Upload a file to Slack using a bot connection and the Make an API Call module

[DanBorn]

Hello Community !

I’m scratching my head over how to upload a JSON file to Slack when using a Bot connection (which can’t use the Upload a file module of Slack app) and the Slack app’s Make an API Call module.

I have tried using a personal connection and the Upload a file module and that works. I create the json using the JSON app and upload it using the module. Works.

But when I’m limited to use a bot connection I’m unable to progress. I’m following Slack’s documentation of the /files.upload endpoint, but I keep getting Error: invalid_form_data (200). from Slack.

Here’s the underlying request captured in Integromat dev tools

And here’s the request which is made from the native Upload a File module - this runs successfully

I’m also attaching the Blueprint of the non-functioning scenario.
blueprint.json (6.7 KB)

Any idea how to format the data for Slack to handle the upload? I can obiously see the discrepancy in the value field, but I have no clue if that’s the core of the problem, nor how to actually get to a value like IMTBuffer.

Cheers! Daniel

[Runcorn]

Hi @DanBorn,

The File Upload API endpoints doesn’t need JSON instead the Content Type that you need to use is multipart/form-data and it seems that Make an API call module for Slack doesn’t support form-data and only allows JSON as part of the request.

[RichardBecker]

Does this mean that the Slack Make an API Request module will never work for files.upload requests?

[DavidGurr_Make]

Yes, but that should only an issue for Bot connections (as in @DanBorn’s original case).

For normal connections, you can use the regular Upload a File module in the Slack app.