> ## Documentation Index > Fetch the complete documentation index at: https://docs.useaira.com/llms.txt > Use this file to discover all available pages before exploring further. # Create invoice discount > Creates a manual discount on an invoice. The discount can target the whole invoice, a line item group, or a single line item (via targetIdempotencyKey). ## OpenAPI ````yaml /api-reference/openapi.yaml post /v1/invoices/{invoiceId}/discounts openapi: 3.1.0 info: title: API Reference version: '1.0' description: Aira API Reference x-logo: url: https://static.useaira.com/images/airalogo.svg backgroundColor: '#FFFFFF' altText: Aira Logo servers: - url: https://api.useaira.com description: API base URL security: - ApiKey: [] paths: /v1/invoices/{invoiceId}/discounts: post: tags: - Invoices summary: Create invoice discount description: >- Creates a manual discount on an invoice. The discount can target the whole invoice, a line item group, or a single line item (via targetIdempotencyKey). parameters: - schema: type: string format: uuid in: path name: invoiceId required: true description: The unique identifier of the invoice the discount belongs to. requestBody: content: application/json: schema: type: object properties: target: type: string enum: - invoice - line_item_group - line_item description: >- What the discount applies to: the whole invoice, one line item group, or one line item. targetIdempotencyKey: type: string description: >- The idempotency key of the targeted invoice, line item group, or line item, matching the target field. method: type: string enum: - fixed - percentage description: >- How amount is interpreted: fixed subtracts a monetary amount; percentage subtracts a percentage of the targeted amount. description: type: string minLength: 1 description: Display text of the discount as it appears on the invoice. amount: type: number multipleOf: 1 minimum: 1 description: >- Value of the discount, as a positive integer: whole cents when method is fixed; basis points when method is percentage (1 basis point = 0.01%; maximum 10000 = 100%). required: - target - targetIdempotencyKey - method - description - amount additionalProperties: false required: true description: >- Schema representing a discount on an invoice, on one of its line item groups, or on one of its line items. Only active discounts (see isActive) affect the invoice totals. responses: '201': description: >- Schema representing a discount on an invoice, on one of its line item groups, or on one of its line items. Only active discounts (see isActive) affect the invoice totals. content: application/json: schema: type: object properties: id: type: string format: uuid description: The unique identifier of the discount in our system. target: type: string enum: - invoice - line_item_group - line_item description: >- What the discount applies to: the whole invoice, one line item group, or one line item. targetIdempotencyKey: type: string description: >- The idempotency key of the targeted invoice, line item group, or line item, matching the target field. method: type: string enum: - fixed - percentage description: >- How amount is interpreted: fixed subtracts a monetary amount; percentage subtracts a percentage of the targeted amount. reason: type: string enum: - manual_discount - contract_proration - contract_recurring - plan_instance_proration description: >- Why the discount exists: manual_discount (created by a user or through the API), contract_proration or plan_instance_proration (generated to prorate a partial period), or contract_recurring (generated from a recurring discount configured on the contract). description: type: string minLength: 1 description: Display text of the discount as it appears on the invoice. amount: type: number multipleOf: 1 minimum: 1 description: >- Value of the discount, as a positive integer: whole cents when method is fixed; basis points when method is percentage (1 basis point = 0.01%; maximum 10000 = 100%). isActive: type: boolean description: >- Whether the discount is currently applied to the invoice totals. Inactive discounts are kept for history but have no effect. required: - id - target - targetIdempotencyKey - method - reason - description - amount - isActive additionalProperties: false '400': description: Error object returned to the client. content: application/json: schema: type: object properties: message: type: string description: A human-readable description of the error code: type: string description: A unique identifier for the type of error details: oneOf: - type: object additionalProperties: true - type: array description: >- Additional context about the error, such as invalid fields or constraints. Each endpoint may include specific error details in their documentation causations: type: array description: >- Optional array of error objects following the same structure as the parent error. Only present when there's a meaningful chain of related errors to expose items: type: object properties: message: type: string description: >- A human-readable description of the underlying error cause code: type: string description: A unique identifier for the type of underlying error details: type: object additionalProperties: true description: Additional context about the underlying error required: - message - code additionalProperties: false required: - code - message additionalProperties: false '404': description: Error object returned to the client when a resource is not found. content: application/json: schema: type: object properties: message: type: string description: A human-readable description of the error components: securitySchemes: ApiKey: type: apiKey description: API Key Authentication. name: X-API-KEY in: header ````