> ## Documentation Index > Fetch the complete documentation index at: https://docs.dimepayments.com/llms.txt > Use this file to discover all available pages before exploring further. # Add Line Item > Appends a single line item to a draft invoice and recalculates totals. ## OpenAPI ````yaml https://app.dimepayments.com/openapi.yaml post /api/invoice/line-item/add openapi: 3.0.3 info: title: Dime Payments API Documentation description: >- A simple, basic API for managing Merchants through Dime Payments. JSON based REST API version: 1.0.0 servers: - url: https://app.dimepayments.com security: - default: [] tags: - name: Merchant management description: '' - name: Transaction management description: >- APIs for managing transactions. Depending on API KEY permissions, one should be able to charge credit cards, ACH, Google/Apple Pay wallets along with other functions. - name: Addresses description: |- APIs for managing customer addresses - name: Customer management description: >- APIs for managing customers. Depending on API KEY permissions, one should be able to list, create, update, and delete customers along with several other customer specific requests. - name: Deposit management description: '' - name: Invoice management description: >- APIs for managing invoices. Depending on API KEY permissions, one should be able to list, create, update, delete, and send invoices, manage their line items, and manage recurring-invoice schedules. Every request is scoped to a single Merchant via the required `data.sid`. - name: Payment Method management description: >- APIs for managing payment methods associated with customers. Depending on API KEY permissions, one should be able to list, show, create, update, and delete payment methods. - name: Recurring Payments management description: >- APIs for managing recurring payments. Depending on API KEY permissions, one should be able to create, edit, pause, cancel along with other functions. - name: Zapier description: >- APIs for use through Zapier. Depending on API KEY permissions, one should be able to see customers and transactions data. paths: /api/invoice/line-item/add: post: tags: - Invoice management summary: Add Line Item description: Appends a single line item to a draft invoice and recalculates totals. operationId: addLineItem parameters: [] requestBody: required: false content: application/json: schema: type: object properties: data: type: object description: '' example: sid: 12345 properties: sid: type: integer description: The SID of the Merchant. example: 12345 invoice_id: type: integer description: The id of the draft invoice. example: 42 item_id: type: integer description: The Merchant item id this line is sourced from. example: 5 name: type: string description: The line name. example: Consulting description: type: string description: An optional line description. example: 2 hours quantity: type: number description: The quantity. example: 2 unit_price: type: number description: The unit price in dollars. example: 125 required: - sid - invoice_id - item_id - name - quantity - unit_price responses: '200': description: '' content: application/json: schema: type: object example: data: id: null token: ZZtkx6kulWXLhTL2zXeoZX4Y8diKPpDCiaeixPS1 invoice_number: INV-93082 status: draft payment_terms: net_15 issue_date: '2026-07-20' due_date: '2026-08-04' is_overdue: false subtotal: 0 total: 0 amount_paid: 0 balance: 0 allow_partial_payment: true thank_you_note: null public_url: >- http://app.dimepayments.com/invoice/ZZtkx6kulWXLhTL2zXeoZX4Y8diKPpDCiaeixPS1 customer: id: 15127 name: Mina Bauch email: okeefe.isidro@example.org items: [] payments: [] events: [] properties: data: type: object properties: id: type: string example: null nullable: true token: type: string example: ZZtkx6kulWXLhTL2zXeoZX4Y8diKPpDCiaeixPS1 invoice_number: type: string example: INV-93082 status: type: string example: draft payment_terms: type: string example: net_15 issue_date: type: string example: '2026-07-20' due_date: type: string example: '2026-08-04' is_overdue: type: boolean example: false subtotal: type: integer example: 0 total: type: integer example: 0 amount_paid: type: integer example: 0 balance: type: integer example: 0 allow_partial_payment: type: boolean example: true thank_you_note: type: string example: null nullable: true public_url: type: string example: >- http://app.dimepayments.com/invoice/ZZtkx6kulWXLhTL2zXeoZX4Y8diKPpDCiaeixPS1 customer: type: object properties: id: type: integer example: 15127 name: type: string example: Mina Bauch email: type: string example: okeefe.isidro@example.org items: type: array example: [] payments: type: array example: [] events: type: array example: [] '400': description: Failed validation content: application/json: schema: type: object example: errors: data.item_id: - The selected data.item id is invalid. properties: errors: type: object properties: data.item_id: type: array example: - The selected data.item id is invalid. items: type: string '401': description: Token unauthorized content: application/json: schema: type: object example: data: message: Permission Denied. properties: data: type: object properties: message: type: string example: Permission Denied. '404': description: '' content: application/json: schema: oneOf: - description: Invalid sid type: object example: data: message: No such Merchant properties: data: type: object properties: message: type: string example: No such Merchant - description: Invoice not found type: object example: data: message: Invoice not found properties: data: type: object properties: message: type: string example: Invoice not found '422': description: Invoice locked content: application/json: schema: type: object example: data: message: Only draft invoices can be edited. properties: data: type: object properties: message: type: string example: Only draft invoices can be edited. components: securitySchemes: default: type: http scheme: bearer description: >- You can retrieve your token by visiting your dashboard and clicking Generate API token under your profile in top right. ````