Can you tell who is watching a particular card?
Asked by Barry Hus:

As the admin of a board can you see who all is watching cards within the project?


Answers:
author: Iain Dooley
body: [@Barry Hus](/t5/user/viewprofilepage/user-id/2836754) nope, not even with the API. You can see a list of card members, but not a list of card watchers.

comments: author: Barry Hus
body: OK thanks. That is what I suspected.


author: Cory_Schires
body: [@Iain Dooley](/t5/user/viewprofilepage/user-id/1416112) I would like to get a list of all watchers via the API. Is this still unavailable?

Thanks for confirming!


author: Iain Dooley
body: [@Cory_Schires](/t5/user/viewprofilepage/user-id/3661056) what do you need to do with that list though? There may be another way to achieve the outcome you're after.


author: Cory_Schires
body: I would like to create an API integration which...

1. If you're watching a card

2. When the card moves into a specific Trello list (in our case the "Done" list)

3. Then ping / DM the watcher on Slack (i.e. letting them know the card is done)

I have an alternate solution (which will work but I have not yet coded it)...

1. If a member leave a comment of "PINGME"

2. When the card moves into a specific Trello list (in our case the "Done" list)

3. Then ping the watcher on Slack (i.e. letting them know the card is done)

This would work \^ But it's a bit more complicated to code and little less intuitive UX imo. But, whatever, it'd work alright form my use case.

Any suggestions would be appreciated!


author: Iain Dooley
body: [@Cory_Schires](/t5/user/viewprofilepage/user-id/3661056) there's no notification generated when a card is watched/unwatched as far as I can see, but if you register a webhook for a member then you get notified when that member is added to a card, which means you can generate a webhook to watch that card. Then you can ping the person on slack when something happens to that card.


author: Cory_Schires
body: [@Iain Dooley](/t5/user/viewprofilepage/user-id/1416112) Thanks for the tip. Unfortunately, members won't work for my use case. I am already using members to determine / track who is working on the card.

But, as you can imagine, you may want to be notified when a card is completed even if you're not working on it. For example, a member of the sales team may want to be notified when a card is completed (e.g. a bugfix) but they are not actually working on the card so I wouldn't want to add them as a member.

Honestly, it seems like this type of use case is exactly what "Watch" is made for? Is there a reason you cannot expose watchers in the API? While I understand it's not totally essential, it does feel like an omission (i.e. something that really ought to be accessible via the API).

Thanks again for following up!


author: Iain Dooley
body: [@Cory_Schires](/t5/user/viewprofilepage/user-id/3661056) well, yeah when you're watching a card you already get notified when that stuff happens, and registering a webhook against a card is like telling your application to watch the card.

What you need is a way to watch the card by registering a webhook, when the user clicks "watch" which to me doesn't make much sense.

What I think might be a better bet is to go the other way and have the user add a label "Watch" when they want to watch a card, then you can register a webhook against the card and notify the member in their designated slack channel. If you were executing the API as the user you could also watch the card for them, which means they'd receive the notification in both Trello and Slack.


author: Cory_Schires
body: Sorry for so many back-n-forths. I'm afraid I am not being clear.

I already have a webhook setup, meaning my app is notified whenever just about anything happens. I've had that much in place for years.

So here's the process I am trying to accomplish:

1. When a card moves into a new list (in my case, specifically the "Done" list).
2. Then my webhook is triggered. (So far, so good. I already have all this in place.)
3. In my webhook code, I would like to...
   1. Determine which members are watching this card.
   2. DM each of those users on Slack.

And the specific problem / shortcoming in the API is point 3.1. As far as I can tell, there's no way, using the API, to determine which members are watching a given card.


author: Iain Dooley
body: [@Cory_Schires](/t5/user/viewprofilepage/user-id/3661056) that's correct, there's no way to get a list of people watching a card, and no way to receive a notification for a "watched card" event on any model.

You would need some other way of people designating that they want to be notified about that card. Obviously my suggestion of using a label won't work for multiple users, but you can get a list of people who have voted on a card via the API, so you could just repurpose voting as a means of signalling that you want a Slack DM when the card is moved to Done.