As Facebook prepares to roll out Instant Articles to all publishers next month, the company said Monday that it’s partnering with WordPress.com’s parent Automattic to release an Instant Article WordPress plugin.

The plugin creates a special RSS feed that automatically optimizes posts to appear as Instant Articles. The plugin is open-source and customizable. Its documentation is available here on Github.

Facebook said it worked with “a small group of publishers” that run on WordPress, including Foreign Policy and Tribune Media’s Zap2it, to test the plugin.

In a blog post, Facebook noted how the plugin formatted this Foreign Policy story for Instant Articles:

For example, the plugin recognizes the image found in this Foreign Policy article and specifies the correct markup so the photo renders properly in the Instant Article. The photo expands to fill the screen when tapped and allows exploration by simply tilting the phone.

The plugin “also supports native autoplay video as well as social and interactive graphic embeds,” Facebook said.

In its own post, Automattic explained that anyone using the Instant Articles plugin will have to undergo review by Facebook to ensure their pages are “properly formatted and adhere to their community standards and content policies before you’ll be able to start pushing content to the platform.”

Instant Articles will be available to anyone starting April 12, when Facebook holds its annual F8 developer conference in San Francisco. Hundreds of publishers are already publishing on Instant Articles.

“It has always been our vision to create something that works for publishers all over the world,” Facebook product manager Josh Roberts told the Lab’s Laura Hazard Owen last month.

Facebook’s move to make it easier for outlets to use Instant Articles comes after Google unveiled its Instant Articles competitor, Accelerated Mobile Pages, in February. AMP is open source, and Richard Gingras, Google’s head of news and social products, told the Lab’s Shan Wang that more than 80 developers had contributed code to AMP’s GitHub repo since AMP was announced last fall.

“I don’t think we could’ve made it this far without the participation and collaboration of so many people,” Gingras said. “When we say ‘we,’ it’s not the Google ‘we’ — it’s the collaborative ‘we’ of hundreds of publishers and tech companies that have engaged with the open-source effort.”

Facebook similarly encouraged developers to contribute to the plugin’s development on Github. It notes that the “plugin is still in early stages and the underlying APIs (like filters, classes, etc.) may change.”

Facebook has continued to tweak Instant Articles as it receives feedback from news organizations already using the product. Facebook now lets publishers solicit email newsletter signups in Instant Articles, and in December the company made it easier for publishers to generate ad revenue from Instant Articles.

“The biggest stumbling block with Instant Articles was that we were making less there than with visits to our own site,” Joe Speiser, co-founder of LittleThings.com, told The Wall Street Journal. “We are now seeing parity with our mobile Web version.”