Upcoming ArbOS Upgrade for Testnet (Except Plume Testnet)

We’re excited to announce that ArbOS 51 (Dia) is now ready for adoption! This upgrade brings important improvements from the Ethereum Fusaka upgrade and more.

What’s Included

• Features from ArbOS 40 (Callisto) upgrade if your chain is currently on ArbOS 32

• Unlocks the path to Permissionless Fault Proofs in the future with the new BoLD dispute protocol

• Unlocks the path to enabling Native Token Mint/Burn capabilities

• EIP-7825 - Transaction gas limit cap - More efficient gas usage

• Bunch of precompiles/opcode changes that make cryptographic operations cheaper and more efficient in the EVM

• For a full breakdown, see the upgrade notice.

Required Actions

• No action required if you are not running external nodes.

• If you or your partners are running external nodes, you must upgrade your Nitro node's version to atleast v3.9.3 but v3.9.5 (release link) is recommended. Also make sure the flag --node.staker.enable=false is configured on your node.

  
  

Readiness Schedule
You need to have your nodes upgraded before these dates:

• Testnet: Wed 4th Feb 2026 07:30:00 UTC

Post Upgrade
After the upgrade is done, your chain’s chainInfo.json file will have been updated. We recommend downloading the latest version from the Conduit Dashboard and using it in your external node moving forward.

Questions?
If you have any questions, feel free to contact Conduit Support through your usual channels or at support@conduit.xyz.

P.S. This upgrade is excluding Plume testnet which has been upgraded already.