/create-type

Create BAML Type

You are tasked with creating a new BAML type definition (class, enum, or type alias).

Task

Create a BAML type as specified in "$ARGUMENTS". Determine the type category and scaffold appropriately.

Steps

1. Parse requirements:

   • Type name
   • Type category (class, enum, or alias)
   • Fields/values
   • Descriptions and constraints
   • Relationships to other types

2. Locate BAML file:

   • Find baml_src/ directory
   • Choose appropriate file or create types.baml
   • Read existing types to avoid conflicts

3. Generate type definition:

   • Write type with proper syntax
   • Add field descriptions
   • Include validation constraints
   • Document usage

4. Add to BAML file:

   • Append to chosen .baml file
   • Ensure proper formatting
   • Show created type

5. Suggest usage:

   • Show how to use in function definitions
   • Provide integration examples
   • Offer to create a function using this type

Example Usage

/baml-toolkit:create-type "Receipt class with vendor, date, items array, total"
/baml-toolkit:create-type "PaymentStatus enum: PENDING, COMPLETED, FAILED, REFUNDED"
/baml-toolkit:create-type "ContactInfo with optional email and phone fields"

Type Categories

Class (Structured Data)

class Receipt {
  vendor string @description("Merchant or business name")
  date string @description("Purchase date in YYYY-MM-DD format")
  items ReceiptItem[] @description("List of purchased items")
  total float @description("Total amount paid")
  tax float?
  tip float?
}

class ReceiptItem {
  name string
  quantity int
  unit_price float
  subtotal float
}

Enum (Fixed Options)

enum PaymentStatus {
  PENDING @description("Payment initiated but not confirmed")
  COMPLETED @description("Payment successfully processed")
  FAILED @description("Payment failed")
  REFUNDED @description("Payment was refunded")
}

enum Priority {
  LOW
  MEDIUM
  HIGH
  URGENT
}

Nested Types

class Order {
  order_id string
  customer CustomerInfo
  items OrderItem[]
  status OrderStatus
  payment PaymentInfo
}

class CustomerInfo {
  name string
  email string
  phone string?
}

class OrderItem {
  product_id string
  name string
  quantity int
  price float
}

enum OrderStatus {
  PENDING
  PROCESSING
  SHIPPED
  DELIVERED
  CANCELLED
}

class PaymentInfo {
  method string
  status PaymentStatus
  amount float
}

Field Types

Primitives:

• string - Text
• int - Integer
• float - Decimal number
• bool - Boolean (true/false)

Collections:

• Type[] - Array of Type
• map<K, V> - Map/dictionary

Optional:

• Type? - Optional field (can be null)

Media:

• image - Image file
• audio - Audio file
• video - Video file

Annotations

class Example {
  field1 string @description("Field purpose")
  field2 int @alias("fieldTwo")
  field3 string? @description("Optional field")
}

Common Patterns

API Response:

class APIResponse {
  success bool
  data APIData?
  error APIError?
}

class APIData {
  // Your data fields
}

class APIError {
  code int
  message string
  details string?
}

Extraction Result:

class ExtractionResult {
  confidence float @description("0.0 to 1.0")
  extracted_data DataType
  metadata ExtractionMetadata
}

Classification:

class ClassificationResult {
  category CategoryEnum
  confidence float
  reasons string[]
}

Notes

• Use descriptive field names (snake_case or camelCase)
• Add @description for clarity
• Use ? for optional fields
• Enums are uppercase by convention
• Classes can be nested arbitrarily deep
• Generated client code will be fully typed