# Create budget phase

Create a new budget phase for a project

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

## Path parameters:

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

## Request fields (application/json):

  - `name` (string, required)
    Phase name
    Example: "Post-Production"

  - `type` (string, required)
    Phase type
    Enum: "estimate", "actual", "rollup", "committed"

  - `color` (string)
    Phase color for UI display
    Enum: "red", "rose", "pink", "fuchsia", "purple", "violet", "indigo", "blue", "sky", "cyan", "teal", "green", "yellow", "amber", "orange"

  - `currency` (object,null)

  - `currency.code` (string,null)
    Currency code (e.g., USD, EUR)
    Example: "USD"

  - `currency.symbol` (string,null)
    Currency symbol
    Example: "$"

  - `currency.exchangeRate` (number,null)
    Exchange rate multiplier
    Example: 1

  - `copyPhase` (string)
    ID of phase to copy data from
    Example: "estimate"

  - `isHidden` (boolean)
    Whether phase is hidden

  - `phaseIds` (array)
    For rollup phases - IDs of phases to aggregate
    Example: ["estimate","contingency"]

  - `operation` (string)
    For rollup phases - operation to perform
    Enum: "sum", "difference"

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

## Response 201 fields (application/json):

  - `type` (string, required)
    Phase type
    Enum: "estimate", "actual", "rollup", "committed"

  - `id` (string, required)
    Phase system identifier
    Example: "phase-001"

  - `alias` (string, required)
    User-friendly phase alias
    Example: "estimate"

  - `name` (string,null)
    Phase display name
    Example: "Initial Estimate"

  - `isHidden` (boolean, required)
    Whether phase is hidden from view

  - `isLocked` (boolean, required)
    Whether phase is locked from editing

  - `currency` (object,null)
    Currency configuration (for estimate phases)

  - `currency.code` (string,null)
    ISO 4217 currency code
    Example: "USD"

  - `currency.symbol` (string,null)
    Currency symbol
    Example: "$"

  - `currency.exchangeRate` (number,null)
    Exchange rate multiplier
    Example: 1

  - `operation` (string)
    Rollup operation (for rollup phases)
    Enum: "sum", "difference"

  - `phaseIds` (array)
    Phase IDs to aggregate (for rollup phases)
    Example: ["estimate","actual"]

## 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"