I am using Slack Incoming Webhooks requests to post messages to a Slack channel from an app. I love it since I can send messages directly from shell scripts. However going further I stumble into the problem that I seem to be unable to delete messages. The app has two access tokens: An OAuth access token xoxp-012345678901-012345678901-012345678901-0123456789abcdef0123456789abcdef (this is a fictitious token but the length is the same as the actual token). Bot User OAuth access token xoxb-012345678901-012345678901-0123456789abcdef01234567. Using the xoxp- OAuth access token I can retrieve channel history. curl "https://slack.com/api/channels.history?token=xoxp-012345678901-012345678901-012345678901-0123456789abcdef0123456789abcdef&channel=CABCDABCD&count=20&pretty=1" With the xoxb- token the channels.history request fails with { "ok": false, "error": "not_in_channel" } In chat history I have a message that I would like to delete. The message was posted using Incoming Webhooks associated with the App. { "type": "message", "subtype": "bot_message", "text": ":heavy_check_mark:", "ts": "1580968882.000800", "bot_id": "BABCDABCD", "blocks": [ { "type": "section", "block_id": "5Ov", "text": { "type": "mrkdwn", "text": "text of the message to delete", "verbatim": false } } ] } However neither token works with chat.delete. Both curl "https://slack.com/api/chat.delete?token=xoxb-012345678901-012345678901-0123456789abcdef01234567&channel=CABCDABCD&ts=1580968882.000800&pretty=1" and curl "https://slack.com/api/chat.delete?token=xoxp-012345678901-012345678901-012345678901-0123456789abcdef0123456789abcdef&channel=CABCDABCD&ts=1580968882.000800&pretty=1" fail with { "ok": false, "error": "cant_delete_message" } And the question is: Is there a way to delete a message posted by an app via Incoming Webhooks requests? PS. Both chat:write:bot and chat:write:user permissions are granted.