Build an AI Slack Bot with Google Gemini in n8n (Webhook)

Build an AI-powered Slack bot with Google Gemini in n8n—using a Webhook + Slash Command

This n8n workflow example shows you how to create a Slack bot that receives messages from a Slack slash command, sends the content to an AI Agent powered by Google Gemini, and then posts the processed result back to Slack.

What this workflow does

• Create a copy of the workflow in n8n to get started quickly.
• Create a Slack bot in your Slack workspace.
• Add a Slack slash command (e.g., /Bob) and paste your workflow’s webhook URL into the command.
• Send incoming data to the webhook, then pass that data to an n8n AI Agent for processing based on the queries you configure for the agent.
• Enable memory from Slack context by setting the slack token to the memory node—so the agent can reference prior chat history.
• Return a Slack message with the processed output. Because Slack responses must be handled within about 3000 ms, the workflow creates a new message that references the original input.

Use cases

• Answer questions in Slack using Gemini, triggered instantly via a slash command.
• Summarize or rewrite messages while keeping context from previous chats (via memory tied to Slack history).
• Prototype AI features for your SaaS team—start with a webhook endpoint, then customize the agent’s instructions and outputs.

Technical details

• Slack integration (slash command + posting results)
• Webhook trigger for receiving Slack requests
• Google Gemini via n8nn8n-nodes-langchainlm chat google gemini
• AI Agent using n8nn8n-nodes-langchainagent
• Memory using n8nn8n-nodes-langchainmemory buffer window
• Includes supporting nodes such as Sticky Note for workflow clarity

Important: Configure the webhook using a https:// wrapper. Don’t rely on the default http://localhost:5678, since Slack won’t recognize it.