Is there a way to build a script / bot (using any language) that can read messages from a slack channel on which I am a user, however I do not have admin access? I’m a user but don’t own the workspace so I can’t add bot integrations or use the API. Maybe I can use selenium or an AppleScript?
The only way to accomplish this is with the Slack API and the [conversations.history][1] endpoint. You can use that endpoint with either the user token or the bot token. But to use the Slack API you have to create and install an app, there's no way around that. Sounds like your Workspace might have Admin Approved Apps enabled which will require your admin to review and approve your app prior to installation.