_` signing secret. Accept the delivery if any one

        verifies (constant-time comparison). Multiple entries appear only

        during a secret rotation.

        '
      schema:
        type: string
        example: v1,K5oZfzN95Z9UVu1EsfQmfVNQhnkZ2pj9o9NDN/H/pI4=
    WebhookTimestamp:
      name: webhook-timestamp
      in: header
      required: true
      description: 'Unix timestamp in seconds of this delivery attempt. Reject deliveries

        more than 5 minutes from your clock.

        '
      schema:
        type: integer
        format: int64
        example: 1787609712
  schemas:
    PaymentWebhookEvent:
      description: 'Standard Webhooks payload. `type` is the discriminator: each event

        type fixes `data.mode` and `data.status` and states exactly which

        fields are present, so a validator generated from this document

        rejects e.g. `payment.failed` without `failure` or `payment.succeeded`

        without settled `amounts`.

        '
      oneOf:
      - $ref: '#/components/schemas/CheckoutSessionCompletedEvent'
      - $ref: '#/components/schemas/CheckoutSessionCancelledEvent'
      - $ref: '#/components/schemas/CheckoutSessionExpiredEvent'
      - $ref: '#/components/schemas/PaymentSucceededEvent'
      - $ref: '#/components/schemas/PaymentFailedEvent'
      discriminator:
        propertyName: type
        mapping:
          checkout.session.completed: '#/components/schemas/CheckoutSessionCompletedEvent'
          checkout.session.cancelled: '#/components/schemas/CheckoutSessionCancelledEvent'
          checkout.session.expired: '#/components/schemas/CheckoutSessionExpiredEvent'
          payment.succeeded: '#/components/schemas/PaymentSucceededEvent'
          payment.failed: '#/components/schemas/PaymentFailedEvent'
    CheckoutSessionCompletedEvent:
      allOf:
      - $ref: '#/components/schemas/WebhookEventBase'
      - type: object
        properties:
          type:
            type: string
            enum:
            - checkout.session.completed
          data:
            allOf:
            - $ref: '#/components/schemas/WebhookDataBase'
            - type: object
              required:
              - paymentId
              - amounts
              properties:
                mode:
                  type: string
                  enum:
                  - hosted
                status:
                  type: string
                  enum:
                  - COMPLETED
                paymentId:
                  type: string
                  description: Opaque Bilt payment identifier.
                  example: payment_sandbox_789
                amounts:
                  $ref: '#/components/schemas/PaymentAmounts'
    WebhookEventBase:
      type: object
      required:
      - type
      - timestamp
      - data
      properties:
        type:
          type: string
          description: Event type; see **Introduction › Webhooks › Payload**.
        timestamp:
          type: string
          format: date-time
          description: When the event occurred (not when it was delivered).
          example: '2026-08-24T22:15:12.344Z'
    WebhookDataBase:
      type: object
      required:
      - sessionId
      - mode
      - orderId
      - integratorCustomerId
      - status
      properties:
        sessionId:
          type: string
          description: The `sessionId` returned when the session or payment was created.
          example: checkout_session_sandbox_123
        orderId:
          type: string
          description: Your `orderId`, echoed unchanged.
          example: acme_order_sandbox_456
        integratorCustomerId:
          type: string
          description: Your customer identifier, echoed unchanged.
          example: acme_customer_sandbox_123
        metadata:
          $ref: '#/components/schemas/IntegratorMetadata'
    IntegratorMetadata:
      type:
      - object
      - 'null'
      maxProperties: 20
      additionalProperties:
        type: string
        maxLength: 500
      description: 'Optional integrator-owned correlation values (up to 20 keys, string

        values up to 500 characters). Echoed back on webhooks and never

        interpreted by Bilt. Do not include secrets, credentials, card data,

        or personal data.

        '
      example:
        correlationId: acme_correlation_sandbox_789
    ExternalLineItem:
      type: object
      additionalProperties: false
      required:
      - integratorSkuId
      - lineItemType
      - quantity
      - unitPriceCents
      - amountCents
      - currency
      properties:
        integratorSkuId:
          type: string
          minLength: 1
          maxLength: 255
          description: 'Your identifier for the SKU; Bilt maps it to its catalog. Unique

            within one request. [CHECK: the current implementation accepts this

            field as `integratorSku`; rename pending.]

            '
          example: acme_membership_monthly
        lineItemType:
          type: string
          enum:
          - PRODUCT
          description: 'Kind of line. `PRODUCT` today. [CHECK: `SHIPPING`,

            `SUBSCRIPTION`, `INCIDENTAL` are under discussion and not yet

            accepted.]

            '
          example: PRODUCT
        quantity:
          type: integer
          minimum: 1
          example: 1
        unitPriceCents:
          type: integer
          format: int64
          minimum: 0
          description: 'Price per unit in minor currency units. May be `0` for a bundled

            or promotional line; never negative — a discount is not a line

            item.

            '
          example: 4900
        amountCents:
          type: integer
          format: int64
          minimum: 0
          description: 'Line total in minor units; must equal `quantity × unitPriceCents`

            or the request is rejected with `400 INVALID_REQUEST`.

            '
          example: 4900
        currency:
          type: string
          pattern: ^[A-Z]{3}$
          description: ISO 4217 currency code. Currently only `USD` is accepted.
          example: USD
    PaymentFailure:
      type: object
      additionalProperties: false
      description: Why a headless charge could not be completed.
      required:
      - code
      - message
      - retryable
      properties:
        code:
          type: string
          pattern: ^[A-Z][A-Z0-9_]*$
          description: 'Stable reason code. `CARD_DECLINED`, `PAYMENT_METHOD_EXPIRED`,

            `PAYMENT_METHOD_NOT_FOUND`, `PROCESSOR_UNAVAILABLE`.

            [CHECK: final failure-code list is owned by the payment

            processor integration.]

            '
          example: CARD_DECLINED
        message:
          type: string
          description: Human-readable reason; do not branch on it.
          example: The card issuer declined the charge
        retryable:
          type: boolean
          description: 'Whether a **new** headless payment for the same order may

            succeed without the customer acting first (for example a

            transient processor failure). `false` means the customer needs

            to update their payment method in the Bilt app.

            '
          example: true
    PaymentAmounts:
      type: object
      required:
      - subtotalCents
      - creditsAppliedCents
      - chargedAmountCents
      - currency
      description: 'Split of the order total between eligible Bilt credits and the

        customer''s card. `subtotalCents = creditsAppliedCents +

        chargedAmountCents`. On a `202` acceptance `creditsAppliedCents` is

        `0`; the final split is on the `payment.succeeded` webhook. A

        synchronous `200` response carries the final split.

        '
      properties:
        subtotalCents:
          type: integer
          format: int64
          minimum: 0
          description: Sum of `amountCents` over all line items.
          example: 4900
        creditsAppliedCents:
          type: integer
          format: int64
          minimum: 0
          description: Eligible Bilt credits applied automatically.
          example: 500
        chargedAmountCents:
          type: integer
          format: int64
          minimum: 0
          description: Amount charged to the customer's payment method.
          example: 4400
        currency:
          type: string
          pattern: ^[A-Z]{3}$
          example: USD
    CheckoutSession:
      type: object
      required:
      - sessionId
      - mode
      - status
      - orderId
      - amounts
      - checkoutUrl
      - expiresAt
      properties:
        sessionId:
          type: string
          description: Opaque Bilt checkout-session identifier; echoed on webhooks.
          example: checkout_session_sandbox_123
        mode:
          type: string
          enum:
          - hosted
        status:
          type: string
          enum:
          - OPEN
          description: 'Always `OPEN` on creation. Terminal states (`COMPLETED`,

            `CANCELLED`, `EXPIRED`) are delivered by webhook.

            '
        orderId:
          type: string
          description: Your `orderId`, echoed unchanged.
          example: acme_order_sandbox_456
        amounts:
          description: 'Order total as submitted. Credits are chosen by the customer

            inside the hosted checkout, so the final split arrives on

            `checkout.session.completed`.

            '
          $ref: '#/components/schemas/OrderAmounts'
        checkoutUrl:
          type: string
          format: uri
          description: 'Short-lived handoff URL to present in the Checkout SDK. Treat it

            as a bearer credential for this one session.

            '
          example: https://checkout.sandbox.example.invalid/s/session_sandbox_token
        expiresAt:
          type: string
          format: date-time
          description: When the session and its `checkoutUrl` stop working.
          example: '2026-08-24T22:30:00Z'
    PaymentSucceededEvent:
      allOf:
      - $ref: '#/components/schemas/WebhookEventBase'
      - type: object
        properties:
          type:
            type: string
            enum:
            - payment.succeeded
          data:
            allOf:
            - $ref: '#/components/schemas/WebhookDataBase'
            - type: object
              required:
              - paymentId
              - amounts
              properties:
                mode:
                  type: string
                  enum:
                  - headless
                status:
                  type: string
                  enum:
                  - SUCCEEDED
                paymentId:
                  type: string
                  description: Opaque Bilt payment identifier.
                  example: payment_sandbox_790
                amounts:
                  $ref: '#/components/schemas/PaymentAmounts'
    CheckoutSessionCancelledEvent:
      allOf:
      - $ref: '#/components/schemas/WebhookEventBase'
      - type: object
        properties:
          type:
            type: string
            enum:
            - checkout.session.cancelled
          data:
            allOf:
            - $ref: '#/components/schemas/WebhookDataBase'
            - type: object
              properties:
                mode:
                  type: string
                  enum:
                  - hosted
                status:
                  type: string
                  enum:
                  - CANCELLED
    ErrorResponse:
      type: object
      additionalProperties: false
      required:
      - error
      description: 'Error envelope returned on every non-`2xx` response. Branch on the

        stable `code`, not the human-readable `message`.

        '
      properties:
        error:
          $ref: '#/components/schemas/ErrorDetail'
    CheckoutSessionExpiredEvent:
      allOf:
      - $ref: '#/components/schemas/WebhookEventBase'
      - type: object
        properties:
          type:
            type: string
            enum:
            - checkout.session.expired
          data:
            allOf:
            - $ref: '#/components/schemas/WebhookDataBase'
            - type: object
              properties:
                mode:
                  type: string
                  enum:
                  - hosted
                status:
                  type: string
                  enum:
                  - EXPIRED
    PaymentFailedEvent:
      allOf:
      - $ref: '#/components/schemas/WebhookEventBase'
      - type: object
        properties:
          type:
            type: string
            enum:
            - payment.failed
          data:
            allOf:
            - $ref: '#/components/schemas/WebhookDataBase'
            - type: object
              required:
              - failure
              properties:
                mode:
                  type: string
                  enum:
                  - headless
                status:
                  type: string
                  enum:
                  - FAILED
                failure:
                  $ref: '#/components/schemas/PaymentFailure'
    OrderAmounts:
      type: object
      required:
      - subtotalCents
      - currency
      properties:
        subtotalCents:
          type: integer
          format: int64
          minimum: 0
          description: Sum of `amountCents` over all line items.
          example: 4900
        currency:
          type: string
          pattern: ^[A-Z]{3}$
          example: USD
    ErrorDetail:
      type: object
      additionalProperties: false
      required:
      - code
      - message
      - requestId
      - retryable
      properties:
        code:
          type: string
          pattern: ^[A-Z][A-Z0-9_]*$
          description: Stable machine-readable code; see **Introduction › Errors**.
          enum:
          - INVALID_REQUEST
          - UNAUTHENTICATED
          - CUSTOMER_NOT_FOUND
          - PAYMENT_METHOD_NOT_FOUND
          - IDEMPOTENCY_CONFLICT
          - SESSION_ALREADY_COMPLETED
          - RATE_LIMIT_EXCEEDED
          - INTERNAL_ERROR
          - PAYMENT_UNAVAILABLE
          example: CUSTOMER_NOT_FOUND
        message:
          type: string
          description: Human-readable operational message; do not branch on it.
          example: No linked Bilt member for integratorCustomerId
        requestId:
          type: string
          description: Correlation id to quote when contacting Bilt.
          example: request_sandbox_123
        retryable:
          type: boolean
          description: 'Whether sending the same request again may succeed. `false`

            whenever somebody has to act first.

            '
          example: false
    CreatePaymentRequest:
      type: object
      additionalProperties: false
      description: 'Shared request body for one-time payment sessions and headless

        payments. Unknown properties are rejected with `400 INVALID_REQUEST`.

        '
      required:
      - integratorCustomerId
      - orderId
      - lineItems
      properties:
        integratorCustomerId:
          type: string
          minLength: 1
          maxLength: 64
          pattern: ^[A-Za-z0-9_.:~-]+$
          description: 'Your stable identifier for the customer — the same key you use

            for account linking. Bilt resolves it to the linked Bilt member.

            Never send a Bilt member id.

            '
          example: acme_customer_sandbox_123
        orderId:
          type: string
          minLength: 1
          maxLength: 255
          pattern: ^[A-Za-z0-9_.:~-]+$
          description: 'Your identifier for this order, invoice, or payment attempt. It

            must exist on your side before you call this endpoint — Bilt only

            stores and echoes it, unchanged, on the response and on every

            webhook for this payment. If your order record is created only

            after payment, generate the id first and attach the order to it

            when the webhook arrives.

            '
          example: acme_order_sandbox_456
        lineItems:
          type: array
          minItems: 1
          maxItems: 100
          description: 'Sealed list of what is being paid for. All items must share one

            `currency`, and `integratorSkuId` must be unique within the request.

            '
          items:
            $ref: '#/components/schemas/ExternalLineItem'
        metadata:
          $ref: '#/components/schemas/IntegratorMetadata'
    CheckoutSessionEnvelope:
      type: object
      required:
      - data
      properties:
        data:
          $ref: '#/components/schemas/CheckoutSession'
  responses:
    InvalidRequest:
      description: 'The request is malformed. `message` names the offending field.

        Not retryable without changing the request.

        '
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            invalidField:
              value:
                error:
                  code: INVALID_REQUEST
                  message: lineItems[0].quantity must be at least 1
                  requestId: request_sandbox_123
                  retryable: false
            unknownField:
              value:
                error:
                  code: INVALID_REQUEST
                  message: Unrecognized field "paymentMethodId"
                  requestId: request_sandbox_124
                  retryable: false
            mixedCurrency:
              value:
                error:
                  code: INVALID_REQUEST
                  message: All lineItems must use the same currency; only USD is supported
                  requestId: request_sandbox_125
                  retryable: false
    RateLimited:
      description: 'Too many requests. Gateway-enforced; retry with backoff, honouring

        `Retry-After` when present. The sync endpoint''s limit is lower than

        the async endpoint''s. Per-integrator quotas are agreed during

        onboarding when your volume warrants one.

        '
      headers:
        Retry-After:
          description: Number of seconds to wait before retrying.
          schema:
            type: integer
            minimum: 1
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: RATE_LIMIT_EXCEEDED
              message: Too many requests
              requestId: request_sandbox_132
              retryable: true
    InternalError:
      description: 'Unexpected Bilt error. For headless payments, do not retry blindly:

        the charge may have been accepted — check for a `payment.*` webhook

        for the same `orderId` first, and retry with the **same**

        `Idempotency-Key`.

        '
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: INTERNAL_ERROR
              message: Unexpected server error
              requestId: request_sandbox_133
              retryable: false
    Conflict:
      description: Idempotency conflict, or the session is already terminal.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            idempotencyConflict:
              value:
                error:
                  code: IDEMPOTENCY_CONFLICT
                  message: Idempotency-Key was already used with a different request body
                  requestId: request_sandbox_130
                  retryable: false
            sessionAlreadyCompleted:
              value:
                error:
                  code: SESSION_ALREADY_COMPLETED
                  message: The checkout session is already in a terminal state
                  requestId: request_sandbox_131
                  retryable: false
    CustomerNotFound:
      description: '`integratorCustomerId` is not linked to a Bilt member. Send the

        customer through account linking, then retry.

        '
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: CUSTOMER_NOT_FOUND
              message: No linked Bilt member for integratorCustomerId
              requestId: request_sandbox_127
              retryable: false
    ServiceUnavailable:
      description: 'Bilt could not reach the customer''s wallet or another required

        dependency. Nothing was charged. Retry with backoff.

        '
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: PAYMENT_UNAVAILABLE
              message: Payment could not be attempted; try again shortly
              requestId: request_sandbox_134
              retryable: true
    Unauthenticated:
      description: Missing, expired, or wrong-audience access token.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: UNAUTHENTICATED
              message: Missing or invalid access token
              requestId: request_sandbox_126
              retryable: false
  securitySchemes:
    checkoutPartnerOAuth:
      type: oauth2
      description: 'OAuth 2.0 client credentials against the `enterprise-partner`

        Keycloak realm. Bilt issues your client id and client secret during

        onboarding; tokens carry an audience Bilt assigns to your client at

        onboarding, and Bilt

        identifies your integration from the token''s `azp` claim. You do not

        request the audience or any scope yourself: Bilt assigns the audience

        to your client at onboarding, and no scopes are required — a plain

        client-credentials grant with your client id and secret is enough. The

        values you need from Bilt are the token endpoint for the environment,

        your client id, and your client secret. Send the result as

        `Authorization: Bearer <access_token>`. The token URL below is

        **staging** — production is

        `https://www.bilt.com/realms/enterprise-partner/protocol/openid-connect/token`.

        Keep the client secret server-side only.

        '
      flows:
        clientCredentials:
          tokenUrl: https://staging.biltrewards.com/realms/enterprise-partner/protocol/openid-connect/token
          scopes: {}
x-tagGroups:
- name: Checkout SDK
  tags:
  - Integration models
  - Gateway mode
  - Choosing an acquirer
  - One-time payments
  - Headless payments
  - Default payment method
  - Payment webhooks