Bolt for Python Custom Step Template

This is a Bolt for Python template app used to build custom steps for use in Workflow Builder.

Setup

Before getting started, first make sure you have a development workspace where you have permission to install apps. Please note that the features in this project require that the workspace be part of a Slack paid plan.

Developer Program

Join the Slack Developer Program for exclusive access to sandbox environments for building and testing your apps, tooling, and resources created to help developers build and grow.

Installation

Using Slack CLI

Install the latest version of the Slack CLI for your operating system:

• Slack CLI for macOS & Linux
• Slack CLI for Windows

You'll also need to log in if this is your first time using the Slack CLI.

slack login

Initializing the project

slack create my-bolt-python-custom-step --template slack-samples/bolt-python-custom-step-template
cd my-bolt-python-custom-step

Creating the Slack app

Use the following command to add your new Slack app to your development workspace. Choose a "local" app environment for upcoming development:

slack install

After the Slack app has been created you're all set to start developing!

Using Terminal

Create Your Slack App

1. Open https://api.slack.com/apps/new and choose "From an app manifest"
2. Choose the workspace you want to install the application to
3. Copy the contents of manifest.json into the text box that says *Paste your manifest code here* (within the JSON tab) and click Next
4. Review the configuration and click Create
5. Click Install button and Allow on the screen that follows. You'll then be redirected to the App Settings dashboard.

Environment Variables

Before you can run the app, you'll need to store some environment variables.

1. Open your apps setting page from this list, click OAuth & Permissions in the left hand menu, then copy the Bot User OAuth Token. You will store this in your environment as SLACK_BOT_TOKEN.
2. Click Basic Information from the left hand menu and follow the steps in the App-Level Tokens section to create an app-level token with the connections:write scope. Copy this token. You will store this in your environment as SLACK_APP_TOKEN.

# Replace with your app token and bot token
export SLACK_BOT_TOKEN=<your-bot-token>
export SLACK_APP_TOKEN=<your-app-token>

Initializing the project

git clone https://github.com/slack-samples/bolt-python-custom-step-template.git my-bolt-python-custom-step
cd my-bolt-python-custom-step

Setup your python virtual environment

python3 -m venv .venv
source .venv/bin/activate  # for Windows OS, .\.venv\Scripts\Activate instead should work

Install dependencies

pip3 install -r requirements.txt

Development

Starting the app

Slack CLI

slack run

Terminal

python3 app.py

Linting

# Run ruff from root directory for linting
ruff check

# Run ruff from root directory for code formatting
ruff format

Using Steps in Workflow Builder

With your server running, the Sample step is now ready for use in Workflow Builder! Add it as a custom step in a new or existing workflow, then run the workflow while your app is running.

For more information on creating workflows and adding custom steps, read more here.

Project Structure

app.py

app.py is the entry point for the application and is the file you'll run to start the server. This project aims to keep this file as thin as possible, primarily using it as a way to route inbound requests.

manifest.json

manifest.json is a configuration for Slack apps. With a manifest, you can create an app with a pre-defined configuration, or adjust the configuration of an existing app.

/listeners

Every incoming request is routed to a "listener". Inside this directory, we group each listener based on the Slack Platform feature used, so /listeners/actions.py handles incoming Actions requests, /listeners/functions.py handles Custom Steps and so on.