> ## Documentation Index > Fetch the complete documentation index at: https://docs.light.inc/llms.txt > Use this file to discover all available pages before exploring further. # Create contract line > Creates a new contract line item ## OpenAPI ````yaml /openapi-public.json post /v1/contracts/{contractId}/lines openapi: 3.0.1 info: title: Light API version: 1.0.0 servers: [] security: - apiKeyAuth: [] - bearerAuth: [] paths: /v1/contracts/{contractId}/lines: post: tags: - v1 - Contracts summary: Create contract line description: Creates a new contract line item operationId: createContractLine parameters: - name: contractId in: path required: true schema: type: string format: uuid requestBody: content: application/json;charset=UTF-8: schema: $ref: '#/components/schemas/ExternalCreateContractLineRequestV1Model' responses: default: description: default response content: application/json;charset=UTF-8: schema: $ref: '#/components/schemas/ExternalContractLineV1Model' components: schemas: ExternalCreateContractLineRequestV1Model: type: object properties: productId: type: string description: ID of the product format: uuid billingStart: type: string description: Date when billing starts for this line format: date nullable: true billingEnd: type: string description: Date when billing ends for this line format: date nullable: true billingRecurrence: type: string description: >- Billing frequency for this line - `ONE_TIME` - The product is billed once - `MONTHLY` - The product is billed every month - `QUARTERLY` - The product is billed every three months - `HALF_YEARLY` - The product is billed every six months - `YEARLY` - The product is billed every year ⚠️ This enum is not exhaustive; new values may be added in the future. nullable: true deprecated: false enum: - ONE_TIME - MONTHLY - QUARTERLY - HALF_YEARLY - YEARLY accountId: type: string description: ID of the ledger account for this line format: uuid nullable: true taxCodeId: type: string description: ID of the tax code to apply to this line format: uuid nullable: true avataxCode: type: string description: Avalara tax code. Used when the contract tax engine is AVATAX nullable: true discount: $ref: '#/components/schemas/ExternalContractLineDiscountV1Model' quantity: type: number description: Quantity of the product nullable: true priceOverwrite: type: integer description: Custom price override in cents format: int64 nullable: true productNameOverwrite: type: string description: Custom product name override nullable: true customProperties: type: array description: List of custom properties to set on the contract or line nullable: true items: $ref: '#/components/schemas/ExternalSetCustomPropertyRequestV1Model' amortizationTemplateId: type: string description: ID of the amortization template format: uuid nullable: true amortizationStartDate: type: string description: Start date for amortization format: date nullable: true amortizationEndDate: type: string description: End date for amortization format: date nullable: true ExternalContractLineV1Model: type: object properties: id: type: string description: Unique identifier for the object format: uuid companyId: type: string description: ID of the company format: uuid contractId: type: string description: ID of the contract this line belongs to format: uuid productId: type: string description: ID of the product format: uuid billingStart: type: string description: Date when billing starts for this line format: date nullable: true billingEnd: type: string description: Date when billing ends for this line format: date nullable: true billingRecurrence: type: string description: >- Billing frequency for this line - `ONE_TIME` - The product is billed once - `MONTHLY` - The product is billed every month - `QUARTERLY` - The product is billed every three months - `HALF_YEARLY` - The product is billed every six months - `YEARLY` - The product is billed every year ⚠️ This enum is not exhaustive; new values may be added in the future. nullable: false deprecated: false enum: - ONE_TIME - MONTHLY - QUARTERLY - HALF_YEARLY - YEARLY accountId: type: string description: ID of the account for bookkeeping format: uuid nullable: true taxCodeId: type: string description: ID of the tax code format: uuid nullable: true avataxCode: type: string description: Avalara tax code nullable: true discount: $ref: '#/components/schemas/ExternalContractLineDiscountV1Model' quantity: type: number description: Quantity of the product nullable: true priceOverwrite: type: integer description: Custom price override in cents format: int64 nullable: true productNameOverwrite: type: string description: Custom product name override nullable: true amortizationTemplateId: type: string description: ID of the amortization template format: uuid nullable: true amortizationStartDate: type: string description: Start date for amortization format: date nullable: true amortizationEndDate: type: string description: End date for amortization format: date nullable: true aiValueSuggestions: type: array description: AI-generated suggestions for this line nullable: true items: $ref: '#/components/schemas/ExternalAiValueSuggestionV1Model' customProperties: type: array description: List of custom properties associated with the line nullable: true items: $ref: '#/components/schemas/ExternalCustomPropertyV1Model' createdAt: type: string description: Timestamp when the line was created format: date-time updatedAt: type: string description: Timestamp when the line was last updated format: date-time ExternalContractLineDiscountV1Model: type: object properties: startDate: type: string format: date endDate: type: string format: date type: type: string description: >- ⚠️ This enum is not exhaustive; new values may be added in the future. enum: - PERCENTAGE - AMOUNT description: Discount to apply to this line (can be percentage or amount-based) nullable: true discriminator: propertyName: type ExternalSetCustomPropertyRequestV1Model: type: object properties: groupId: type: string description: ID of the custom property group. format: uuid valueIds: type: array description: >- IDs of the selected custom property values. It behaves as a PUT operation, so if empty the existing ones will be effectively deleted. items: type: string description: >- IDs of the selected custom property values. It behaves as a PUT operation, so if empty the existing ones will be effectively deleted. format: uuid inlineValues: type: array description: >- Inline custom property values (used for TEXT/NUMERIC/DATE/etc. groups). It behaves as a PUT operation, so if empty or null the existing ones will be effectively deleted. nullable: true items: type: string description: >- Inline custom property values (used for TEXT/NUMERIC/DATE/etc. groups). It behaves as a PUT operation, so if empty or null the existing ones will be effectively deleted. nullable: true description: >- List of custom properties to set on the vendor. Replaces the existing set. nullable: true ExternalAiValueSuggestionV1Model: type: object properties: field: type: string fieldValues: type: array items: type: string reasoning: type: string description: >- AI-generated suggestions for line item values (e.g. account, cost center, tax code). nullable: true ExternalCustomPropertyV1Model: type: object properties: groupId: type: string description: ID of the custom property group format: uuid groupInternalName: type: string description: Internal name of the custom property group values: type: array description: >- List of values. Note that this will be a single value unless the group input type supports multiple values items: $ref: '#/components/schemas/ExternalCustomPropertyValueV1Model' description: Custom properties set on the vendor. nullable: true ExternalCustomPropertyValueV1Model: type: object properties: id: type: string description: Unique identifier for the object format: uuid groupId: type: string description: ID of the custom property group format: uuid groupInternalName: type: string description: Internal name of the custom property group companyId: type: string description: ID of the company format: uuid internalName: type: string description: Internal name of the custom property value label: type: string description: Label of the custom property value context: type: string description: Context/description of the custom property value nullable: true createdAt: type: string description: Timestamp when the custom property value was created format: date-time updatedAt: type: string description: Timestamp when the custom property value was last updated format: date-time description: >- List of values. Note that this will be a single value unless the group input type supports multiple values securitySchemes: apiKeyAuth: type: apiKey description: >- Basic authentication header of the form **Basic** ****, where **** is your api key. name: Authorization in: header bearerAuth: type: http scheme: bearer bearerFormat: JWT ````