Important Version Upgrade

FIO Blog
Published in
2 min readSep 10, 2020


All FIO producer, API, and history nodes must be upgraded to Version 2.0.0 by September 16, 2020

FIO has been active over the past few months working on the FIO Improvement Proposals (FIPs), but there has been a noticeable lack of FIO feature releases.

Early in the release schedule, the FIO development team encountered a core design issue that, if not corrected, would have forced updates to the FIO core chain code for every feature release.

The design issue is related to how FIO whitelists public contract actions as part of chain security. FIO’s initial design had this whitelist hardcoded in chain code instead of being maintained in state. Version 2.0.x is a required update that introduces FIP-12 ( which moves the whitelisted actions table into state.

This will significantly simplify and accelerate the release of new features in the future. Because this is a required update, FIO nodes that have not upgraded by September 16 will be forked off of the primary chain.

The Version 2.0 rollout schedule:

  • Milestone 1 (Aug-14) — Announce release and schedule to FIO community.
  • Milestone 2 (Sep-4) — All Mainnet nodes must be upgraded to v2.0
  • Milestone 3 (Sep-11) — FIP-12 system contract approved on Mainnet. This enables the calling of addaction/remaction.
  • Milestone 4 (Sep-16) — Mainnet forking transaction: actions table updates submitted to Mainnet. All FIO producer, API, and history nodes must be upgraded by this date.
  • Milestone 5 (Wed Sep 23 16:00:00 UTC 2020 ) — The new actions table needs to be populated with all of the allowed actions in the fio protocol.

Version 2.0 has been fully tested by FIO block producers in Testnet ( and Mainnet upgrades to v2.0 are in progress.



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