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

# Change a purchase order's lines

> Adds or changes lines on a purchase order and returns it under `purchase_order`.

Changes the lines of the purchase order, wrapped in `purchase_order.lines`. Each entry has an `op`: `add` with an `item_id` and `item_quantity` adds a line, and `change` with the line's `id` written as a UUID (drop the prefix before `_` and add dashes in the 8-4-4-4-12 pattern) changes its quantity or price.

> [!NOTE]
>
> The SDK samples get their client from credentials your app registers once when it starts, as shown in [Authentication](https://exsited.mintlify.site/authentication.md#set-up-a-client). To try the call here, click **Try it**, set `host` to your Exsited API host name and paste an access token from [Get an access token](https://exsited.mintlify.site/api-reference/authentication/get-an-access-token.md). To send a raw JSON body instead of filling in fields, copy the cURL sample and edit its `-d` payload.


## OpenAPI

````yaml POST /purchase_orders/{purchase_order_id}/change
openapi: 3.1.0
info:
  title: Exsited API
  version: v4
servers:
  - url: https://{host}/api/v4
    variables:
      host:
        default: your-api-host.example.com
        description: Your Exsited API host name, without https://.
security:
  - bearerAuth: []
tags:
  - name: Authentication
  - name: Accounts
  - name: Account emails
  - name: Account groups
  - name: Communications
  - name: Communication profiles
  - name: Orders
  - name: Quote orders
  - name: Express
  - name: Usages
  - name: Sales reps
  - name: Gift certificates
  - name: Invoices
  - name: Pro-forma invoices
  - name: Payments
  - name: Refunds
  - name: Credit notes
  - name: Credit note applications
  - name: Reconciliations
  - name: Items
  - name: Inventory adjustments
  - name: Units of measurement
  - name: Zones
  - name: Shipping packages
  - name: Shipping rules
  - name: Fulfillment profiles
  - name: Fulfillment terms
  - name: Item fulfillments
  - name: Item receipts
  - name: Bookings
  - name: Rental assets
  - name: Return merchandise authorisations
  - name: Purchase orders
  - name: Purchase invoices
  - name: Purchase payments
  - name: Purchase refunds
  - name: Purchase credit notes
  - name: Purchase credit note applications
  - name: Purchase express
  - name: Return vendor authorizations
  - name: ABA files
  - name: Receive terms
  - name: Labours
  - name: Tasks
  - name: Timesheets
  - name: Milestones
  - name: Employees
  - name: Departments
  - name: Designations
  - name: Teams
  - name: Time periods
  - name: Workflows
  - name: Workflow settings
  - name: Events
  - name: Custom events
  - name: System events
  - name: Approvals
  - name: Approval profiles
  - name: Approval user groups
  - name: Alerts
  - name: Alert responsibility settings
  - name: Alert responsibilities
  - name: Action scripts
  - name: Note groups
  - name: Note attachments
  - name: Instance settings
  - name: Accounting codes
  - name: Additional codes
  - name: Billing periods
  - name: Charging periods
  - name: Pricing periods
  - name: Invoice terms
  - name: Days of the month
  - name: Countries
  - name: Salutations
  - name: Document templates
  - name: Email templates
  - name: Roles
  - name: Operators
  - name: Operator groups
  - name: User settings
  - name: Custom attributes
  - name: Custom components
  - name: Custom features
  - name: Custom fields
  - name: Custom forms
  - name: Attribute attachments
  - name: Portal
  - name: Integration connections
  - name: External databases
  - name: Reports
  - name: Applications
  - name: Organisation
  - name: Child organisations
  - name: Webhooks
paths:
  /purchase_orders/{purchase_order_id}/change:
    post:
      tags:
        - Purchase orders
      summary: Change a purchase order's lines
      description: >-
        Changes the lines of the purchase order, wrapped in
        `purchase_order.lines`. Each entry has an `op`: `add` with an `item_id`
        and `item_quantity` adds a line, and `change` with the line's `id`
        written as a UUID (drop the prefix before `_` and add dashes in the
        8-4-4-4-12 pattern) changes its quantity or price.
      operationId: purchase_orders_change_purchase_order
      parameters:
        - name: purchase_order_id
          in: path
          required: true
          description: The purchase order's `id`.
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                purchase_order:
                  type: object
                  properties:
                    lines:
                      type: array
                      items:
                        type: object
                        properties:
                          op:
                            type: string
                            description: '`add` to add a line, or `change` to change one.'
                            enum:
                              - add
                              - change
                          uuid:
                            type: string
                            description: >-
                              For `change`: the line's `id` written as a UUID:
                              drop the prefix before `_` and add dashes in the
                              8-4-4-4-12 pattern.
                          item_id:
                            type: string
                            description: 'For `add`: the `id` of the item to add.'
                          item_quantity:
                            type: number
                          item_price_snapshot:
                            type: object
                            properties:
                              pricing_rule:
                                type: object
                                properties:
                                  price:
                                    type: number
                        required:
                          - op
              required:
                - purchase_order
            example:
              purchase_order:
                lines:
                  - op: add
                    item_id: ITEM-0001
                    item_quantity: 1
      responses:
        '200':
          description: The changed purchase order, under `purchase_order`.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PurchaseOrderResponse'
      x-codeSamples:
        - lang: bash
          label: cURL
          source: >-
            curl -X POST
            "$EXSITED_BASE_URL/api/v4/purchase_orders/PURCHASE_ORDER_ID/change"
            \
              -H "Authorization: Bearer $ACCESS_TOKEN" \
              -H "Content-Type: application/json" \
              -d '{
                "purchase_order": {
                  "lines": [
                    {
                      "op": "add",
                      "item_id": "ITEM-0001",
                      "item_quantity": 1
                    }
                  ]
                }
              }'
        - lang: python
          label: Python
          source: |
            from exsited import build_client

            client = build_client()

            response = client.purchase_orders.change_purchase_order(
                "PURCHASE_ORDER_ID",
                {
                    "purchase_order": {
                        "lines": [{"op": "add", "item_id": "ITEM-0001", "item_quantity": 1}]
                    }
                },
            )
            print(response.data)
        - lang: javascript
          label: JavaScript
          source: >
            import {buildClient} from 'exsited';


            const client = await buildClient();


            const response = await
            client.purchaseOrders.changePurchaseOrder('PURCHASE_ORDER_ID', {
                purchase_order: {lines: [{op: 'add', item_id: 'ITEM-0001', item_quantity: 1}]},
            });

            console.log(response.data);
        - lang: php
          label: PHP
          source: >
            use Exsited\Client\ClientRegistry;


            $client = ClientRegistry::buildClient();


            $response =
            $client->purchaseOrders->changePurchaseOrder('PURCHASE_ORDER_ID', [
                'purchase_order' => [
                    'lines' => [['op' => 'add', 'item_id' => 'ITEM-0001', 'item_quantity' => 1]],
                ],
            ]);

            print_r($response->data);
        - lang: java
          label: Java
          source: >
            import com.exsited.client.ApiResponse;

            import com.exsited.client.ClientRegistry;

            import com.exsited.client.ExsitedClient;

            import
            com.exsited.resources.purchase_orders.purchase_orders_dto.PurchaseOrdersDto.PurchaseOrderRead;

            import java.util.List;

            import java.util.Map;


            ExsitedClient client = ClientRegistry.buildClient();


            ApiResponse<PurchaseOrderRead> response =
            client.purchaseOrders().changePurchaseOrder(
                    "PURCHASE_ORDER_ID",
                    Map.of(
                            "purchase_order", Map.of(
                                    "lines", List.of(
                                            Map.of("op", "add", "item_id", "ITEM-0001", "item_quantity", 1)))));
            System.out.println(response.getMap());
        - lang: csharp
          label: .NET
          source: |
            using Exsited.Client;

            await using var client = ExsitedClient.BuildClient();

            var response = await client.PurchaseOrders.ChangePurchaseOrderAsync(
                "PURCHASE_ORDER_ID",
                new Dictionary<string, object?>
                {
                    ["purchase_order"] = new Dictionary<string, object?>
                    {
                        ["lines"] = new List<object?>
                        {
                            new Dictionary<string, object?>
                            {
                                ["op"] = "add",
                                ["item_id"] = "ITEM-0001",
                                ["item_quantity"] = 1,
                            },
                        },
                    },
                });

            Console.WriteLine(response.Json);
        - lang: dart
          label: Dart
          source: |
            import 'package:exsited/exsited.dart';

            final client = buildClient();

            final response = await client.purchaseOrders.changePurchaseOrder(
              'PURCHASE_ORDER_ID',
              {
                'purchase_order': {
                  'lines': [
                    {'op': 'add', 'item_id': 'ITEM-0001', 'item_quantity': 1},
                  ],
                },
              },
            );
            print(response.map);
        - lang: go
          label: Go
          source: "import (\n\t\"context\"\n\t\"fmt\"\n\t\"log\"\n\n\texsited \"github.com/exsited/exsited-sdk-go/v4\"\n)\n\nclient, err := exsited.BuildClient(nil)\nif err != nil {\n\tlog.Fatal(err)\n}\ndefer client.Close()\n\nresponse, err := client.PurchaseOrders().ChangePurchaseOrder(context.Background(), \"PURCHASE_ORDER_ID\", map[string]any{\n\t\"purchase_order\": map[string]any{\n\t\t\"lines\": []any{\n\t\t\tmap[string]any{\n\t\t\t\t\"op\":            \"add\",\n\t\t\t\t\"item_id\":       \"ITEM-0001\",\n\t\t\t\t\"item_quantity\": 1,\n\t\t\t},\n\t\t},\n\t},\n}, nil)\nif err != nil {\n\tlog.Fatal(err)\n}\nfmt.Println(response.Map)\n"
components:
  schemas:
    PurchaseOrderResponse:
      type: object
      properties:
        purchase_order:
          $ref: '#/components/schemas/PurchaseOrderRead'
    PurchaseOrderRead:
      type: object
      properties:
        account:
          $ref: '#/components/schemas/PurchaseOrderReadAccount'
        activity_logs:
          type: array
          items: {}
        bill_total:
          type: string
        code:
          type: string
        created_by:
          $ref: '#/components/schemas/PurchaseOrderReadCreatedBy'
        created_on:
          type: string
        currency:
          $ref: '#/components/schemas/PurchaseOrderReadCurrency'
        custom_attributes:
          type: array
          items:
            $ref: '#/components/schemas/PurchaseOrderReadCustomAttribute'
        custom_form:
          $ref: '#/components/schemas/PurchaseOrderReadCustomForm'
        due_date:
          type: string
        due_total:
          type: string
        expected_completion_date:
          type: string
        href:
          type: string
        id:
          type: string
        is_price_tax_inclusive:
          type: boolean
        issue_date:
          type: string
        kpis:
          $ref: '#/components/schemas/PurchaseOrderReadKpis'
        last_updated_by:
          $ref: '#/components/schemas/PurchaseOrderReadLastUpdatedBy'
        last_updated_on:
          type: string
        object:
          type: string
        operational_status:
          type: string
        origin:
          type: string
        paid_amount:
          type: string
        purchase_order_note:
          type: string
        sale_order: {}
        status:
          type: string
        subtotal:
          type: string
        supplier_invoice_id:
          type: string
        tax_total:
          type: string
        total:
          type: string
        version:
          type: integer
        warehouse: {}
    PurchaseOrderReadAccount:
      type: object
      properties:
        code:
          type: string
        href:
          type: string
        id:
          type: string
        name:
          type: string
        object:
          type: string
    PurchaseOrderReadCreatedBy:
      type: object
      properties:
        name:
          type: string
        object:
          type: string
    PurchaseOrderReadCurrency:
      type: object
      properties:
        code:
          type: string
        href:
          type: string
        id:
          type: string
        name:
          type: string
        object:
          type: string
    PurchaseOrderReadCustomAttribute:
      type: object
      properties:
        href:
          type: string
        id:
          type: string
        name:
          type: string
        object:
          type: string
        type:
          type: string
        value:
          type: string
    PurchaseOrderReadCustomForm:
      type: object
      properties:
        object:
          type: string
        id:
          type: string
        name:
          type: string
        href:
          type: string
    PurchaseOrderReadKpis:
      type: object
      properties:
        estimated_total:
          type: string
        issue_date: {}
        last_cancelled_on: {}
        last_changed_on: {}
        last_deleted_on: {}
        last_invoice_issue_date: {}
        last_invoice_total:
          type: string
        last_reactivated_on: {}
        object:
          type: string
        total_expense:
          type: string
        total_outstanding:
          type: string
        total_overdue:
          type: string
        total_purchase_invoice:
          type: integer
    PurchaseOrderReadLastUpdatedBy:
      type: object
      properties:
        name:
          type: string
        object:
          type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        An access token from `POST /api/v4/oauth2/token`. The SDKs get and renew
        it for you.

````

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