Open-model AI company Fireworks has contracted capacity from UK-based data center provider Era4.

Under the agreement, Fireworks will lease 5MW of direct-liquid-cooled capacity powered by Nvidia Blackwell Ultra HGX B300 GPUs at Era4’s data center in Chesterfield, Derbyshire.

Through this, Fireworks’ model training and inference platform will be combined with infrastructure owned and operated in the UK, and will initially target financial services, insurance, and life sciences sectors.

“Companies want AI they can specialize to their own data and the way they work,” said Lin Qiao, co-founder and CEO of Fireworks. “They also want a choice about where those models run. This agreement with Era4 expands our capacity in the UK for developing new services for banks, fintechs, UK enterprises, and other regulated businesses.”

Fireworks has existing deployments in Germany and Iceland.

“Europe has the talent, the data and the demand to lead in enterprise AI, but it cannot lead on compute it does not control. For a bank or insurer, knowing where its AI runs is part of the buying decision,” added Tom Humphreys, CEO of Era4. “At Chesterfield, we own and operate the infrastructure, including behind-the-meter power generation. Working with Fireworks lets us build on that foundation with tools enterprises can use to adapt and run open models.”

Era4’s Chesterfield site offers the HPE ProLiant Compute XD685 servers in an HPE AI Mod POD modular data center. The site is primarily powered by landfill gas captured at the site and uses grid connection for backup power.

Launched last year as Carbon3.ai, Era4 rebranded earlier this year. The company revealed details of its AI platform in September 2025, claiming at the time that it would eventually comprise 100,000 GPUs, aiming to reach more than 30 locations.

Plans for the modular AI data center in Derbyshire were unveiled in November 2025, and in December it said it had signed an agreement to deploy Nvidia Blackwell Ultra AI infrastructure with HPE’s direct liquid-cooled servers.

Elsewhere, the company saw a proposal for a site in Anglesey rejected, but proposed another site in Canterbury, Kent, which will be powered by landfill gas. The firm has also teamed up with another UK company, Civo, to launch a sovereign AI cloud.

In late October, Era4 revealed it was targeting a 1GW AI campus in Newport, Wales, which would be by far its biggest site.