# Create budget fringe

Create a new fringe benefit for a project

Endpoint: POST /projects/{projectId}/budget/fringes
Version: 1.0.0
Security: ApiKeyAuth

## Path parameters:

  - `projectId` (string, required)
    Project identifier (alias or ID)
    Example: "nike-spring-2024"

## Request fields (application/json):

  - `code` (string, required)
    Fringe code/symbol
    Example: "FICA"

  - `description` (string)
    Fringe description
    Example: "Social Security Tax"

  - `units` (string, required)
    Fringe calculation units
    Enum: "percent", "flat"

  - `rate` (number, required)
    Fringe rate (decimal for percent, amount for flat)
    Example: 0.062

  - `cutoff` (number,null)
    Salary cutoff limit
    Example: 160200

  - `idMode` (string)
    ID interpretation mode - "user" for human-friendly IDs (default), "system" for database IDs
    Enum: "user", "system"

## Response 201 fields (application/json):

  - `id` (string, required)
    Fringe system identifier
    Example: "fringe-001"

  - `code` (string,null)
    User-friendly fringe code
    Example: "FICA"

  - `description` (string,null)
    Fringe benefit description
    Example: "Social Security Tax"

  - `units` (string, required)
    Fringe calculation units
    Enum: "percent", "flat"

  - `rate` (number,null)
    Fringe rate (decimal for percent, amount for flat)
    Example: 0.0765

  - `cutoff` (number,null)
    Maximum salary subject to this fringe
    Example: 160200

## Response 400 fields (application/json):

  - `error` (string, required)
    Error message
    Example: "Invalid request parameters"

  - `details` (object)
    Additional error details
    Example: {"field":"projectId","reason":"Project not found"}

  - `code` (string)
    Error code
    Example: "VALIDATION_ERROR"

## Response 401 fields (application/json):

  - `error` (string, required)
    Error message
    Example: "Invalid request parameters"

  - `details` (object)
    Additional error details
    Example: {"field":"projectId","reason":"Project not found"}

  - `code` (string)
    Error code
    Example: "VALIDATION_ERROR"

## Response 404 fields (application/json):

  - `error` (string, required)
    Error message
    Example: "Invalid request parameters"

  - `details` (object)
    Additional error details
    Example: {"field":"projectId","reason":"Project not found"}

  - `code` (string)
    Error code
    Example: "VALIDATION_ERROR"

## Response 500 fields (application/json):

  - `error` (string, required)
    Error message
    Example: "Invalid request parameters"

  - `details` (object)
    Additional error details
    Example: {"field":"projectId","reason":"Project not found"}

  - `code` (string)
    Error code
    Example: "VALIDATION_ERROR"