This repo contains a sample app for doing OAuth with Slack. It uses the python-slackclient and python-slack-events-api. It has been tested on python 3.7.5.

I recommend using ngrok for local development of slack apps. Checkout this guide for setting it up.

pip3 install slackclient
pip3 install slackeventsapi
pip3 install flask

This app requires you setup a few enviroment variables. You can get these values by navigating to your app's BASIC INFORMATION Page.

export SLACK_CLIENT_ID = YOUR_SLACK_CLIENT_ID
export SLACK_CLIENT_SECRET = YOUR_SLACK_CLIENT_SECRET
export SLACK_SIGNING_SECRET = YOUR_SLACK_SIGNING_SECRET

You also need to setup FLASK_APP enviroment variable so flask run knows what to run. This should point to this repos app.py.

export FLASK_APP=app.py

Start the app by running the following command

flask run

This will start the app on port 5000.

Now lets start ngrok so we can access the app on an external network and create a redirect url for OAuth and a request url for events.

ngrok http 5000

This should output a forwarding address for http and https. Take note of the https one. It should look something like the following:

Forwarding   https://3cb89939.ngrok.io -> http://localhost:5000

Go to your app on https://api.slack.com/apps and navigate to your apps OAuth & Permissions page. Under Redirect URLs, add your ngrok forwarding address with the /finish_auth path appended. ex:

https://3cb89939.ngrok.io/finish_auth

Now go to Event Subscriptions and enable events. For the Request URL, pass your ngrok forwarding address with /slack/events path appended. ex:

https://3cb89939.ngrok.io/slack/events

While you are in Event Subscriptions, add the member_joined_channel event as the app uses it to send a direct message.

Everything is setup. Go to http:localhost:5000/begin_auth in your browser to start the OAuth install flow for you app!