To use Claude in Slack, you will first need to install the Claude App for Slack. Note that the Claude App for Slack is only available in Enterprise Grid.
To install Claude, visit the Claude App for Slack and click "Add to Slack". This will prompt you to select the workspace on which you want to install Claude. Click "Authorize".
After the install, Claude will appear as a bot user in your Slack workspace. Users can then interact with Claude by:
Direct messaging @Claude: this will open a DM channel between the user and Claude where you can chat.
Mentioning @Claude in any public channel: Claude will respond to commands and questions in the channel.
Using slash commands like /claude help: this will trigger Claude to respond with information on how to use his capabilities.
Once installed, all members of that Slack workspace will have access to use Claude. The installation only needs to be done once per workspace.