Downloading File from Slack only returns HTML in HTTP Request Node

[ericgr]

Trying to download PDF file posted to slack to pass to LLM

No error. But when I try to use the HTTP Request Node to get the file (from the URL after it was added to Slack), it only returns HTML. I have added the Response option and set it to “file”. This makes a binary file, but the file is still HTML and NOT the PDF. If I can get the PDF, I would upload it to OpenAI to provide a summary.

Is this even the correct way to go about getting a file from Slack?

Please share your workflow

Share the output returned by the last node

Information on your n8n setup

• n8n version: 1.83.2
• Database (default: SQLite): SQLite
• n8n EXECUTIONS_PROCESS setting (default: own, main):
• Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
• **Operating system: **

[Franz]

You have to use to Slack node with Get File operation.
Using the HTTP node downloads the Auth / Login page of slack.

[ericgr]

Thank you @Franz . I’ve added a Get File slack node. Interestingly, it still seems to provide the same format as the Slack Trigger, in that it provides URLs, but not an actual binary file. That was why I introduced the HTTP Request Node. Here are some updated images.

Overall flow so far:

Results of Slack Trigger:

Results of Slack ‘Get File’:

For the sake of context, the Edit Fields node is there because I also need to capture the message from slack and use it, as well, when I pass the PDF to the LLM.

So, while I can “get” URLs of the file in Slack, I still don’t seem to be able to download it into n8n.

Thank you!

[Franz]

Unfortunately, this is not possible with the Slack node directly.
However, the HTTP node does allow you to use the same credentials. It works when using Slack OAuth2 API credentials.

[ericgr]

Thanks, again. I just got it working correctly with the HTTP Node. The issue was the URL that was using was incorrect.

I was able to use this directly from the Slack trigger node: