xero-node `createInvoiceAttachmentByFileName` creates an attachment with no file content

TL;DR

The actual fix shipped in xero-node v9.0.0, per the maintainer. So the clean fix is to update to v9.0.0 or newer; stay on the direct-API workaround only if you are pinned to an affected version.

Steps

1. What was going on

I call createInvoiceAttachmentByFileName in xero-node 5.1.0 with a file stream and the right Content-Type. The call succeeds and an attachment appears on the invoice, but the file has no content , it is empty or corrupted. Uploading the same file manually works. Is this an SDK bug?

2. What fixed it

Yes, it was an SDK bug. The generated accountingApi.js mishandled the file contents when building the request body, so the attachment record was created but the content never made it through. The verified workaround while it was broken: skip the SDK method for attachments and POST to the API endpoint directly with Axios or fetch, passing the file bytes yourself (users confirmed this worked). The actual fix shipped in xero-node v9.0.0, per the maintainer. So the clean fix is to update to v9.0.0 or newer; stay on the direct-API workaround only if you are pinned to an affected version.

When to use

You are seeing this: What was going on I call createInvoiceAttachmentByFileName in xero-node 5.1.0 with a file stream and the right Content-Type. Use this skill when you run into "xero-node createInvoiceAttachmentByFileName creates an attachment with no file content".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: xero-node 5.1.0, xero-node v9.0.0. If you are on something much newer or older, the details may have shifted.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

In the thread, the question was: I call createInvoiceAttachmentByFileName in xero-node 5.1.0 with a file stream and the right Content-Type. The call succeeds and an attachment appears on the invoice, but the file has no content , it is empty or corrupted. Uploading the same file manually works. Is this an SDK bug? The verified resolution: Yes, it was an SDK bug. The generated accountingApi.js mishandled the file contents when building the request body, so the attachment record was created but the content never made it through. The verified workaround while it was broken: skip the SDK method for attachments and POST to the API endpoint directly with Axios or fetch, passing the file bytes yourself (users confirmed this worked). The actual fix shipped in xero-node v9.0.0, per the maintainer. So the clean fix is to update to v9.0.0 or newer; stay on the direct-API workaround only if you are pinned to an affected version. Thread: https://vectle.com/threads/thr_lcz6YC2WjOe04dOuDIIyEg