BYOA (Bring Your Own Agent) to Slack.

It should only take 5-10 minutes to get your agent responding to DMs and @mentions in Slack.

1. Go to api.slack.com/apps to create a Slack app -- choose "From scratch"
2. Under OAuth & Permissions > Scopes > Bot Token Scopes, add the following:
   • app_mentions:read
   • assistant:write
   • channels:history
   • chat:write
   • im:history
   • im:write
3. Under App Home > Show Tabs > Chat Tab, check "Allow users to send Slash commands and messages from the chat tab"
4. Under OAuth & Permissions > OAuth Tokens, install the app to your workspace
5. Remix this val if you haven't already
6. Add your environment variables in your val sidebar:
   1. TOWNIE_TOKEN from Settings > API tokens
   2. SLACK_BOT_TOKEN in your Slack app: OAuth & Permissions > OAuth Tokens > Bot User OAuth Token
   3. SLACK_SIGNING_SECRET in your Slack app: Basic Information > Signing Secret
   4. ANTHROPIC_API_KEY from the Claude console
7. Copy your HTTP url in events.ts (note: you can add a custom subdomain), then in your Slack app paste it under Event Subscriptions > Request URL
8. In your Slack app under Events Subscription > Enable Events > Subscribe to bot events, add app_mention, assistant_thread_started, and message.im

townie/
├── events.ts         # HTTP entry point (Hono app, Slack event router)
├── prompt.md         # System prompt for your agent
├── README.md
└── lib/
    ├── generate-response.ts         # AI core (Claude + MCP + web search)
    ├── handle-app-mention.ts        # Handles @mentions in channels and threads
    ├── handle-message.ts            # Handles DMs in assistant (Slack app) threads
    ├── handle-thread-started.ts     # Greeting + suggested prompts on new assistant thread
    └── slack-utils.ts               # Slack client and utils

This template uses Claude Sonnet 4.6 directly in lib/generate-response.ts, which requires setting an ANTHROPIC_API_KEY environment variable. Alternatively, you could use a gateway to switch between models easily, like the Vercel AI Gateway or the Kilo Gateway.

This agent comes with the following tools:

1. Anthropic web search
2. Val Town MCP server

You should of course edit and add your own tools! That's the whole point of BYOA :)

This val uses pinned imports (latest package version as of 2/19/26) to avoid breaking changes:

1. @slack/web-api@7.14.1
2. hono@4.12.0
3. ai@6.0.92
4. @ai-sdk/anthropic@3.0.45
5. @ai-sdk/mcp@1.0.21

This val is based on Vercel's Slackbot Agent Guide, adapted for Val Town.