How to download invoice PDFs from Xero

The Apideck Accounting unified API doesn't expose invoice PDF download as a unified operation, but you can retrieve them via the Proxy API. This guide shows how to do this for Xero.

The flow is two steps: use the unified GET /accounting/invoices endpoint to find the invoice you want, then use its id in a Proxy API call to download the PDF.

Xero's invoice endpoint serves both JSON and PDF off the same URL - only the Accept header changes the response type.

• An active Apideck Vault connection for Xero (service-id: xero)

• The Apideck consumer-id, app-id, and api-key

• An invoice in Xero with a status of SUBMITTED, AUTHORISED, or PAID (drafts cannot be rendered as PDF)

• The invoice must be of type ACCREC (accounts receivable). ACCPAY invoices don't support PDF rendering via the API.

Use the unified Accounting API to list invoices and find the one you want:

curl --location 'https://unify.apideck.com/accounting/invoices' \
  --header 'Authorization: Bearer {APIDECK_API_KEY}' \
  --header 'x-apideck-app-id: {APP_ID}' \
  --header 'x-apideck-consumer-id: {CONSUMER_ID}' \
  --header 'x-apideck-service-id: xero'

The response contains an array of invoices. Copy the id of the invoice you want as a PDF - you'll use it in the next step. The unified id is the same as Xero's InvoiceID GUID.

curl --location 'https://unify.apideck.com/proxy' \
  --header 'Authorization: Bearer {APIDECK_API_KEY}' \
  --header 'x-apideck-app-id: {APP_ID}' \
  --header 'x-apideck-consumer-id: {CONSUMER_ID}' \
  --header 'x-apideck-service-id: xero' \
  --header 'x-apideck-downstream-url: https://api.xero.com/api.xro/2.0/Invoices/{INVOICE_ID}' \
  --header 'Accept: application/pdf' \
  --output xero-invoice.pdf

The Apideck Proxy detects the binary response and base64-encodes it internally; API Gateway decodes it back to raw bytes before delivery, so your HTTP client receives a normal PDF binary.

Draft invoices won't render. Xero only generates PDFs for invoices in SUBMITTED, AUTHORISED, or PAID status. If you call the endpoint for a draft, you'll get a JSON error response instead of a PDF. To fix it, transition the invoice to one of the renderable statuses first.

The same URL serves JSON and PDF. If you accidentally send Accept: application/json (or no Accept header), you'll get the invoice's JSON representation back. Always set Accept: application/pdf explicitly.

• What does passthrough or Proxy API mean?