what's Prysm?
Prysm is an open-source Ethereum consensus client designed to implement the proof-of-stake protocol for Ethereum 2.0. Developed initially by Prysmatic Labs and now maintained by Offchain Labs, it enables users to run beacon nodes and validator clients that participate in Ethereum's consensus mechanism. Prysm supports key Ethereum upgrades by handling beacon chain operations, fork choice rules, and attestation processes, ensuring secure and efficient network validation. The client is built in Go and emphasizes modularity, allowing integration with execution clients like Geth for full node operation. It includes features for depositing ETH into the beacon chain, syncing with the network, and optimizing resource usage during high-load scenarios. Prysm's development focuses on stability, peer discovery, and compatibility with Ethereum's evolving specifications, contributing to the decentralized infrastructure of the Ethereum ecosystem.
Prysm now supports Post Quantum consensus devnets as an established client with Lighthouse and Grandine.
Links
x.com/prylabsPrysm team member is presenting at ETHDenver about EIP-7732, described as one of the most essential upgrades coming to Ethereum.
Featured at ETHDenver 2026 through a speaking session by Terence Chain, an Ethereum core developer at Offchain Labs who implemented Prysm.
Added support for Post Quantum consensus devnets as an established consensus client alongside Lighthouse and Grandine.
Struggles to sync from an out of sync state, with a fix planned in another release before the end of 2025.
Lighthouse client has caused DOS (Denial of Service) to Prysm twice, raising concerns about ePBS implementation when lagging nodes can accidentally DOS non-lagging nodes.
Ethereum co-founder Vitalik Buterin addresses the Prysm client bug, saying there is nothing wrong with Ethereum temporarily losing finality on occasion provided incorrect blocks are not finalized.
Version 7.1.0 releases with two new features: checkpoint sync backfilling of data columns for Fulu (enabled with --enable-backfill flag) and semi-supernode mode that allows nodes to custody enough data columns to rebuild blobs without full supernode setup.
Version 7.0.1 releases with a permanent fix for the mainnet attestation processing issue from Dec 4 and deprecates the --disable-last-epoch-targets workaround flag, with operators encouraged to update immediately.
Network recovers to 99% voting participation after Prysm bug brought Ethereum within 9% of losing finality at 75% participation. Prysm validator market share drops from 22.71% to 18% post-incident.
Statediff support rolls out in next few releases to permanently fix the historical state reconstruction vulnerability that caused DOS-like conditions. The Prysm bug shifts client dominance to Lighthouse and temporarily pushes Ethereum to $3.2B ARR for one block during the Fusaka upgrade.
The ongoing Prysm issue is resolved with a workaround flag '--disable-last-epoch-targets' for v7.0.0 after the bug caused ~23% of the Ethereum network to drop off and miss slots.
An ongoing issue affects Prysm nodes, with investigation currently underway and updates pending.
6-second slots are fully spec'd, prototyped in Geth and Prysm, and ready to ship next year in the Heka/Bogotá fork, with a first local devnet now running.
A Fusaka livestream takes place on December 3 featuring speakers from Prylabs alongside Nethermind, Ethereum Foundation, Go Ethereum, Erigon, Taiko, and Offchain Labs to educate node operators, L2 teams, and developers about the upgrade.
Version 7.0.0 launches as a mandatory update before epoch 411392 for the Ethereum Fulu fork on December 3, 2025, with key changes including by-epoch blob storage, removed deprecated APIs, and increased builder gas limits.
Version 6.1.4 releases with bug fixes for rare block proposal issues and Windows compatibility updates for post-Fusaka fork, with immediate upgrade recommended for optimal validator performance.
Performance Engineering team at Ethereum Foundation reduces attestation propagation latency in Prysm by 6x, enabling potential implementation of 6-second slots versus current 12-second slots and other L1 scaling proposals.
Version 6.1.3 releases with beacon API and p2p fixes, correcting gossip attestation rejection issues when attestations arrive before referenced blocks.
Arbitrum through Offchain Labs owns Prysmatic Labs through an acquisition/partnership arrangement.
Major Ethereum upgrade Pectra is live on mainnet with significant contributions from development team.
Critical protocol upgrade v6.0.0 released with May 7, 2025 deadline for all node operators and validators.