{"id":751,"slug":"how-are-blockchain-mainnet-upgrades-hard-forks-rolled-out","question":"How are blockchain mainnet upgrades (hard forks) rolled out?","intent":"informational","language":"en","url":"https://worldwiki.io/q/how-are-blockchain-mainnet-upgrades-hard-forks-rolled-out","entity":{"slug":"blockchain-mainnet-development","name":"Blockchain Mainnet Development","url":"https://worldwiki.io/entity/blockchain-mainnet-development"},"answer":{"short_answer":"Proposed rule changes are written up as specifications, such as Ethereum Improvement Proposals, and implemented in every client. They are tested on public testnets, then activated at an agreed block or epoch so that all nodes switch together. On Ethereum, Pectra was rehearsed on testnets and activated on mainnet on 7 May 2025 at block 22,431,084. Fusaka followed on 3 December 2025.","detailed_answer":"<p>Testnet problems during Pectra led to the launch of a new testnet, Hoodi, in March 2025 <span class=\"ref\">[11]</span>.</p>","format":"paragraph","confidence":75,"verified_at":"2026-09-18 07:10:23","updated_at":"2026-09-18 16:10:23"},"sources":[{"id":172,"title":"Networks","url":"https://ethereum.org/developers/docs/networks/","publisher":"ethereum.org","type":"official","accessed_at":"2026-09-18 18:01:28"},{"id":153,"title":"IR 8202, Blockchain Technology Overview","url":"https://csrc.nist.gov/pubs/ir/8202/final","publisher":"National Institute of Standards and Technology (NIST)","type":"government","accessed_at":"2026-09-18 18:01:11"},{"id":185,"title":"Ethereum Launches","url":"https://blog.ethereum.org/2015/07/30/ethereum-launches","publisher":"Ethereum Foundation Blog","type":"official","accessed_at":"2026-09-18 18:01:36"},{"id":186,"title":"Timeline of all Ethereum forks (2014 to present)","url":"https://ethereum.org/ethereum-forks/","publisher":"ethereum.org","type":"official","accessed_at":"2026-09-18 18:01:36"},{"id":187,"title":"Application-Specific Blockchains","url":"https://docs.cosmos.network/sdk/v0.53/learn/intro/why-app-specific","publisher":"Cosmos Documentation","type":"official","accessed_at":"2026-09-18 18:01:39"},{"id":188,"title":"CometBFT Documentation","url":"https://docs.cosmos.network/cometbft","publisher":"Cosmos Documentation","type":"official","accessed_at":"2026-09-18 18:01:39"},{"id":189,"title":"Private Networks","url":"https://geth.ethereum.org/docs/fundamentals/private-network","publisher":"Go Ethereum (Geth) Documentation","type":"official","accessed_at":"2026-09-18 18:01:39"},{"id":190,"title":"Chain Operator Configurations","url":"https://docs.optimism.io/operators/chain-operators/configuration/overview","publisher":"Optimism Docs","type":"official","accessed_at":"2026-09-18 18:01:42"},{"id":191,"title":"Client diversity","url":"https://ethereum.org/developers/docs/nodes-and-clients/client-diversity/","publisher":"ethereum.org","type":"official","accessed_at":"2026-09-18 18:01:43"},{"id":192,"title":"Ethereum Bug Bounty Program","url":"https://ethereum.org/bug-bounty/","publisher":"ethereum.org","type":"official","accessed_at":"2026-09-18 18:01:43"},{"id":173,"title":"Holesky and Hoodi Testnet Updates","url":"https://blog.ethereum.org/2025/03/18/hoodi-holesky","publisher":"Ethereum Foundation Blog","type":"official","accessed_at":"2026-09-18 18:01:28"}],"published_at":"2026-09-18 07:10:23"}