Developing locally using the Slack CLI

The Slack CLI provides some features, and customization of said features, to streamline developing apps locally. This guide details those features.

Configuring file watching and auto-restart

The Slack CLI automatically watches your app files and restarts the server when they change. It also watches manifest.json and reinstalls the app when the manifest changes.

For Bolt for Python projects, the Slack CLI watches all .py files in the root directory (See python-slack-hooks/get_hooks.py).

For Bolt for JavaScript projects, the Slack CLI watches all .js files in the root directory (See @slack/cli-hooks).

View the hooks reference for detailed configuration options.

Customizing watch paths

You can override the default watch paths in .slack/hooks.json if so desired.

For example, if you're building an agent you'll likely want to include your system prompt and tool definitions:

{
  "config": {
    "watch": {
      "manifest": {
        "paths": ["manifest.json"]
      },
      "app": {
        "paths": ["app.js", "system-prompt.md", "tools/"],
        "filter-regex": "\\.(ts|js|md)$"
      }
    }
  }
}

This Bolt for JS example watches the following files and paths, while filtering out any files that aren't .ts, .js, and .md files within those paths:

• app.js, which is your main app file,
• system-prompt.md, which is your agent's system prompt, and
• tools/, which is your tool definition directory.

A restart clears application state. This is usually desired! For example, when you update your agent's system prompt, you don't want it to remember the old behavior. Just be aware of this if you're testing workflows that require data to persist across multiple user interactions.

Using a remote manifest

By default, the Slack CLI uses your local manifest and reinstalls the app if it changes. If you've created your manifest in App Settings, however, you'll have manifest.source set to remote in .slack/config.json and will need to manually reinstall the app if you change the manifest.