What time is it? It’s time to build.

Introducing </time2build>: a one-of-a-kind worldwide developer challenge to bring bitcoin into the open-source apps that we use every day.

Kicking off on October 7th, developers around the globe have the opportunity to display their skill and creativity by adding bitcoin to open-source apps using the Breez SDK. From November 16th, participants have a month to work with project maintainers to merge their code, making sure what they build actually ships. Successful projects will have the chance to share in the $25,000 prize pool, with winners announced on January 8th, 2026.

</time2build> isn’t another hackathon or bounty. Hackathons end. Bounties disappear. The ambitious challenge is about planting open-source seeds in the soil of the applications that shape our lives. With open-source projects, we’re not just tweaking apps, we’re building a monetary layer that’s as open, global, and unstoppable as the internet itself.

Builders have long recognized Bitcoin’s potential, but they lacked the tools. With Lightning, we have a common language to connect the formidable Bitcoin superhighway to the various last-mile technologies that amplify its utility, like Spark and Liquid. There’s no excuse anymore. The time to build is now.

And the timing couldn’t be better. As cash disappears, so do its benefits: instant settlement, peer-to-peer transfer, and permissionlessness. For years, Bitcoin promised to bring those virtues to the digital world, and now all the tools are finally in place to make freedom user-friendly. So stop asking if you can build with Bitcoin and start imagining what you will.

Open-source software already powers the internet and the tools we trust. Bitcoin is no exception. Being open-source is one of the ways Bitcoin maintains its openness, borderlessness, and sheer unstoppability.

By adding open-source value to open-source apps, we’re improving both. Open-source is how we pave the way to a new economy without walled gardens, free trillions in captive value, and make bitcoin as easy and ubiquitous as the Like-button.

</time2build> is about much more than your uncle’s fintech. Think bigger. With the tools at our disposal, every app, every service, and every platform can move value as easily as information. That’s what you’re here to build.

We call on builders everywhere to build messaging apps that let users send sats like DMs, real-time tipping to content creators of all kinds, and social apps that let users raise funds and split bills with the ease of liking a post. You can build an app that responds to use cases we haven’t even imaged yet.

Over 40 developer communities from Nigeria to Mexico, Argentina to Austria, Lugano to London are participating in the challenge. They are united by the same conviction: value should flow as freely as information. Together, they’re proving that bitcoin is no longer just something to hodl. It is something to build on, to build with, and to build for.

We’ve also joined forces with some of the biggest names in Bitcoin: Tether, Lightspark, Plan ₿ Network, and Fulgur Ventures. They are backing the challenge with a $25,000 prize pool, along with special residencies at the Austin accelerator PlebLab and Draper University. Project submissions will be reviewed by a panel of industry leaders and luminaries from around the world.

The era of building starts now. With builders. With open-source. With you.