Boltz.exchange, a popular bitcoin swap service, has suspended its operations indefinitely after facing a series of AI-assisted cyber attacks. The company said the attacks became too difficult for its small team to handle because attackers were finding and testing new methods faster than the team could fix security problems.

Boltz announced the suspension on August 3, saying it could not safely continue operating while its infrastructure remained under attack. The company said it had experienced several attacks over the past few months, but each one had been contained.

"Over the past months we have seen a steady rise in automated, AI-assisted probing of our infrastructure, and we have dealt with several exploits," Boltz said. "Each was contained, but the pattern is clear: attackers now iterate faster than a team our size can find and patch."

Boltz connects different parts of the Bitcoin ecosystem, allowing users to swap bitcoin between the main Bitcoin network, the Lightning Network and the Liquid network. The service is non-custodial, meaning users keep control of their funds throughout the swap process.

The service first went offline early on August 3 without explanation. Several hours later, the company confirmed that the shutdown would continue "until further notice" as it reviews its security and responds to the attacks.

The company said that no user funds were lost during the attacks. Instead, Boltz itself covered the financial losses caused by the security incidents. The team explained that its system was designed so that users' bitcoin never comes under the company's direct control.

"To be explicit: no user funds were ever at risk. Boltz is non-custodial by design. And as a fully bootstrapped company, the losses were ours alone," the company said.

Although swaps have been stopped, Boltz said some services remain available. Its refund API continues to help users complete refunds for unfinished swaps, and customers can also use unilateral refund options without depending on Boltz's systems.

The suspension followed an earlier problem on August 1, when Boltz disabled some swaps involving EVM-based assets, including USDT, USDC, WBTC, TBTC and RBTC. The company said the earlier issue was caused by a bug in its EVM integration. At that time, Bitcoin, Lightning and Liquid swaps were still working.

Two days later, Boltz stopped all swap services after concluding that it could not safely restart operations while facing ongoing attacks. The company said it had detected activity from what it described as "multiple resourceful groups."

Boltz did not identify the attackers or provide detailed technical information about the attacks. The company said it is still reviewing security findings and will provide more information after completing its investigation.

The shutdown has affected several Bitcoin wallets and services that depended on Boltz for swap functions. Bull Bitcoin, a Bitcoin-focused wallet service, said Lightning payments and Liquid-to-Bitcoin conversions were temporarily affected.

Francis Pouliot, CEO of Bull Bitcoin, said his company was working quickly to restore the affected features. "I will not let this situation linger. I will fix it, no matter what it takes," he wrote.

Aqua wallet, which uses Boltz infrastructure for some swap features, was also affected. Samson Mow, CEO of JAN3, the company behind Aqua, said restoring Lightning and Liquid swap functions was the team's top priority. He added that Aqua had offered to help Boltz improve its security.

Lightning wallet ZEUS also disabled its own Boltz-based swap service. The company said it was taking the same approach as Boltz while the security situation was being reviewed.

The incident has raised concerns about the security challenges facing smaller open-source projects. Open-source software allows developers and researchers to examine code publicly, but it can also give attackers more opportunities to search for weaknesses.

Boltz described the situation as a "major paradigm shift" for Bitcoin services built on open-source software, warning users not to expect swap services to return anytime soon.