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Unilateral Exit Is Now Live

Leo & Kevin
Jul 28, 2025
5 min read

If you have to ask anyone besides Bitcoin for your Bitcoin back, it's wrapped. Today, we're introducing unilateral exit to Spark: any user can now withdraw their funds back to Bitcoin without needing permission from anyone, even if Spark shuts down.

Scaling Bitcoin comes with tradeoffs. You have to make tough calls. Chief among them: should the system prioritize UX or absolute trustlessness?

When Kevin (CTO & inventor of Spark) first sketched out Spark, one feature was non-negotiable: unilateral exit. Simply put, unilateral exit lets any user withdraw their Bitcoin back to L1 at any time without needing permission from Spark, an operator, or anyone else. It's straightforward, yet essential: if everything else fails, your Bitcoin stays yours.

Today, unilateral exit is officially live on Spark.

Unilateral Exit is Freedom

Most scaling solutions today never mention “Unilateral Exit” in their docs. It’s an overlooked idea, almost forgotten. 

At Spark, we believe the winning Bitcoin scaling solution is the one that gives users maximum freedom. Bitcoin’s essence is freedom. Once you lose that, you lose Bitcoin itself. Spark is freedom-first.

  • Freedom to leave the network anytime.
  • Freedom from censorship.
  • Freedom to fully control your own Bitcoin.


That freedom begins with unilateral exit. Everyone should be able to reclaim their Bitcoin, even if Spark itself tried to censor them.

Scaling Bitcoin using multisigs or bridges creates choke points. Most of these systems rely on a small group of participants who, even without malicious intent, hold far too much power. Their mere ability to censor or block access opens the door to serious attacks. 

Unilateral exit on Spark is the culmination of everything we’ve learned the hard way. We’ve seen what happens when you compromise on freedom and we’re not making that mistake again.


How does it work in practice?

The quick answer is that when you deposit funds into Spark, you receive a pre-signed exit transaction upfront. Even if the Operator goes offline or tries to censor you, you can independently broadcast this transaction after a timelock and securely reclaim your funds on-chain.


Try it now

You can test unilateral exits yourself today. Just a quick heads-up: unilateral exits can take longer and be more expensive than regular exits. That's by design (safety > UX). Also, if you already have funds on Spark, you'll need to redeposit them to enable this feature, as it’s not backward compatible until now. 

Check our official docs here to learn exactly how to broadcast your unilateral exit transaction.