> ## Documentation Index
> Fetch the complete documentation index at: https://docs.antei.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Invoice

> Create a new invoice with line items, contact, currency, and issue date.

This endpoint allows you to generate a new invoice.

Required fields:

* `contact_id`
* `line_items` with product references
* `currency` and `issue_date`

You may also include optional fields such as `due_date`, `payment_instructions`, or `internal_notes`.

Once created, the invoice will be available for downstream tax calculation, email dispatch, and reporting workflows.


## OpenAPI

````yaml POST /invoices
openapi: 3.0.1
info:
  title: Antei API Reference
  description: >-
    Programmatic access to Antei’s platform. Use this API to manage core objects
    and retrieve taxation insights.
  version: 1.0.0
  license:
    name: MIT
  contact:
    name: Antei Developer Support
    email: support@antei.com
    url: https://antei.com
servers:
  - url: https://api.antei.com
security:
  - bearerAuth: []
paths:
  /invoices:
    post:
      summary: Create an invoice
      description: >-
        Create a new invoice and associate it with contacts, products, taxes,
        and payment instructions.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/NewInvoice'
      responses:
        '201':
          description: Invoice created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Invoice'
components:
  schemas:
    NewInvoice:
      type: object
      properties:
        contact_id:
          type: string
        line_items:
          type: array
          items:
            type: object
            properties:
              product_id:
                type: string
              quantity:
                type: integer
              price:
                type: number
            required:
              - product_id
              - quantity
              - price
        issue_date:
          type: string
          format: date
        due_date:
          type: string
          format: date
        currency:
          type: string
        metadata:
          type: object
          additionalProperties:
            type: string
      required:
        - contact_id
        - line_items
        - currency
    Invoice:
      type: object
      properties:
        id:
          type: string
        invoice_number:
          type: string
        status:
          type: string
          enum:
            - draft
            - sent
            - paid
            - void
        contact_id:
          type: string
        transaction_ids:
          type: array
          items:
            type: string
        currency:
          type: string
        amount:
          type: number
          format: float
        issue_date:
          type: string
          format: date
        due_date:
          type: string
          format: date
        metadata:
          type: object
          additionalProperties:
            type: string
      required:
        - invoice_number
        - contact_id
        - status
        - currency
        - amount
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````