Dear Celo Community,
Back in January, we published our H1 2026 roadmap and made promises about protocol upgrades, better performance, stronger security, and infrastructure investment. Publishing a roadmap is a little like announcing your New Year’s resolutions to everyone you know: thrilling in the moment, and then suddenly it’s June and people start asking how it’s going.
Good news: it’s going well! Here’s what we actually shipped in H1, and what we’re cooking up for the rest of the year.
H1 2026: What We Actually Did
Jovian Activated
The Jovian hardfork went live on Celo in March. It brought the latest protocol improvements to the network, activated without drama, and continues Celo’s long-term evolution. In blockchain engineering, “nothing exciting happened during the upgrade” is the highest compliment there is.
SP1 Hypercube Upgrade
In May, we upgraded OP Succinct to SP1 Hypercube, a meaningful improvement to proving performance and part of our ongoing investment in scalable, verifiable infrastructure.
And this one comes with numbers worth sharing: proof generation time is expected to drop by more than 75%, and proof generation costs by more than 60%. That means faster, cheaper zk proof generation across the board, and a serious efficiency boost for Celo’s zk fault proof infrastructure. The machinery under the hood is now faster and thriftier.
The Great op-reth Migration Begins
This one wasn’t on the roadmap at all.
When Optimism announced that op-geth was being deprecated, we did what any responsible engineering team does: we recalibrated, reprioritized, and quietly rearranged the whiteboard. Migrating to op-reth (the execution client that will serve as the long-term foundation for the broader ecosystem) quickly became a top priority to keep Celo compatible with future upgrades.
The migration is already complete on Celo Sepolia, and Mainnet is planned for H2 once the ecosystem is ready.
Considerable Progress on Espresso
We also made major headway integrating Espresso into Celo, which is exactly what it sounds like: a shot of speed for the network.
Once complete, Espresso will provide fast confirmations backed by decentralized consensus, all while preserving Celo’s existing architecture and security model. It’s one of the largest protocol initiatives we’ve got going, and the work continues into H2.
What’s Ahead in H2 2026
The second half of the year is about big protocol upgrades, higher throughput, tighter security, better infrastructure, and research that shapes what comes next. As always, sequencing may shift as dependencies get finalized. Consider the timeline confident, not carved in stone.
Protocol Upgrades
op-reth Mainnet Migration
With Celo Sepolia successfully migrated, the main event is next: moving Mainnet from op-geth to op-reth. This puts Celo on the execution client the broader ecosystem is standardizing around, keeps us compatible with future protocol upgrades, and sets the stage for the network improvements ahead.
Espresso Rollout
The caffeine arrives in H2. We expect to launch Espresso on Celo Sepolia during Q3, and pending successful validation, Mainnet deployment should follow shortly after.
What does that mean for you? Dramatically lower confirmation latency. Applications, bridges, exchanges, and everyday users all get a snappier network. Fast confirmations, decentralized consensus, no jitters.
Preparing for Karst
We’re also gearing up for Karst, the next major hardfork. (If you’re keeping track, the upgrade names have now covered a moon of Jupiter, a coffee drink, and a type of limestone terrain. We don’t pick them, but we do enjoy them.)
Karst brings improvements across governance tooling, execution, and protocol capabilities, while continuing Celo’s adoption of the Rust-based Kona fault proving stack. More details and timing to come as planning firms up.z`
Research & Innovation
On the ambitious end, we’re exploring some genuinely high-risk, high-reward ideas: expanding CELO’s role beyond just being the chain’s gas currency, and radically increasing Celo’s decentralization to levels competitive with Ethereum itself.
On the steadier end, we’re also working on lower-risk improvements to scalability and throughput.
Together, this work helps us identify opportunities to strengthen the network while supporting Celo’s long-term vision. Much of it is still in the “heated-but-friendly debates” phase, but we expect some of these efforts to mature into concrete proposals later this year.
Security & Reliability
Security isn’t a feature we bolt on at the end. It’s the foundation everything else stands on. Throughout H2, we’ll keep investing in:
- Strengthening fault proving infrastructure
- Reducing trust assumptions wherever possible
- Improving Celo’s L2Beat rating even further
- Upgrading the Custom Gas Token feature to the latest version
Less glamorous than a hardfork with a cool name, but arguably more important.
Ecosystem Infrastructure
A protocol is only as good as the tools around it, so we’ll keep investing in the day-to-day infrastructure that developers, node operators, and users rely on:
- Continued maintenance and improvements to Valora
- Running the L2 sequencer, batcher, and proposer nodes
- Running Forno, the free public good node service
- Ongoing support for node operators and infrastructure providers
- Better developer tooling and operational infrastructure
Expected Timeline
Q3
- Complete the op-reth Mainnet migration
- Launch Espresso on Celo Sepolia
- Continue research and innovation initiatives
- Continue ecosystem infrastructure investments
Q4
- Prepare for and activate the Karst hardfork, pending implementation readiness
- Continue security and reliability improvements
- Advance research initiatives toward future protocol enhancements
- Continue ecosystem infrastructure and developer tooling improvements
The Road Ahead
H2 is about laying the foundation for Celo’s next chapter: major upgrades, faster confirmations, ongoing research, and steady ecosystem investment, all aimed at a network that’s faster, more resilient, and built for the long haul.
As always, we build in the open. We’ll keep sharing updates as milestones land, and we’re looking forward to doing this alongside all of you for the rest of the year.
See you at the next hardfork.
The Engineering Team-Celo Core Co.