sending webhook by url attachement

[Martial_Lanoue]

Hello,
I have weird behavior when sending a webhook.
For this project, I am working on a free airtable space. So I can't use scripts.
This is a table in which I have large images. I want to reduce them (basically, go from 3-4 MB to 150 KB).
I have a Make scenario which is fine except that it receives the duplicate webhook and therefore triggers twice.
In Airtable, I have an automation that will copy a webhook into an attachment field to launch the webhook
the trigger: when the “Image” field is updated
the webhook: a formula = WH Make & record ID Airtable & a timestamp of the modified las (without the timestamp, the WH is always identical and Airtable only triggers it the first time)
When I modify the image, the autom airtable only fires once, but Make receives 2 webhooks
Anyone have any idea why? (and a solution)

[Sachin_191 · Accepted solution]

Let's address your webhook issue and image resizing challenge. For the webhook duplication, it seems that Airtable's timestamp update is causing Make to trigger twice. We can modify the scenario to filter out duplicate webhooks based on unique identifiers or timestamps, ensuring only one instance proceeds. For image resizing, we can use an external API like TinyPNG within Make to reduce image sizes efficiently.

[Martial_Lanoue]

Thank you Sachin for the response
I have no problem with Make and the resizing scenario (I use Make's Image Resize module). It works well (twice ;-))
I have indeed filtered the 2nd webhook in the Make scenario but I would prefer that the webhook be sent only once to only trigger the scenario once.
At the end of my webhook, I send the last modified timestamp (I tried with the Now timestamp as well). Webhooks are still sent twice
Otherwise, I don't understand what timestamp you are talking about, could you explain, please

[kuovonne]

Copying the webhook url to an attachment field is an unusual way of calling the webhook. I’m guessing that Airtable is trying to get an attachment at the url multiple times before giving up.

Since you are on the free plan, you only get 100 automation runs per month. How many images do you need to process and does the webhook need to be called automatically?

If you need to stay on the free plan, why not put the url in a button field and have a human click the button? Clicking 100 buttons is kinda annoying, but if you don’t have budget to pay in money, you have to expect to pay in labor.

Another option if you are processing records in batches is to have Make search for records instead of using an Airtable automation. You could trigger this webhook with a human clicking a single button. Then the scenario searches for records that need to be processed, and then processed them in a batch. 

[Martial_Lanoue]

Thanks for your answer
I know that it is not "normal" operation to use an attachment field to launch webhooks
I'm using Airtable as a back end for a mobile app and the user doesn't have access to Airtable. the 100 executions are not a problem, I am mainly looking to make the experience easier for him through his mobile thanks to another tool (because airtable is rather bad on mobile).
It is preferable that the scenario launches with each modification live rather than in batches.
I came to the same conclusion that Airtable tries to access several times but there are 2 things that still surprise me:
- 15 days ago, only one webhook was launched
- it is systematically 2 webhooks from now on (never 1 nor 3)

Too bad, I would have liked to understand how it works a little better.

[Martial_Lanoue]

I didn't know tinypng, thanks for the discovery 👍

[kuovonne]

The number of attempts that Airtable makes to obtain an attachment is not documented and is not guaranteed to be static. The number of attempts and the time between attempts could change whenever Airtable wants.