Slack Python OAuth Example

This repo contains a sample app for doing OAuth with Slack. It uses the python-slackclient and python-slack-events-api packages. 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.

Checkout the full tutorial at https://api.slack.com/tutorials/understanding-oauth-scopes-bot

Before we get started, make sure you have a development workspace where you have permissions to install apps. If you don’t have one setup, go ahead and create one. You also need to create a new app if you haven’t already.

Install dependencies

TODO: recommend using a virtualenv with a link to some instructions. include a requirements.txt with the dependencies.

pip3 install -r requirements.txt

Setup environment variables

This app requires you setup a few environment 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 environment variable so flask run knows what to run. This should point to this repos app.py.

export FLASK_APP=app.py

Run the App

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!