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

# List scored customer payment candidates for a bank transaction

> <Note>Required API key scope: `accounting:read`</Note>

Returns a 5-band scored list of `order_payments` candidates that could be
matched to an inbound bank deposit. Only applies to inbound transactions
(`direction='in'` or NULL). Returns `already_matched: true` if the transaction
is already matched.

**Scoring bands:**
- 1.0 -- Exact amount + same calendar day
- 0.9 -- Exact amount + within 2 days
- 0.8 -- Within $0.01 + same day
- 0.7 -- Within $0.05 + within 2 days + customer name in description
- 0.6 -- Within $0.05 fallback (remaining candidates)

**A.2 Multi-invoice payments:** Payments where `order_id IS NULL` but
have one or more rows in `order_payment_applications` are flagged with
`is_multi_application: true` and `application_count`.

**No GL postings occur on match.** GL was posted when the payment receipt
was recorded. This endpoint is read-only scoring only.




## OpenAPI

````yaml /openapi.yaml get /accounting/bank-transactions/{bank_transaction_id}/customer-payment-candidates
openapi: 3.1.0
info:
  title: Arcus ERP Public API
  version: 1.0.0
  description: >
    Arcus ERP public REST API. Designed for external integrations and data
    migration.


    **Authentication.** Bearer token (API key) via the `Authorization` header.

    Format: `Authorization: Bearer ark_live_ent_<code>_<random>` (or
    `ark_test_*` for sandbox).

    API keys are issued per-entity in **Settings > Developers > API Keys**.


    **Entity scoping.** The entity is encoded in the API key prefix; routes are
    flat

    (e.g. `/v1/accounts`, `/v1/orders`, `/v1/products`). A small set of platform
    endpoints

    (migration, reconciliation, events, webhook endpoints, API keys) use the

    `/v1/entities/{entity_id}/...` form -- those are noted in their tags.


    **Key capabilities.**
      - Related-resource hydration via `?expand[]=` (see `x-arcus-expand` on each resource).
      - Cursor-based pagination (`starting_after` / `ending_before` / `limit`).
      - Idempotency via the `Idempotency-Key` header.
      - Webhook events for asynchronous notification.
      - Conditional requests / ETag for cache validation.
servers:
  - url: https://api.arcuserp.com/v1
    description: Arcus ERP API (accepts both live `ark_live_*` and test `ark_test_*` keys)
  - url: https://dev-api.arcuserp.com/v1
    description: >-
      Dev sandbox API (test-only data, accepts `ark_test_*` keys against dev
      RDS)
security: []
paths:
  /accounting/bank-transactions/{bank_transaction_id}/customer-payment-candidates:
    get:
      tags:
        - Accounting
      summary: List scored customer payment candidates for a bank transaction
      description: >
        <Note>Required API key scope: `accounting:read`</Note>


        Returns a 5-band scored list of `order_payments` candidates that could
        be

        matched to an inbound bank deposit. Only applies to inbound transactions

        (`direction='in'` or NULL). Returns `already_matched: true` if the
        transaction

        is already matched.


        **Scoring bands:**

        - 1.0 -- Exact amount + same calendar day

        - 0.9 -- Exact amount + within 2 days

        - 0.8 -- Within $0.01 + same day

        - 0.7 -- Within $0.05 + within 2 days + customer name in description

        - 0.6 -- Within $0.05 fallback (remaining candidates)


        **A.2 Multi-invoice payments:** Payments where `order_id IS NULL` but

        have one or more rows in `order_payment_applications` are flagged with

        `is_multi_application: true` and `application_count`.


        **No GL postings occur on match.** GL was posted when the payment
        receipt

        was recorded. This endpoint is read-only scoring only.
      operationId: listCustomerPaymentCandidatesV1
      parameters:
        - name: bank_transaction_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: UUID of the inbound bank transaction to score candidates for
      responses:
        '200':
          description: Candidate list (may be empty)
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: object
                    properties:
                      bank_transaction:
                        type: object
                        properties:
                          id:
                            type: string
                            format: uuid
                          amount:
                            type: number
                          transaction_date:
                            type: string
                            format: date-time
                          direction:
                            type: string
                            nullable: true
                          description:
                            type: string
                      order_payments:
                        type: array
                        items:
                          type: object
                          properties:
                            id:
                              type: string
                              format: uuid
                            order_id:
                              type: string
                              format: uuid
                              nullable: true
                            amount:
                              type: number
                            posted_at:
                              type: string
                              format: date-time
                              nullable: true
                            payment_method:
                              type: string
                              nullable: true
                            status:
                              type: string
                            check_number:
                              type: string
                              nullable: true
                            external_reference:
                              type: string
                              nullable: true
                            customer_name:
                              type: string
                              nullable: true
                            score:
                              type: number
                            match_reason:
                              type: string
                            days_apart:
                              type: number
                            is_multi_application:
                              type: boolean
                            application_count:
                              type: integer
                            display_label:
                              type: string
                            applications:
                              type: array
                              description: >-
                                Per-invoice breakdown for multi-application
                                payments (B.1)
                              items:
                                type: object
                                properties:
                                  order_id:
                                    type: string
                                    format: uuid
                                  order_number:
                                    type: string
                                    nullable: true
                                  amount_applied:
                                    type: number
                      top_candidate:
                        type: object
                        nullable: true
                      already_matched:
                        type: boolean
                      note:
                        type: string
                        nullable: true
        '400':
          $ref: '#/components/responses/Error'
        '401':
          $ref: '#/components/responses/Error'
        '403':
          $ref: '#/components/responses/Error'
      security:
        - ApiKeyAuth: []
components:
  responses:
    Error:
      description: Error response (400/401/403/404/409/422/429/500)
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
  schemas:
    ErrorEnvelope:
      type: object
      description: |
        Canonical error response envelope. All API errors use this shape.
      required:
        - error
        - code
      properties:
        error:
          type: string
          description: Machine-readable error key
          example: not_found
        code:
          type: string
          description: Machine-readable error code (often same as error)
          example: not_found
        type:
          type: string
          enum:
            - validation_error
            - permission_error
            - not_found
            - conflict
            - rate_limit
            - internal
            - expand_error
            - not_implemented
          example: not_found
        hint:
          type: string
          description: Human-readable one-sentence explanation (English)
          example: >-
            The requested order does not exist or does not belong to this
            entity.
        param:
          type: string
          description: The parameter that caused the error, if applicable
          example: expand[0]
        required:
          type: string
          description: The scope required (only on insufficient_scope errors)
          example: accounts:read
        request_id:
          type: string
          description: >-
            Unique request ID for support tracing (maps to CloudWatch log
            stream)
          example: req_abc123
  securitySchemes:
    ApiKeyAuth:
      type: http
      scheme: bearer
      description: |
        API key issued per entity via Settings > Developers > API Keys.
        Each key carries scopes (e.g. orders:read, products:write).
        Bearer token format: Authorization: Bearer ark_live_ent_<code>_<random>
        Test keys use ark_test_ent_<code>_<random>. Both are issued per entity
        via Settings > Developers > API Keys.

````