Cannot read properties of null (reading 'name') when sending binary file to Whisper API via HTTP

darren1 · June 24, 2025, 8:49am

Hi team,

I’m encountering an issue when sending a binary audio file to my self-hosted Whisper API using the HTTP Request node.

Here’s my setup:

n8n: Self-hosted on Docker (v1.93.0)
Whisper API: Flask-based service running in another Docker container (on port 5000)
Goal: Upload audio file from OneDrive and send it to Whisper for transcription

Postman Test — works fine

When I use Postman to POST to http://<host>:5000/transcribe, everything works. The file is sent as multipart/form-data with the key file.

n8n HTTP Request — error

In n8n, I do this:

I use the OneDrive node to download the .mp3 file into binary field data
Then use HTTP Request node:

Method: POST
Content Type: Form-Data
Body Parameters:
- Parameter Type: n8n Binary File
- Name: file
- Input Data Field Name: data

But I keep getting this error:

pgsql

複製編輯

Cannot read properties of null (reading 'name')

From the execution debug, the binary object exists, and contains the file under data.

I’ve also confirmed the binary field contains the proper metadata (filename, mimeType, fileSize). There are no intermediate nodes removing binary data.

What I’ve tried:

Ensured OneDrive output binary field is called data
Used a Set node with “Include Binary Data” to confirm the file exists
Checked raw execution JSON – binary.data is present
Tried manually specifying another binary field name → same error

Any ideas what could be causing this mismatch, or anything I might be missing in the HTTP Request configuration?

Thanks in advance!