> ## Documentation Index
> Fetch the complete documentation index at: https://docs.natural.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> When building application code, use `@naturalpay/sdk` for TypeScript or `naturalpay` for Python.
> When searching Natural documentation, use the docs MCP at `https://docs.natural.com/mcp`.
> Use the Natural CLI for terminal and CI automation.
> Start integration development and testing in the sandbox. Do not use production unless the user explicitly requests it.
> For sandbox requests that require `customerPartyId`, list customers first. Reuse only the intended fixture; otherwise create a customer.
> REST and SDK amounts use integer minor units. Payments MCP amounts use decimal strings with a required currency code.

# Sandbox: simulate a voice call

> Drive a Sandbox voice session to a call outcome without placing a phone call



## OpenAPI

````yaml /api-reference/openapi-early-access.json post /simulations/voice-sessions/{voiceSessionId}
openapi: 3.1.1
info:
  title: Natural API (early access)
  version: 0.2.0
  description: |-
    Early-access endpoints of Natural's payments API.

    **Base URL:** `https://api.natural.com`

    For access: hi@natural.com
servers:
  - url: https://api.natural.com
    description: Production
security: []
tags:
  - name: Payment attachments
    description: Private supporting documents for payments
  - name: Subscriptions
    description: Subscriptions and installments paid by card
  - name: Agent Cards
    description: Cards an agent requests for one purchase at one merchant
  - name: Card Transactions
    description: Purchases and refunds on Natural-issued cards
  - name: Simulations
    description: Sandbox-only simulation controls
paths:
  /simulations/voice-sessions/{voiceSessionId}:
    post:
      tags:
        - Simulations
      summary: 'Sandbox: simulate a voice call'
      description: >-
        Drive a Sandbox voice session to a call outcome without placing a phone
        call
      operationId: simulations.simulateVoiceSession
      parameters:
        - name: voiceSessionId
          in: path
          required: true
          schema:
            type: string
            pattern: ^vos_[0-9a-f]{32}$
            description: Voice session ID (vos_*).
        - name: Idempotency-Key
          in: header
          required: true
          schema:
            type: string
            maxLength: 255
          description: >-
            Unique key for safely retrying a request without creating
            duplicates.
        - name: X-Instance-ID
          in: header
          required: false
          schema:
            anyOf:
              - type: string
                maxLength: 1024
              - type: 'null'
          description: >-
            Caller-chosen identifier for the agent run, session, or
            conversation, required when an agent moves money.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                data:
                  type: object
                  properties:
                    attributes:
                      type: object
                      properties:
                        action:
                          enum:
                            - pay
                            - decline
                            - sendLink
                            - hangUp
                            - expire
                          type: string
                          description: >-
                            `pay` and `decline` place a call that charges a
                            success or decline test card. `sendLink` places a
                            call that records the payment link as sent and texts
                            nobody. `hangUp` places a call that ends unpaid.
                            Each of these ends its call. `expire` closes a
                            session nobody dialed.
                        customerPartyId:
                          type: string
                          pattern: ^pty_[0-9a-f]{32}$
                          description: >-
                            Customer the session belongs to. Omit to act for
                            your own party.
                      required:
                        - action
                      additionalProperties: false
                  required:
                    - attributes
                  additionalProperties: false
              required:
                - data
              additionalProperties: false
            examples:
              default:
                summary: Default
                value:
                  data:
                    attributes:
                      action: pay
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    $ref: '#/components/schemas/VoiceSession'
                required:
                  - data
                additionalProperties: false
                title: VoiceSessionResponse
              examples:
                default:
                  summary: Default
                  value:
                    data:
                      id: vos_019d0a1b2c3d4e5f60718293a4b5c6f0
                      type: voiceSession
                      attributes:
                        kind: payment
                        status: ended
                        referenceId: call_8842
                        callerPhone: '+14155550123'
                        dialUri: null
                        dialExpiresAt: '2026-09-09T18:15:00.000Z'
                        returnTarget: sip:agent-9920@sip.partner.example.com
                        call:
                          startedAt: '2026-09-09T18:01:05.000Z'
                          endedAt: '2026-09-09T18:02:50.000Z'
                          durationSeconds: 105
                          endedBy: assistant
                          summary: >-
                            The caller confirmed the order and paid. A return
                            transfer was requested.
                          returnRequestedAt: '2026-09-09T18:02:50.000Z'
                        completedAt: '2026-09-09T18:02:31.000Z'
                        payment:
                          outcome: paid
                          linkSentAt: null
                          failedAttempts: 0
                          failure: null
                        createdAt: '2026-09-09T18:00:00.000Z'
                        updatedAt: '2026-09-09T18:02:50.000Z'
                      relationships:
                        paymentIntent:
                          data:
                            type: paymentIntent
                            id: pmi_019d0a1b2c3d4e5f60718293a4b5c6d7
                        customerParty:
                          data:
                            type: party
                            id: pty_019cd1798d627ad9bc302511c4f2c115
          headers:
            X-RateLimit-Limit:
              description: Maximum requests allowed per window.
              schema:
                type: integer
            X-RateLimit-Remaining:
              description: Requests remaining in current window.
              schema:
                type: integer
            X-RateLimit-Reset:
              description: Unix timestamp when rate limit resets.
              schema:
                type: integer
        '400':
          description: Validation Error
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: invalid_value
                        detail: >-
                          The information you entered isn't valid. Please check
                          it and try again.
                        status: '400'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: unauthenticated
                        detail: Authentication is required.
                        status: '401'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '403':
          description: Forbidden
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: forbidden
                        detail: You do not have permission to perform this action.
                        status: '403'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '404':
          description: >-
            Not Found. Returned when the resource does not exist, or when it
            exists but is not accessible to your account. The two cases are
            intentionally indistinguishable, so that resource IDs cannot be
            enumerated by probing.
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: not_found
                        detail: The requested resource was not found.
                        status: '404'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '409':
          description: Conflict
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: conflict
                        detail: The request conflicts with the current resource state.
                        status: '409'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '422':
          description: >-
            Validation Error. The response contains one error object for each
            invalid request value.
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: invalid_value
                        detail: 'Too big: expected string to have <=80 characters'
                        status: '422'
                        source:
                          pointer: /data/attributes/description
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '428':
          description: Precondition Required
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: mfa_required
                        detail: MFA verification required.
                        status: '428'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '429':
          description: Too Many Requests
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: rate_limited
                        detail: Too many requests. Please try again later.
                        status: '429'
                        meta:
                          supportId: req_a1b2c3d4e5f6
          headers:
            Retry-After:
              description: Seconds to wait before retrying.
              schema:
                type: integer
            X-RateLimit-Limit:
              description: Maximum requests allowed per window.
              schema:
                type: integer
            X-RateLimit-Remaining:
              description: Requests remaining in current window.
              schema:
                type: integer
            X-RateLimit-Reset:
              description: Unix timestamp when rate limit resets.
              schema:
                type: integer
        '500':
          description: Internal Server Error
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: server_error
                        detail: Something went wrong.
                        status: '500'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '501':
          description: Not Implemented
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: not_implemented
                        detail: This operation is not available.
                        status: '501'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '502':
          description: Bad Gateway
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: bad_gateway
                        detail: >-
                          We couldn't complete that request because one of
                          Natural's services returned an unexpected response.
                          Please try again.
                        status: '502'
                        meta:
                          supportId: req_a1b2c3d4e5f6
        '503':
          description: Service Unavailable
          content:
            application/json:
              schema:
                type: object
                properties:
                  errors:
                    type: array
                    minItems: 1
                    items:
                      type: object
                      properties:
                        code:
                          type: string
                          description: Stable lower-snake-case public error code.
                        detail:
                          type: string
                          description: Safe user-facing error detail.
                        status:
                          type: string
                          description: HTTP status code as a string.
                        source:
                          type: object
                          description: Location of the invalid request value.
                          properties:
                            pointer:
                              type: string
                              description: JSON Pointer to the invalid request value.
                            parameter:
                              type: string
                              description: Name of the invalid query parameter.
                            header:
                              type: string
                              description: Name of the invalid request header.
                          additionalProperties: false
                        meta:
                          type: object
                          description: >-
                            Additional error context, including support and
                            provider details when available.
                          properties:
                            supportId:
                              type: string
                              description: Request/support ID for troubleshooting.
                            limitScope:
                              type: string
                              enum:
                                - merchant
                                - program
                              description: >-
                                Which family of acquiring limit refused the
                                payment. Thresholds and usage are never
                                disclosed.
                            connectionStatus:
                              type: string
                              enum:
                                - login_required
                                - disconnected
                              description: >-
                                External account connection state when the error
                                is repairable by relinking.
                            provider:
                              type: object
                              description: Provider error details, when available.
                              properties:
                                name:
                                  type: string
                                  enum:
                                    - plaid
                                  description: Provider that returned the underlying error.
                                errorCode:
                                  type: string
                                  description: Provider error code, when available.
                                errorType:
                                  type: string
                                  description: Provider error type, when available.
                                requestId:
                                  type: string
                                  description: Provider request ID for troubleshooting.
                              required:
                                - name
                              additionalProperties: false
                          required:
                            - supportId
                          additionalProperties: false
                      required:
                        - code
                        - detail
                        - status
                        - meta
                      additionalProperties: false
                required:
                  - errors
                additionalProperties: false
              examples:
                default:
                  summary: Default
                  value:
                    errors:
                      - code: service_unavailable
                        detail: The service is temporarily unavailable.
                        status: '503'
                        meta:
                          supportId: req_a1b2c3d4e5f6
      security:
        - HTTPBearer: []
components:
  schemas:
    VoiceSession:
      type: object
      properties:
        id:
          type: string
          pattern: ^vos_[0-9a-f]{32}$
          description: Voice session ID (vos_*).
        type:
          description: Resource type. Always `voiceSession`.
          type: string
          enum:
            - voiceSession
        attributes:
          anyOf:
            - type: object
              properties:
                kind:
                  description: Collects payment for a payment intent.
                  type: string
                  enum:
                    - payment
                status:
                  enum:
                    - awaitingCall
                    - inProgress
                    - ended
                    - canceled
                    - expired
                  type: string
                  description: >-
                    Call lifecycle, independent of payment outcome. `ended`
                    requires a recorded call end. `expired` means the dial
                    window or call time limit passed without a recorded end.
                referenceId:
                  anyOf:
                    - type: string
                    - type: 'null'
                  description: Reference supplied when the session was created, or null.
                callerPhone:
                  anyOf:
                    - type: string
                    - type: 'null'
                  description: >-
                    Supplied caller phone number, or null for a session without
                    one.
                dialUri:
                  anyOf:
                    - type: string
                    - type: 'null'
                  description: >-
                    Dial destination while the session accepts a call and you
                    have permission to create payment voice sessions. Otherwise
                    null. Treat it as opaque: store it from the create response
                    and never build it from the session ID.
                dialExpiresAt:
                  type: string
                  description: >-
                    RFC 3339 deadline for starting the session's one permitted
                    call.
                returnTarget:
                  anyOf:
                    - type: string
                    - type: 'null'
                  description: >-
                    Requested return destination, or null. This does not confirm
                    the destination answered.
                call:
                  type: object
                  properties:
                    startedAt:
                      anyOf:
                        - type: string
                        - type: 'null'
                      description: >-
                        Reported call start time in RFC 3339, or null when
                        unavailable.
                    endedAt:
                      anyOf:
                        - type: string
                        - type: 'null'
                      description: >-
                        Time the call was recorded as ended in RFC 3339, or
                        null.
                    durationSeconds:
                      anyOf:
                        - type: integer
                          minimum: 0
                        - type: 'null'
                      description: Reported call duration in seconds, or null.
                    endedBy:
                      anyOf:
                        - enum:
                            - caller
                            - assistant
                            - unknown
                          type: string
                        - type: 'null'
                      description: >-
                        Reported party ending the call. Null before an end is
                        recorded.
                    summary:
                      anyOf:
                        - type: string
                        - type: 'null'
                      description: Redacted call summary, or null.
                    returnRequestedAt:
                      anyOf:
                        - type: string
                        - type: 'null'
                      description: >-
                        Time a return transfer was requested in RFC 3339, or
                        null. This does not confirm the return leg connected.
                  required:
                    - startedAt
                    - endedAt
                    - durationSeconds
                    - endedBy
                    - summary
                    - returnRequestedAt
                  additionalProperties: false
                  title: VoiceSessionCall
                completedAt:
                  anyOf:
                    - type: string
                    - type: 'null'
                  description: >-
                    RFC 3339 time the session closed, or null. Set once the call
                    has ended and its result is known, or the session expired or
                    was canceled. `voiceSession.completed` fires once then.
                createdAt:
                  type: string
                  description: RFC 3339 time the session was created.
                updatedAt:
                  type: string
                  description: RFC 3339 time the stored session last changed.
                payment:
                  type: object
                  properties:
                    outcome:
                      anyOf:
                        - enum:
                            - paid
                            - linkSent
                            - unpaid
                          type: string
                        - type: 'null'
                      description: >-
                        `paid` when the card was charged on the call. `linkSent`
                        when voice payment did not succeed and the caller was
                        texted the payment link. `unpaid` otherwise. Null until
                        the result is known, which can be while the call is
                        still in progress. A later link payment does not change
                        it. New values may be added.
                    linkSentAt:
                      anyOf:
                        - type: string
                        - type: 'null'
                      description: >-
                        RFC 3339 time the payment link was texted to the caller,
                        or null.
                    failedAttempts:
                      type: integer
                      minimum: 0
                      description: Card payments that failed during this session.
                    failure:
                      anyOf:
                        - type: object
                          properties:
                            code:
                              anyOf:
                                - type: string
                                - type: 'null'
                              description: >-
                                Failure code, when known. New codes may be
                                added.
                            reason:
                              anyOf:
                                - type: string
                                - type: 'null'
                              description: Explanation of the failure.
                            advice:
                              anyOf:
                                - enum:
                                    - doNotRetry
                                    - tryAgainLater
                                    - confirmCardData
                                  type: string
                                - type: 'null'
                              description: Recommended payer action, when known.
                          required:
                            - code
                            - reason
                            - advice
                          additionalProperties: false
                        - type: 'null'
                      description: The last failed card payment in this session, or null.
                  required:
                    - outcome
                    - linkSentAt
                    - failedAttempts
                    - failure
                  additionalProperties: false
                  title: VoiceSessionPayment
              required:
                - kind
                - status
                - referenceId
                - callerPhone
                - dialUri
                - dialExpiresAt
                - returnTarget
                - call
                - completedAt
                - createdAt
                - updatedAt
                - payment
              additionalProperties: false
              title: PaymentVoiceSessionAttributes
          title: VoiceSessionAttributes
          description: >-
            `kind` is the session's purpose and names the block that holds its
            result. New kinds may be added; ignore kinds you don't handle.
        relationships:
          type: object
          properties:
            paymentIntent:
              type: object
              properties:
                data:
                  anyOf:
                    - type: object
                      properties:
                        type:
                          description: Resource type. Always `paymentIntent`.
                          type: string
                          enum:
                            - paymentIntent
                        id:
                          type: string
                          pattern: ^pmi_[0-9a-f]{32}$
                      required:
                        - type
                        - id
                      additionalProperties: false
                      title: ResourceIdentifier
                      description: Related resource identifier.
                    - type: 'null'
              required:
                - data
              additionalProperties: false
              title: NullableToOneRelationship
              description: Associated payment intent. Set on `payment` sessions.
            customerParty:
              type: object
              properties:
                data:
                  anyOf:
                    - type: object
                      properties:
                        type:
                          description: Resource type. Always `party`.
                          type: string
                          enum:
                            - party
                        id:
                          type: string
                          pattern: ^pty_[0-9a-f]{32}$
                      required:
                        - type
                        - id
                      additionalProperties: false
                      title: ResourceIdentifier
                      description: Related resource identifier.
                    - type: 'null'
              required:
                - data
              additionalProperties: false
              title: NullableToOneRelationship
              description: Associated Natural customer, or null when none is associated.
          required:
            - paymentIntent
            - customerParty
          additionalProperties: false
          title: VoiceSessionRelationships
      required:
        - id
        - type
        - attributes
        - relationships
      additionalProperties: false
      title: VoiceSessionResource
  securitySchemes:
    HTTPBearer:
      type: http
      scheme: bearer
      description: >-
        Bearer authentication: send your API key, agent key, or OAuth access
        token as `Authorization: Bearer <credential>`.

````

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