Making good on Elon Musk’s promise, Twitter open sources its recommendation algorithm

It is officially a “new era of transparency” at Twitter.

For a while now, Twitter CEO Elon Musk has been promising that the company would open source its code. That plan has been delayed many times but, earlier this month, Musk announced that the company would open source its recommendation algorithm on March 31st. The recommendation algorithm is what decides which tweets and accounts you see on the app’s For You timeline.

Well, March 31st is here, and it looks like Elon Musk and Twitter have made good on that promise. Today, the company announced in a blog post that it is making much of its source code, including its recommendation algorithm, available in two new repositories on GitHub. The company says that it has “aimed for the highest possible degree of transparency while excluding any code that would compromise user safety and privacy or the ability to protect our platform from bad actors, including undermining our efforts at combating child sexual exploitation and manipulation.”

Musk took to Twitter to announce the release as well, saying that “many embarrassing issues will be discovered, but we will fix them fast!”

In a separate post from the Engineering team, the company provided a breakdown of its recommendation algorithm, saying that tweets displayed on the For You timeline are chosen from three key areas:

• Fetch the best Tweets from different recommendation sources in a process called candidate sourcing.
• Rank each Tweet using a machine learning model.
• Apply heuristics and filters, such as filtering out Tweets from users you’ve blocked, NSFW content, and Tweets you’ve already seen.

While today’s release does include the code that powers the For You timeline’s highlighted tweets, the company did note that it does not include the algorithm that powers ads on the platform. It says that it plans to release more code over time as long as it “does not present a significant risk to Twitter or people on our platform.”

The release comes a day before the company is scheduled to begin sunsetting its legacy verification on the platform. Once sunset, legacy verified accounts will need to purchase Twitter Blue, the company’s paid verification service.