Method Financial Simulate Payments API

openapi: 3.2.0
info:
  title: Method Simulate Payments API
  version: '2026-03-30'
  license:
    name: Proprietary
    url: https://methodfi.com
  description: "The Method API enables you to retrieve financial data, create payments, and manage\nentities and accounts programmatically. This specification covers the public API\nsurface for version `2026-03-30`.\n\n## Authentication\n\nMost API requests require a Bearer token in the `Authorization` header.\nUse your secret key (`sk_...`) for server-side requests and public key (`pk_...`)\nfor client-side Element requests. Public Message-Level Encryption key discovery\nendpoints are documented separately and do not require authentication.\n\n## Versioning\n\nThe API version is selected via the `Method-Version` header. This spec targets\nversion `2026-03-30`. The SDK sets this header automatically.\n\n## Response Envelope\n\nMost JSON responses are wrapped in a standard envelope:\n\n```json\n{\n  \"success\": true,\n  \"data\": { ... },\n  \"message\": null\n}\n```\n\nThe `/.well-known/jwks.json` endpoint is an exception and returns a bare JWK set.\n\n## Pagination\n\nList endpoints return pagination metadata in response headers:\n`Pagination-Page`, `Pagination-Page-Count`, `Pagination-Page-Limit`,\n`Pagination-Total-Count`, `Pagination-Page-Cursor-Prev`, `Pagination-Page-Cursor-Next`.\n\n## Expandable Fields\n\nCertain resource fields can be expanded from IDs to full objects using the\n`expand` query parameter. Maximum nesting depth is 4 levels.\n"
  contact:
    name: Method Financial
    url: https://methodfi.com
    email: team@methodfi.com
servers:
- url: https://production.methodfi.com
  description: Production
  x-fern-server-name: Production
- url: https://sandbox.methodfi.com
  description: Sandbox
  x-fern-server-name: Sandbox
- url: https://dev.methodfi.com
  description: Development
  x-fern-server-name: Development
security:
- SecretKey: []
tags:
- name: Simulate Payments
  description: Sandbox payment simulation
paths:
  /simulate/payments/{paymentId}:
    post:
      operationId: simulateUpdatePaymentStatus
      summary: Simulate a payment status update
      description: 'Updates the status of a payment in the sandbox environment.

        Use this to test payment lifecycle and status transition flows during development.


        **Development only** - This endpoint is only available in the sandbox environment.

        '
      tags:
      - Simulate Payments
      security:
      - SecretKey: []
      parameters:
      - $ref: '#/components/parameters/method_version'
      - name: paymentId
        in: path
        required: true
        description: Unique identifier for the payment.
        schema:
          type: string
          pattern: ^pmt_\w+$
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - status
              properties:
                status:
                  type: string
                  description: The status to transition the payment to.
                error_code:
                  type: string
                  description: Error code for the simulated failure. Required when status is reversal_required, reversal_processing, or failed.
      responses:
        '200':
          description: The payment with updated status.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PaymentResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalError'
  /simulate/payments/payment_instruments/{pmt_inst_id}:
    post:
      operationId: simulatePostPaymentViaPaymentInstrument
      summary: Simulate a payment via payment instrument
      description: 'Simulates posting a payment through a payment instrument in the sandbox environment.

        Use this to test payment instrument flows during development.


        **Development only** - This endpoint is only available in the sandbox environment.

        This endpoint is available starting with API version `2026-03-30`.

        '
      tags:
      - Simulate Payments
      security:
      - SecretKey: []
      parameters:
      - $ref: '#/components/parameters/method_version'
      - name: pmt_inst_id
        in: path
        required: true
        description: Unique identifier for the payment instrument.
        schema:
          type: string
          pattern: ^pmt_inst_\w+$
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - amount
              properties:
                amount:
                  type: integer
                  description: Payment amount in cents.
                  minimum: 1
      responses:
        '200':
          description: The simulated payment result.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PaymentResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalError'
components:
  schemas:
    Merchant:
      type: object
      required:
      - id
      - parent_name
      - name
      - logo
      - type
      - provider_ids
      - is_temp
      - account_number_formats
      properties:
        id:
          type: string
          description: Unique identifier for the merchant.
          example: mch_aTJMbnCjw34yQ
        parent_name:
          type: string
          description: Name of the parent merchant group.
          example: Chase
        name:
          type: string
          description: Display name of the merchant.
          example: Chase - Credit Cards
        logo:
          type: string
          description: URL of the merchant logo.
          example: https://static.methodfi.com/logos/chase.png
        type:
          $ref: '#/components/schemas/MerchantType'
          description: Type of accounts supported by this merchant.
        provider_ids:
          $ref: '#/components/schemas/MerchantProviderIds'
        is_temp:
          type: boolean
          description: Whether this is a temporary merchant entry.
        account_number_formats:
          type: array
          items:
            type: string
          description: Accepted account number formats.
    AccountExpandableAttribute:
      title: AccountExpandableAttribute
      description: 'The latest attribute ID. This field is expandable. When expanded, returns the full AccountAttribute object.

        '
      oneOf:
      - type: string
        pattern: ^acc_attr_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountAttribute'
    Account:
      type: object
      description: 'An Account represents a financial account (ACH, liability, clearing, or debit card) associated with an Entity. The `type` field indicates which nested details object (`ach`, `liability`, `clearing`, or `debit_card`) is populated. `type` is null for accounts that are disabled before a type was determined.

        '
      required:
      - id
      - holder_id
      - type
      - status
      - consent_status
      - products
      - restricted_products
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the account.
          pattern: ^acc_\w+$
          example: acc_b9q2XVAnNFbp3
        holder_id:
          type: string
          description: The entity ID that owns this account.
          pattern: ^ent_\w+$
          example: ent_au22b1fbFJbp8
        type:
          type:
          - string
          - 'null'
          description: The type of account. Null for accounts that are disabled before a type was determined.
          enum:
          - ach
          - liability
          - clearing
          - debit_card
          - null
        status:
          type: string
          description: Current status of the account.
          enum:
          - active
          - disabled
          - processing
          - pending_exchange
          - closed
        consent_status:
          type: string
          description: Current consent status for data access on this account.
          enum:
          - pending
          - withdrawn
          - approved
        ach:
          $ref: '#/components/schemas/AccountACH'
        liability:
          $ref: '#/components/schemas/AccountLiability'
        clearing:
          $ref: '#/components/schemas/AccountClearing'
        debit_card:
          $ref: '#/components/schemas/AccountDebitCard'
        error:
          $ref: '#/components/schemas/AccountResourceError'
        metadata:
          $ref: '#/components/schemas/Metadata'
        products:
          type: array
          description: Products currently active for this account.
          items:
            type: string
        restricted_products:
          type: array
          description: Products restricted from this account.
          items:
            type: string
        subscriptions:
          type: array
          description: Subscriptions currently active for this account. Only present for liability accounts.
          items:
            type: string
        available_subscriptions:
          type: array
          description: Subscriptions available to be enrolled for this account. Only present for liability accounts.
          items:
            type: string
        restricted_subscriptions:
          type: array
          description: Subscriptions restricted from this account. Only present for liability accounts.
          items:
            type: string
        latest_verification_session:
          title: AccountExpandableLatestVerificationSession
          description: 'The latest verification session ID. This field is expandable. When expanded, returns the full AccountVerificationSession object.

            '
          oneOf:
          - type: string
            pattern: ^avf_\w+$
          - type: 'null'
          - $ref: '#/components/schemas/AccountVerificationSession'
        balance:
          $ref: '#/components/schemas/AccountExpandableBalance'
        payoff:
          $ref: '#/components/schemas/AccountExpandablePayoff'
        payment_instrument:
          $ref: '#/components/schemas/AccountExpandablePaymentInstrument'
        card_brand:
          $ref: '#/components/schemas/AccountExpandableCardBrand'
        update:
          $ref: '#/components/schemas/AccountExpandableUpdate'
        attribute:
          $ref: '#/components/schemas/AccountExpandableAttribute'
        sensitive:
          $ref: '#/components/schemas/AccountExpandableSensitive'
        created_at:
          type: string
          format: date-time
          description: Timestamp when the account was created.
        updated_at:
          type: string
          format: date-time
          description: Timestamp when the account was last updated.
    AccountDebitCard:
      type:
      - object
      - 'null'
      description: Debit card account details. Present when `type` is `debit_card`.
      properties:
        network:
          type: string
          description: The card network.
        mask:
          type: string
          description: Last 4 digits of the card number.
        issuer:
          type: string
          description: The card issuer.
    AccountSensitiveResourceError:
      type:
      - object
      - 'null'
      description: Error details when retrieving account sensitive data fails.
      required:
      - type
      - code
      - sub_type
      - message
      properties:
        type:
          type: string
          description: The category of sensitive data error.
          enum:
          - ACCOUNT_SENSITIVE_FAILED
        code:
          type: integer
          description: Numeric error code (17XXX range).
          enum:
          - 17001
        sub_type:
          type: string
          description: Specific sensitive data error classification.
          enum:
          - ACCOUNT_SENSITIVE_FAILED_VERIFICATION_REQUIRED
        message:
          type: string
          description: Human-readable error description.
      example:
        type: ACCOUNT_SENSITIVE_FAILED
        code: 17001
        sub_type: ACCOUNT_SENSITIVE_FAILED_VERIFICATION_REQUIRED
        message: Account sensitive failed due to missing required verification.
    AccountExpandablePaymentInstrument:
      title: AccountExpandablePaymentInstrument
      description: 'The latest payment instrument ID. This field is expandable. When expanded, returns the full AccountPaymentInstrument object.

        '
      oneOf:
      - type: string
        pattern: ^pmt_inst_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountPaymentInstrument'
    ErrorEnvelope:
      type: object
      required:
      - success
      - data
      - message
      properties:
        success:
          type: boolean
          description: Always `false` for error responses.
        data:
          type: object
          required:
          - error
          properties:
            error:
              $ref: '#/components/schemas/ErrorObject'
        message:
          type: string
    ResourceError:
      type:
      - object
      - 'null'
      required:
      - type
      - code
      - message
      properties:
        type:
          type: string
        code:
          type: integer
        sub_type:
          type:
          - string
          - 'null'
        message:
          type: string
    BalanceResourceError:
      type:
      - object
      - 'null'
      description: Error details when a balance sync fails.
      required:
      - type
      - code
      - sub_type
      - message
      properties:
        type:
          type: string
          description: The category of balance error.
          enum:
          - BALANCE_FAILED
        code:
          type: integer
          description: Numeric error code (20XXX range).
          enum:
          - 20001
        sub_type:
          type: string
          description: Specific balance error classification.
          enum:
          - BALANCE_TEMPORARILY_UNAVAILABLE
        message:
          type: string
          description: Human-readable error description.
      example:
        type: BALANCE_FAILED
        code: 20001
        sub_type: BALANCE_TEMPORARILY_UNAVAILABLE
        message: Balance is temporarily unavailable for this account.
    AccountExpandableSensitive:
      title: AccountExpandableSensitive
      description: 'The latest sensitive ID. This field is expandable. When expanded, returns the full AccountSensitive object.

        '
      oneOf:
      - type: string
        pattern: ^astv_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountSensitive'
    Payment:
      type: object
      description: A Payment represents a transfer of funds between two accounts.
      required:
      - id
      - source
      - destination
      - amount
      - status
      - type
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the payment.
          pattern: ^pmt_\w+$
          example: pmt_rPrDPEwyCVUcm
        reversal_id:
          type:
          - string
          - 'null'
          description: Identifier of the associated reversal, if any.
          pattern: ^rvs_\w+$
        reversal_account:
          type:
          - string
          - 'null'
          description: Account ID used for the reversal leg of the payment.
          pattern: ^acc_\w+$
        payment_instrument:
          type:
          - string
          - 'null'
          description: Identifier of the payment instrument used to create this payment, if any.
          pattern: ^pmt_inst_\w+$
          example: pmt_inst_aTJMbnCjw34yQ
        source_trace_id:
          type:
          - string
          - 'null'
          description: Trace identifier for the source side of the payment.
        destination_trace_id:
          type:
          - string
          - 'null'
          description: Trace identifier for the destination side of the payment.
        source:
          title: PaymentExpandableSource
          description: 'The source account ID. This field is expandable. When expanded, returns the full Account object.

            '
          anyOf:
          - type: string
            pattern: ^acc_\w+$
          - type: 'null'
          - $ref: '#/components/schemas/Account'
        destination:
          title: PaymentExpandableDestination
          description: 'The destination account ID. This field is expandable. When expanded, returns the full Account object.

            '
          anyOf:
          - type: string
            pattern: ^acc_\w+$
          - type: 'null'
          - $ref: '#/components/schemas/Account'
        amount:
          type: integer
          description: Payment amount in cents.
          minimum: 0
          example: 5000
        description:
          type:
          - string
          - 'null'
          description: Human-readable description for the payment.
        status:
          type: string
          description: Current status of the payment.
          enum:
          - pending
          - processing
          - sent
          - posted
          - settled
          - failed
          - reversed
          - canceled
          - cashed
        fund_status:
          type:
          - string
          - 'null'
          description: The current status of the payment funds.
          enum:
          - transmitting
          - transmitted
          - requested
          - clearing
          - pending
          - hold
          - sent
          - posted
          - cashed
          - unknown
          - pending_consolidation
          - pending_clearing
          - failed
          - null
        estimated_completion_date:
          type:
          - string
          - 'null'
          format: date
          description: Estimated date when the payment will be completed (YYYY-MM-DD).
        source_settlement_date:
          type:
          - string
          - 'null'
          format: date
          description: The expected or actual settlement date for the source side of the payment.
        destination_settlement_date:
          type:
          - string
          - 'null'
          format: date
          description: The expected or actual settlement date for the destination side of the payment.
        destination_posted_date:
          type:
          - string
          - 'null'
          format: date
          description: The date the destination side of the payment was posted.
        source_status:
          type:
          - string
          - 'null'
          description: The status of the source side of the payment.
        destination_status:
          type:
          - string
          - 'null'
          description: The status of the destination side of the payment.
        destination_payment_method:
          type:
          - string
          - 'null'
          description: The payment method used for the destination.
        fee:
          type:
          - object
          - 'null'
          description: Fee associated with the payment.
          required:
          - type
          - amount
          properties:
            type:
              type: string
              description: The fee type.
              enum:
              - total
            amount:
              type: integer
              description: Fee amount in cents.
              minimum: 0
        type:
          type: string
          description: The type of payment.
          enum:
          - standard
          - clearing
        error:
          $ref: '#/components/schemas/PaymentResourceError'
        idempotency_key:
          type:
          - string
          - 'null'
          description: The idempotency key provided when the payment was created, if any.
        metadata:
          $ref: '#/components/schemas/Metadata'
        created_at:
          type: string
          format: date-time
          description: Timestamp when the payment was created.
        updated_at:
          type: string
          format: date-time
          description: Timestamp when the payment was last updated.
    AccountBalance:
      type: object
      description: A balance record for an account.
      required:
      - id
      - account_id
      - status
      - amount
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the balance.
          pattern: ^bal_\w+$
          example: bal_dKe9ehC3hEBYy
        account_id:
          type: string
          description: The account this balance belongs to.
          pattern: ^acc_\w+$
        status:
          type: string
          description: Current status of the balance request.
          enum:
          - completed
          - pending
          - failed
        amount:
          type:
          - number
          - 'null'
          description: The balance amount in cents.
        error:
          $ref: '#/components/schemas/BalanceResourceError'
        created_at:
          type: string
          format: date-time
          description: Timestamp when the balance was created.
        updated_at:
          type: string
          format: date-time
          description: Timestamp when the balance was last updated.
    AccountExpandablePayoff:
      title: AccountExpandablePayoff
      description: 'The latest payoff ID. This field is expandable. When expanded, returns the full AccountPayoff object.

        '
      oneOf:
      - type: string
        pattern: ^pyf_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountPayoff'
    SuccessEnvelope:
      type: object
      description: Standard envelope for successful responses that return a single payload.
      required:
      - success
      - data
      - message
      properties:
        success:
          type: boolean
          description: Always `true` for successful responses.
        data:
          description: Operation-specific response payload.
        message:
          type:
          - string
          - 'null'
      example:
        success: true
        data: {}
        message: null
    AccountExpandableUpdate:
      title: AccountExpandableUpdate
      description: 'The latest update ID. This field is expandable. When expanded, returns the full AccountUpdate object.

        '
      oneOf:
      - type: string
        pattern: ^upd_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountUpdate'
    AccountExpandableBalance:
      title: AccountExpandableBalance
      description: 'The latest balance ID. This field is expandable. When expanded, returns the full AccountBalance object.

        '
      oneOf:
      - type: string
        pattern: ^bal_\w+$
      - type: 'null'
      - $ref: '#/components/schemas/AccountBalance'
    AccountAttribute:
      type: object
      description: An attribute record for an account containing financial data attributes.
      required:
      - id
      - account_id
      - status
      - attributes
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the account attribute.
          pattern: ^acc_attr_\w+$
          example: acc_attr_eTJMbnCjw34yQ
        account_id:
          type: string
          description: The account this attribute belongs to.
          pattern: ^acc_\w+$
        status:
          type: string
          description: Current status of the attribute request.
          enum:
          - completed
          - pending
          - failed
        attributes:
          type: object
          description: Financial data attributes for the account.
          additionalProperties: true
        error:
          $ref: '#/components/schemas/ResourceError'
        created_at:
          type: string
          format: date-time
          description: Timestamp when the attribute was created.
        updated_at:
          type: string
          format: date-time
          description: Timestamp when the attribute was last updated.
    AccountCardBrand:
      type: object
      description: Card brand information for an account.
      required:
      - id
      - account_id
      - status
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the card brand.
          pattern: ^cbrd_\w+$
          example: cbrd_aTJMbnCjw34yQ
        account_id:
          type: string
          description: The account this card brand belongs to.
          pattern: ^acc_\w+$
        brands:
          type:
          - array
          - 'null'
          description: Array of card brand entries for this account.
          items:
            type: object
            properties:
              id:
                type: string
                description: Unique identifier for the brand entry.
              card_product_id:
                type:
                - string
                - 'null'
                description: Associated card product ID.
              description:
                type: string
                description: Description of the brand.
              name:
                type: string
                description: Name of the brand.
              issuer:
                type: string
                description: The card issuer.
              network:
                type: string
                description: The card network.
              network_tier:
                type: string
                description: The tier of the card network.
              type:
                type:
                - string
                - 'null'
                description: The brand type.
              url:
                type: string
                description: URL for the brand image.
        source:
          type:
          - string
          - 'null'
          description: Source of the card brand data.
          enum:
          - network
          - method
          - null
        shared:
          type: boolean
          description: Whether this card brand record is shared.
        network:
          type:
          - string
          - 'null'
          description: The card network. Deprecated in favor of brands[].network.
          enum:
          - visa
          - mastercard
          - amex
          - discover
          - null
        issuer:
          type:
          - string
          - 'null'
          description: The card issuer. Deprecated in favor of brands[].issuer.
        last4:
          type:
          - string
          - 'null'
          description: Last 4 digits of the card number. Deprecated in favor of brands[].
        status:
          type: string
          description: Current status of the card brand request.
          enum:
          - completed
          - pending
          - failed
        error:
          $ref: '#/components/schemas/ResourceError'
        created_at:
          type: string
          format: date-time
          description: Timestamp when the card brand was created.
        updated_at:
          type: string
          format: date-time
          description: Timestamp when the card brand was last updated.
    AccountACH:
      type:
      - object
      - 'null'
      description: ACH account details. Present when `type` is `ach`.
      properties:
        routing:
          type: string
          description: The ACH routing number.
        number:
          type: string
          description: The ACH account number.
        type:
          type: string
          description: The type of ACH account.
          enum:
          - checking
          - savings
    PaymentResponse:
      allOf:
      - $ref: '#/components/schemas/SuccessEnvelope'
      - type: object
        properties:
          data:
            $ref: '#/components/schemas/Payment'
    AccountUpdate:
      type: object
      description: An update record for an account.
      required:
      - id
      - account_id
      - status
      - type
      - created_at
      - updated_at
      properties:
        id:
          type: string
          description: Unique identifier for the update.
          pattern: ^upd_\w+$
          example: upd_aTJMbnCjw34yQ
        account_id:
          type: string
          description: The account this update belongs to.
          pattern: ^acc_\w+$
        status:
          type: string
          description: Current status of the update.
          enum:
          - completed
          - pending
          - failed
        type:
          type: string
          description: The liability type of the account being updated.
          enum:
          - credit_card
          - auto_loan
          - mortgage
          - personal_loan
          - student_loan
          - student_loans
          - collection
          - credit_builder
          - insurance
          - loan
          - medical
          - utility
          - bnpl
          - fintech
        source:
          type: string
          description: The data source used for this update.
          enum:
          - direct
          - snapshot
        data_as_of:
          type:
          - string
          - 'null'
          format: date-time
          description: The timestamp of the data used to complete this update.
        credit_card:
          type:
          - object
          - 'null'
          description: Credit card update data. Present when `type` is `credit_card`.
          properties:
            sub_type:
              type:
              - string
              - 'null'
            opened_at:
              type:
              - string
              - 'null'
              format: date
            closed_at:
              type:
              - string
              - 'null'
              format: date
            balance:
              type:
              - integer
              - 'null'
              description: Current balance in cents.
            last_payment_amount:
              type:
              - integer
              - 'null'
              description: Last payment amount in cents.
            last_payment_date:
              type:
              - string
              - 'null'
              format: date
            next_payment_due_date:
              type:
              - string
              - 'null'
              format: date
            next_payment_minimum_amount:
              type:
              - integer
              - 'null'
              description: Minimum payment due in cents.
            interest_rate_type:
              type:
              - string
              - 'null'
            interest_rate_percentage_max:
              type:
              - number
              - 'null'
            interest_rate_percentage_min:
              type:
              - number
              - 'null'
            available_credit:
              type:
              - integer
              - 'null'
              description: Available credit in cents.
            credit_limit:
              type:
              - integer
              - 'null'
              description: Credit limit in cents.
            usage_pattern:
              type:
              - string
              - 'null'
        auto_loan:
          type:
          - object
          - 'null'
          description: Auto loan update data. Present when `type` is `auto_loan`.
          properties:
            sub_type:
              type:
              - string
              - 'null'
            opened_at:
              type:
              - string
              - 'null'
              format: date
            closed_at:
              type:
              - string
              - 'null'
              format: date
            balance:
              type:
              - integer
              - 'null'
              description: Current balance in cents.
            last_payment_amount:
              type:
              - integer
              - 'null'
              description: Last payment amount in cents.
            last_payment_date:
              type:
              - strin

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# Full source: https://raw.githubusercontent.com/api-evangelist/method-financial/refs/heads/main/openapi/method-financial-simulate-payments-api-openapi.yml