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

Create a 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>

Local Project

# Clone this project onto your machine
git clone https://github.com/slack-samples/bolt-python-custom-step-template.git

# Change into this project directory
cd bolt-python-custom-step-template

# Setup your python virtual environment
python3 -m venv .venv
source .venv/bin/activate

# Install the dependencies
pip3 install -r requirements.txt

# Start your local server
python3 app.py

Linting

Run flake8 and black for linting and code formatting:

# Run ruff from root directory for linting
ruff check

# Run ruff from root directory for code formatting
ruff format
ruff check --fix

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.