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

# Link existing cNGN user id

> Attach an existing wallet user id to the customer and sync. Requires `transfers:write`.



## OpenAPI

````yaml /openapi.yaml post /customers/{id}/strails/link
openapi: 3.1.0
info:
  title: Remitflex API
  version: 1.0.0
  description: >
    Programmatic access to Remitflex payment routes, fiat rates, customers, and
    transactions.


    **Dashboard:** Create API keys at https://dashboard.remitflex.io


    **Authentication:** Send your API key as `Authorization: Bearer
    rmf_live_...` or `rmf_test_...`.


    **Idempotency:** Mutating requests (`POST`, `PUT`, `PATCH`, `DELETE`)
    require an `Idempotency-Key` header when authenticated with an API key.
servers:
  - url: http://localhost:4000/v1
    description: Local development
  - url: https://api.remitflex.io/v1
    description: Production
security:
  - ApiKeyAuth: []
paths:
  /customers/{id}/strails/link:
    post:
      tags:
        - Customers
      summary: Link existing cNGN user id
      description: >-
        Attach an existing wallet user id to the customer and sync. Requires
        `transfers:write`.
      operationId: linkCustomerCngn
      parameters:
        - $ref: '#/components/parameters/IdempotencyKey'
        - name: id
          in: path
          required: true
          schema:
            type: string
            format: uuid
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - strailsUserId
              properties:
                strailsUserId:
                  type: string
      responses:
        '200':
          $ref: '#/components/responses/Customer'
      security:
        - ApiKeyAuth: []
components:
  parameters:
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: true
      description: >-
        Unique key for safe retries on mutating API-key requests. Cached for 24
        hours per org, method, and path.
      schema:
        type: string
        maxLength: 255
        example: 7f3c2a1b-4e5d-6c7b-8a9f-0e1d2c3b4a5f
  responses:
    Customer:
      description: Customer
      content:
        application/json:
          schema:
            allOf:
              - $ref: '#/components/schemas/SuccessEnvelope'
              - type: object
                properties:
                  data:
                    $ref: '#/components/schemas/Customer'
          examples:
            success:
              $ref: '#/components/examples/CreateCustomerResponse'
  schemas:
    SuccessEnvelope:
      type: object
      properties:
        status:
          type: string
          example: success
        message:
          type: string
        data:
          nullable: true
    Customer:
      type: object
      properties:
        id:
          type: string
          format: uuid
        name:
          type: string
        email:
          type: string
        type:
          type: string
        isPrimary:
          type: boolean
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time
  examples:
    CreateCustomerResponse:
      value:
        status: success
        message: Customer created
        data:
          id: b2c3d4e5-f6a7-8901-bcde-f12345678901
          name: Jane Supplier
          email: jane@supplier.co.ke
          type: individual
          isPrimary: false
          createdAt: '2026-06-26T12:00:00.000Z'
          updatedAt: '2026-06-26T12:00:00.000Z'
  securitySchemes:
    ApiKeyAuth:
      type: http
      scheme: bearer
      description: >
        API key created in the Remitflex Dashboard at dashboard.remitflex.io
        (`rmf_live_...` or `rmf_test_...`).

        Key management endpoints require a dashboard JWT and are not part of
        this reference.

````