n8n - 💡(How to fix) Fix Slack node V2 demands deprecated chat:write:bot scope, blocking bot-token credentials [3 comments, 3 participants]

Summary

The Slack V2 node hardcodes a check for the deprecated chat:write:bot OAuth scope in packages/nodes-base/nodes/Slack/V2/GenericFunctions.ts:99. Slack removed chat:write:bot and replaced it with chat:write in 2020 (Slack scope migration docs) — chat:write:bot is no longer selectable in the Slack app dashboard. The node therefore rejects every modern bot-token credential with a misleading error.

Reproduction

1. Create a Slack app, give the bot user the modern chat:write scope (the only chat:write:* scope Slack still offers besides chat:write.customize and chat:write.public).
2. Install the app to a workspace, copy the Bot User OAuth Token (xoxb-...).
3. In n8n, create a Slack API credential and paste the token.
4. Add a Slack node with Resource: Channel, Operation: Send a Message, target a channel the bot is invited to.
5. Execute.

Expected: message posts to channel.

Actual: node fails with:

Your Slack credential is missing required Oauth Scopes Add the following scope(s) to your Slack App: chat:write:bot

That scope can never be added — the Slack OAuth dashboard does not list it. Adding chat:write (the modern equivalent that the bot already has) does not satisfy n8n's check.

Stack trace

``` NodeOperationError: Your Slack credential is missing required Oauth Scopes at ExecuteContext.slackApiRequest (.../n8n-nodes-base/nodes/Slack/V2/GenericFunctions.ts:99:10) at ExecuteContext.execute (.../n8n-nodes-base/nodes/Slack/V2/SlackV2.node.ts:890:23) ```

Environment

• n8n version: 2.19.1 (self-hosted, Docker, n8nio/n8n:2.19.1)
• Slack node version: 2.4 (Latest)
• Date encountered: 2026-05-05

Why this is not fixed in 2.19.2 or 2.20.0

I verified by SHA: packages/nodes-base/nodes/Slack/V2/GenericFunctions.ts is byte-identical between tags [email protected] and [email protected]. The 2.20.0 Slack-related change (#28728) is for OAuth2 user_scope customization, a different concern.

``` $ curl -s 'https://api.github.com/repos/n8n-io/n8n/contents/packages/nodes-base/nodes/Slack/V2/[email protected]' | jq -r .sha cb8f33b793b16f5e31685a520dd9c1b297da2ae4

$ curl -s 'https://api.github.com/repos/n8n-io/n8n/contents/packages/nodes-base/nodes/Slack/V2/[email protected]' | jq -r .sha cb8f33b793b16f5e31685a520dd9c1b297da2ae4 ```

Proposed fix

In Slack/V2/GenericFunctions.ts, replace the literal chat:write:bot in the required-scopes set with chat:write. The legacy bot-only scope variant has been gone from Slack for years; any lingering references are stale.

Workaround for affected users

Use the HTTP Request node with an incoming webhook URL instead of the native Slack node. The webhook API is unaffected by the scope check because n8n never inspects the credential.