# Integrate Paige with the SAP Business One Service Layer

For developers: the Service Layer calls that turn a Paige invoice into an SAP Business One A/P invoice with the PDF attached — log in, upload the PDF to Attachments2, then POST the PurchaseInvoices document with the attachment entry — fed from Paige's SFTP export files or the Paige API.

Product: paige · Audience: integrator · Time: Half a day for a developer · Last verified: 2026-09-05

Canonical: https://help.ademero.com/paige/integrations/integrate-paige-with-the-sap-business-one-service-layer

**At the end of this guide you'll have the exact Service Layer calls — and the two ways to get Paige's data into them — to create an A/P invoice with the invoice PDF attached for every invoice Paige finishes.**

## Getting Paige's data

| Source | How | When to prefer it |
| --- | --- | --- |
| **SFTP export files** | Paige writes `<name>.pdf` and `<name>.json` per document; your job polls the folder and reads the JSON (`fields`, `metadata.document_type`, `metadata.pdf_file`) | Simplest; the PDF is already assembled |
| **Paige API** | `GET …/scanJobs/{id}/documentPages`, then `…/pages/{pageId}/fieldValues`; page images by signed URL | You'd rather query than watch a folder. The API returns page images, not one merged PDF — see [Integrate your own system with the Paige API](/paige/integrations/integrate-your-own-system-with-the-paige-api). |

The rest assumes you have, per invoice, the field values and the PDF bytes.

## Prerequisite: the attachments folder

The Service Layer can only store attachments in the folder configured under **Administration > System Initialization > General Settings > Path > Attachments Folder**, and the Service Layer process must be able to write there. On a Linux-hosted Service Layer that means the Windows share is mounted; your SAP partner usually sets this up once. Without it, attachment uploads fail.

## Log in

```http
POST https://<server>:50000/b1s/v2/Login
Content-Type: application/json

{ "CompanyDB": "<database>", "UserName": "paige-integration", "Password": "…" }
```

Keep the `B1SESSION` cookie for the calls below; sessions expire after the configured timeout, so re-login on a `401`.

## The calls

### 1. Upload the PDF as an attachment

```http
POST https://<server>:50000/b1s/v2/Attachments2
Content-Type: multipart/form-data; boundary=…

--…
Content-Disposition: form-data; name="files"; filename="INV-20441.pdf"
Content-Type: application/pdf

<raw PDF bytes>
--…--
```

**What you should see:** `201 Created` with an `AbsoluteEntry` — the attachment entry number you'll reference on the invoice.

### 2. Create the A/P invoice referencing it

```http
POST https://<server>:50000/b1s/v2/PurchaseInvoices
Content-Type: application/json

{
  "CardCode": "V00123",
  "DocDate": "2026-08-28",
  "DocDueDate": "2026-09-27",
  "NumAtCard": "INV-20441",
  "DocType": "dDocument_Service",
  "Comments": "Paige – Vendor Invoice",
  "AttachmentEntry": 57,
  "DocumentLines": [
    {
      "AccountCode": "6150",
      "LineTotal": 1284.50,
      "ItemDescription": "Invoice INV-20441"
    }
  ]
}
```

`CardCode` is the vendor's business partner code; look it up first with `GET …/BusinessPartners?$filter=CardName eq 'Acme Office Supply'` if Paige only gives the name. `DocType` `dDocument_Service` posts to G/L accounts (`AccountCode` + `LineTotal`); for item-based invoices use `dDocument_Items` with `ItemCode`, `Quantity`, and `UnitPrice` per line, one per row of Paige's `line_items` table.

**What you should see:** `201 Created` with the new document's `DocEntry` and `DocNum`, and the PDF on the invoice's **Attachments** tab in the SAP client.

## Idempotency and errors

- Before creating, `GET …/PurchaseInvoices?$filter=CardCode eq 'V00123' and NumAtCard eq 'INV-20441'` and skip if one exists.
- Paige's values are strings as printed; format dates as `YYYY-MM-DD` and amounts as numbers.
- Tax and account errors come back as `400` with SAP's message in the body — usually a G/L account not allowed for the vendor's tax group, or a closed posting period.
- If you poll SFTP, move processed files to a `processed/` subfolder; if you poll the Paige API, record processed page IDs.
- `POST …/Logout` when the job finishes.

## What's next

- [Import Paige invoices into SAP Business One with the Data Transfer Workbench](https://help.ademero.com/paige/integrations/import-paige-invoices-into-sap-business-one-with-the-data-transfer-workbench)
- [Integrate your own system with the Paige API](https://help.ademero.com/paige/integrations/integrate-your-own-system-with-the-paige-api)