Slack

Slack provides a web application programming interface (API) for programmatically interacting with its messaging service.

The Slack API is an implementation of the web application programming interfaces concept. Learn how these pieces fit together in the web development chapter or view the table of contents for all topics.

Slack resources

How to Build Your First Slack Bot with Python contains all the code for getting a Slack bot up and running with Python even if you have not previously worked with their API or built other bots.
Use a Slack bot to deploy your app gives the sample code to a simplified bot that you can engage with in your chat channels to perform application deployments.
How I built a Slack bot to help me find an apartment in San Francisco is a story about how the author had issues finding an apartment while moving from Boston to San Francisco. He started scraping Craigslist to gather apartment data and built a Slack bot to message him as soon as something that matched his criteria became available so he could take a look at it.
Slack on an SNES is not a Python tutorial but it provides a crazy hack for communicating with Slack using a Super Nintendo.
Hacking Slack accounts: As easy as searching GitHub explains how secret Slack API keys are often committed to public GitHub repositories which allows malicious actors to easily break into an organization's messaging systems. Secret credentials in public repositories is a problem for any API and it is a particular problem for ones that are critical to a business' private communications.
Serverless Slash Commands with Python shows how to build a serverless Flask plus Zappa framework web app that is hosted on AWS Lambda and can use the Slack API.
Hacking Slack using postMessage and WebSocket-reconnect to steal your precious token examines a bug that the author found in Slack's WebSockets reconnection operation that he reported to Slack. Slack fixed the issue and paid him a bug bounty for his work.
Posting messages to Slack using incoming webhooks and Python3 Requests API is a short script that uses the Requests library instead of the Slack-provided Python helper libraries to interact with the API.
Build a Google Analytics Slack Bot with Python walks through creating a bot that posts Google Analytics data into Slack channels by combining the Slack and Google APIs.

Example Slack bots

python-rtmbot is the Slack-provided library for working with the Slack API and WebSockets connection.
slackify is a lightweight framework for building bots and the quickstart walks you through how to create a simple example bot.
slack-starterbot
slack-api-python-examples contains the example code from several Slack bot blog posts.
slackbot another popular Slack bot implementation.