# Add Rate to Rate Card

Associate a rate with a rate card (idempotent)

Endpoint: POST /rateCards/{rateCardId}/rates/{rateId}
Version: 1.0.0
Security: OAuth2

## Path parameters:

  - `rateCardId` (string, required)
    Unique identifier for the rate card

  - `rateId` (string, required)
    Unique identifier for the rate

## Request fields (application/json):

  - `displayOrder` (integer)
    Order in which rate appears in the card (lower = first)

## Response 201 fields (application/json):

  - `rateCardId` (string, required)

  - `rateId` (string, required)

  - `displayOrder` (integer)

  - `createdAt` (string, required)

## Response 401 fields (application/json):

  - `result` (object, required)

  - `result.status` (string, required)
    Response status (always ERROR for error responses)
    Enum: "ERROR"

  - `error` (object, required)

  - `error.responseCode` (string, required)
    Response code (numeric or contains numbers, e.g., "404", "409", "500", "ERR001")
    Example: "404"

  - `error.responseMessage` (array, required)
    Array of error message strings for multiple error details
    Example: ["Charge not found","The requested charge ID does not exist in the system"]

## Response 404 fields (application/json):

  - `result` (object, required)

  - `result.status` (string, required)
    Response status (always ERROR for error responses)
    Enum: "ERROR"

  - `error` (object, required)

  - `error.responseCode` (string, required)
    Response code (numeric or contains numbers, e.g., "404", "409", "500", "ERR001")
    Example: "404"

  - `error.responseMessage` (array, required)
    Array of error message strings for multiple error details
    Example: ["Charge not found","The requested charge ID does not exist in the system"]