Slack Trigger node fails to pull list of channels / credentials issue

Questions
1

Describe the problem/error/question

I am creating a new workflow with a Slack Trigger node, to trigger on any event (for example, doesn’t matter which trigger I select), then I open the “channel to watch” dropdown, and it won’t load the list of channels (error is “Could not load list / Check credentials”).

I have follow all the relevant instructions, given the respective Slack app I created the correct bot scopes (basically I tried giving all possible read scopes, still not working).

It seems to be the same error as mentioned in this Github ticket: Slack Trigger | Channels could not be find · Issue #14124 · n8n-io/n8n · GitHub

What is the error message (if any)?

Screenshot 2025-05-20 at 09.10.49
Screenshot 2025-05-20 at 09.10.49671×985 35.5 KB

Please share your workflow

Share the output returned by the last node

N/A

Information on your n8n setup

  • n8n version: 1.81.4
  • Database (default: SQLite): SQLite
  • n8n EXECUTIONS_PROCESS setting (default: own, main): default
  • Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
  • Operating system: n/a
2 Likes
2

Hi @Nino_Ulsamer

You need to add a scope to your slack app. add channels:read and groups.read.

If this helps solve your issue, make sure to mark it as the solution so others can benifit.

Best,

Robert Breen

3

Hi Robert,

Yes, of course. As mentioned, I added the relevant scopes you flagged (and many more). Also reinstalled the Slack app multiple times after that. Still not working.

Thanks!

1 Like
4

@Nino_Ulsamer
Missed that in your post.

Does it work if you manually type the name? like #channelname

5

actually I am unable to type in the textfield, as while it’s still loading, once I click into the text field, the box closes. and once it’s done loading and errors out, I also cannot use the textfield any longer.

6

I just saw that the call to https://stashaway.app.n8n.cloud/rest/dynamic-node-parameters/resource-locator-results returns with status code 500 and the following response:

  "code": 0,
  "message": "The service is receiving too many requests from you",
  "level": "warning",
  "tags": {},
  "context": {},
  "functionality": "regular",
  "name": "NodeApiError",
  "timestamp": 1747750381370,
  "node": {
    "parameters": {
      "authentication": "accessToken",
      "notice": "",
      "trigger": [
        "any_event"
      ],
      "watchWorkspace": false,
      "channelId": {
        "__rl": true,
        "mode": "list",
        "value": ""
      },
      "downloadFiles": false,
      "options": {}
    },
    "id": "uuid-1234",
    "name": "Temp-Node",
    "type": "n8n-nodes-base.slackTrigger",
    "typeVersion": 1,
    "position": [
      0,
      0
    ],
    "credentials": {
      "slackApi": {
        "id": "...",
        "name": "..."
      }
    }
  },
  "messages": [
    "429 - {\"ok\":false,\"error\":\"ratelimited\"}"
  ],
  "httpCode": "429",
  "description": "ratelimited"
}

not sure if this is on the n8n side, or the Slack side?

1 Like
7

actually I debugged this further, and calling the Slack API directly with the same bot-token, endpoint https://slack.com/api/conversations.list works.

I am assuming that maybe the endpoint on n8n side performs a call to the Slack API for each channel (possibly to load some metadata?) that then results in this getting rate-limited due to the large number of channels (965) that we have?

1 Like
8

@Nino_Ulsamer
That could be. I would wait some time then try again since its hiting a rate limit.

change it to by url so its not checking for channels. Heres an image for how to do that.

image
image833×698 30.8 KB

9

Hi @rbeer I tried both by channel and by ID - they are both not working. There is no more error, but when I test the workflow step and trigger events (messages, reactions, etc) inside that channel, they do not get picked up by n8n.

Also, just to be clear on the rate-limiting: we have no other workflows running that hit the Slack API. And I am making only a single call (=attempting to open the Slack channel search list) which already fails. I have tried waiting for several minutes before trying again. And even if while this query is running I hit the conversations.list endpoint with the same bot-token manually, it’s still working. So something else must be going on within the endpoint that fetches from Slack.

Are there any sorts of logs available to look at?

1 Like
10

@Nino_Ulsamer

I dont know of any logs that you can look at. Guessing the channel search was causing the issue. Not sure of any other solutions.

Best,

Robert

11

ok. I find it a bit shocking that such a basic thing as the Slack integration isn’t working for a paid subscription of the product…

2 Likes
12

@Nino_Ulsamer

The slack integration is certainly something that n8n can do. The problem you are facing is specific to your issue. Its just hard to solve without access to your systems. Sorry I cant be of more help.

13

same problem here. don’t know how to solve, i tried everything about scopes, find by id and url. We have a lot of channels too and it’s shocking that the integration doesn’t work (and that we need an slack app for each trigger). My solution until now is to watch the whole space and insert branchs with paths that direct to others workflows depending on the attributes.