openapi: 3.1.0
info:
  title: Sage Accounting Bank Accounts Purchase Invoices API
  description: 'Sage Accounting API (v3.1) is a RESTful web service that connects software to Sage''s cloud accounting platform. Supports Sage Business Cloud Accounting and Sage Business Cloud Start products. Covers contacts, sales and purchase invoices, payments, bank accounts, ledger accounts, products/services, and financial reporting. Uses OAuth 2.0 for authentication. Rate limits apply: 1,296,000 daily requests, 150 concurrent, 100 per minute per company.'
  version: 3.1.0
  contact:
    name: Sage Developer Support
    url: https://developer.sage.com/support/
  license:
    name: Sage Developer Agreement
    url: https://developer.sage.com/
servers:
- url: https://api.accounting.sage.com/v3.1
  description: Sage Accounting API v3.1
security:
- OAuth2: []
tags:
- name: Purchase Invoices
  description: Purchase invoice and supplier bill management
paths:
  /purchase_invoices:
    get:
      operationId: listPurchaseInvoices
      summary: List Purchase Invoices
      description: Returns a paginated list of purchase invoices (supplier bills).
      tags:
      - Purchase Invoices
      parameters:
      - name: contact_id
        in: query
        schema:
          type: string
      - name: status_id
        in: query
        schema:
          type: string
          enum:
          - DRAFT
          - SENT
          - PAID
          - VOID
      - name: page
        in: query
        schema:
          type: integer
          default: 1
      - name: items_per_page
        in: query
        schema:
          type: integer
          default: 20
      responses:
        '200':
          description: Purchase invoice list
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PurchaseInvoiceList'
    post:
      operationId: createPurchaseInvoice
      summary: Create Purchase Invoice
      description: Creates a new purchase invoice (supplier bill).
      tags:
      - Purchase Invoices
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreatePurchaseInvoiceRequest'
      responses:
        '201':
          description: Purchase invoice created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PurchaseInvoice'
  /purchase_invoices/{key}:
    get:
      operationId: getPurchaseInvoice
      summary: Get Purchase Invoice
      description: Returns a specific purchase invoice by ID.
      tags:
      - Purchase Invoices
      parameters:
      - name: key
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Purchase invoice details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PurchaseInvoice'
components:
  schemas:
    LineItem:
      type: object
      properties:
        id:
          type: string
        description:
          type: string
        quantity:
          type: number
        unit_price:
          type: number
        net_amount:
          type: number
        tax_amount:
          type: number
        total_amount:
          type: number
        ledger_account:
          $ref: '#/components/schemas/LedgerAccountRef'
        tax_rate:
          $ref: '#/components/schemas/TaxRateRef'
    LineItemInput:
      type: object
      required:
      - description
      - quantity
      - unit_price
      - ledger_account_id
      properties:
        description:
          type: string
        quantity:
          type: number
          default: 1
        unit_price:
          type: number
          format: double
        ledger_account_id:
          type: string
        tax_rate_id:
          type: string
    TaxRateRef:
      type: object
      properties:
        id:
          type: string
        displayed_as:
          type: string
    CreatePurchaseInvoiceRequest:
      type: object
      properties:
        purchase_invoice:
          type: object
          required:
          - contact_id
          - date
          - line_items
          properties:
            contact_id:
              type: string
            date:
              type: string
              format: date
            due_date:
              type: string
              format: date
            vendor_reference:
              type: string
            line_items:
              type: array
              items:
                $ref: '#/components/schemas/LineItemInput'
    StatusRef:
      type: object
      properties:
        id:
          type: string
        displayed_as:
          type: string
    ContactRef:
      type: object
      properties:
        id:
          type: string
        displayed_as:
          type: string
    PurchaseInvoiceList:
      type: object
      properties:
        $items:
          type: array
          items:
            $ref: '#/components/schemas/PurchaseInvoice'
        $total:
          type: integer
    PurchaseInvoice:
      type: object
      properties:
        id:
          type: string
        date:
          type: string
          format: date
        due_date:
          type: string
          format: date
        reference:
          type: string
        vendor_reference:
          type: string
        status:
          $ref: '#/components/schemas/StatusRef'
        contact:
          $ref: '#/components/schemas/ContactRef'
        line_items:
          type: array
          items:
            $ref: '#/components/schemas/LineItem'
        net_amount:
          type: number
        tax_amount:
          type: number
        total_amount:
          type: number
        outstanding_amount:
          type: number
    LedgerAccountRef:
      type: object
      properties:
        id:
          type: string
        displayed_as:
          type: string
  securitySchemes:
    OAuth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://www.sageone.com/oauth2/auth
          tokenUrl: https://oauth.accounting.sage.com/token
          scopes:
            full_access: Full read/write access to all accounting data
            readonly: Read-only access to accounting data