Following the partnership with the Arbitrum Foundation announced in May 2025, Erigon Technologies is excited to announce the first milestone of Erigon Nitro: a v0.1 alpha client for Arbitrum Sepolia.
Transaction-First Architecture
Erigon 3 is built with a transaction-first architecture, processing the chain at the level of individual transactions rather than whole blocks. This design aligns naturally with Arbitrum's sequencer model, which streams transactions rather than pre-assembled blocks — making Erigon a natural fit for the Arbitrum stack.
Dramatic Storage Reduction
The most impressive result of this work is the storage compression achieved. A prototype Erigon Nitro archive node for Arbitrum Sepolia was reduced from 12 TB to 732 GB — a 94% reduction. Minimal nodes require approximately 208 GB of storage.
This advancement enables rapid node bootstrapping: node operators can bootstrap an Arbitrum Sepolia archive node in hours, depending on network throughput. Recovery from failures no longer requires full resyncs.
Technical Specifications
- State growth estimates: Nitro Sepolia experiences ~700 GB/month growth; Arbitrum One sees ~850 GB/month
- Core features: Built on Erigon's proven data model, staged-sync execution pipeline, and OtterSync snapshot delivery mechanism
Development Roadmap
- Q4 2025: Stable Sepolia RPC and execution client
- Q1 2026: Basic Arbitrum One support
- Q3 2026: Full prover support completion
Get Involved
This v0.1 alpha release invites the community to test on Sepolia. Technical setup instructions are available on HackMD, and feedback is welcome via our Discord.