Slack Agent

A Mastra template for building Slack bots powered by AI agents with streaming responses and thread-based conversation memory. Each agent gets its own Slack app and webhook route. Built with Mastra.

Why we built this

Connecting AI agents to Slack is one of the most common integration patterns — whether for internal tools, customer support, or team automation. This template shows how to wire up Mastra agents to Slack with proper streaming, thread memory, and multi-agent support. It includes two demo agents (reverse, caps) to demonstrate the pattern, so you can swap in your own agents and be up and running quickly.

Prerequisites

• OpenAI API key: Used by default, but you can swap in any model
• Slack app with bot token and signing secret (one per agent)
• ngrok or similar tunnel for local development

Quickstart 🚀

1. Clone the template
   • Run npx create-mastra@latest --template slack-agent to scaffold the project locally.
2. Add your API keys
   • Copy .env.example to .env and fill in your OpenAI API key and Slack credentials.
3. Create Slack apps
   • For each agent, create a Slack app at api.slack.com/apps → Create New App → From scratch.
   • OAuth & Permissions → add scopes: app_mentions:read, channels:history, chat:write, im:history. Copy the Bot User OAuth Token to .env.
   • Event Subscriptions → enable and set the Request URL to https://your-server.com/slack/{agentName}/events.
   • Subscribe to bot events: app_mention, message.im.
   • Agents & AI Apps → toggle on.
   • Basic Information → copy Signing Secret to .env.
4. Start the dev server
   • Run ngrok http 4111 to get a public URL, then npm run dev and open localhost:4111 to try it out.

Making it yours

This template is a starting point. Here are some ideas to make it your own:

• Swap in your own agents — replace the demo agents with agents that do something useful for your team. Add a Slack app config in src/mastra/slack/routes.ts and the corresponding env vars.
• Add tools and workflows — give agents access to APIs, databases, or multi-step workflows that execute when triggered from Slack.
• Customize streaming behavior — adjust the spinner animations, status messages, and typing indicators in src/mastra/slack/streaming.ts.
• Deploy to production — remove ngrok and deploy behind a public URL with proper TLS.

About Mastra templates

Mastra templates are ready-to-use projects that show off what you can build — clone one, poke around, and make it yours. They live in the Mastra monorepo and are automatically synced to standalone repositories for easier cloning.

Want to contribute? See CONTRIBUTING.md.