Understanding the Referent Metadata Hash

Oct 13, 2025 by wbrum.org 125 views

Introduction

When dealing with complex blockchain systems, upgrading contracts can be a daunting task. In this article, we will explore the upgrade path for non-fee token chains, specifically focusing on the 2.1.2 version of the Nitro contracts. We will delve into the requirements for this upgrade, the necessary steps, and the potential consequences of not following the recommended upgrade path.

Understanding the Referent Metadata Hash

Before we dive into the upgrade process, it's essential to understand the referent metadata hash of the Sequencer Inbox on 1.2.1 contracts. This hash is a unique identifier that can be used to determine the version of the deployed contract. In this case, the hash is:

1220e4fc6065f422acff75d4a2db15fdea38753da41cb0ce3dbafc57aecdc240

This hash can be obtained from the ETH and ERC20 fee token Orbit chain.

Determining the Fee Token Chain

When analyzing the contract versions, the following code snippet is used to determine if the chain is a fee token chain:

const { version, isErc20 } = _getVersionOfDeployedContract(
  metadataHashes[key]
)
versions[key] = version
if (isErc20) isFeeTokenChain = true

If the chain is determined to be a fee token chain, the isFeeTokenChain variable is set to true. This is crucial in determining the upgrade path for the chain.

Upgrade Path for Non-Fee Token Chain

When analyzing the contract versions, the following output is obtained:

Version of deployed Inbox: v1.1.0
Version of deployed Outbox: v1.1.0
Version of deployed SequencerInbox: v1.2.1
Version of deployed Bridge: v1.1.0
Version of deployed RollupEventInbox: unknown
Version of deployed RollupProxy: v1.1.0
Version of deployed RollupAdminLogic: v2.1.0
Version of deployed RollupUserLogic: v2.1.0
Version of deployed ChallengeManager: v2.1.0
This deployment can be upgraded to v2.1.2 using NitroContracts2Point1Point2UpgradeAction
✨  Done in 13.02s.

However, according to the documentation, the 2.1.2 upgrade is only required if the chain has a custom native token, was originally deployed before v2.0.0, and wishes to upgrade to v3.0.0 or v2.1.3. Since the chain is a non-fee token chain, this upgrade is not necessary.

Conclusion

In conclusion, the 2.1.2 upgrade path for non-fee token chains is not applicable in this scenario. The chain can be upgraded to v2.1.2 using the NitroContracts2Point1Point2UpgradeAction, but this is not a required upgrade. It's essential to carefully analyze the contract versions and follow the recommended upgrade path to avoid potential issues.

Recommendations

Always carefully analyze the contract versions before upgrading.
Follow the recommended upgrade path to avoid potential issues.
Ensure that the chain meets the requirements for the upgrade before proceeding.

Future Developments

As the blockchain ecosystem continues to evolve, new upgrades and features will be introduced. It's essential to stay up-to-date with the latest developments and best practices to ensure a smooth and secure upgrade process.

References

Nitro contracts 2.1.2 upgrade guide
Understanding the referent metadata hash
Determining the fee token chain
2.1.2 Upgrade Path for Non-Fee Token Chain: Q&A =====================================================

Introduction

In our previous article, we explored the upgrade path for non-fee token chains, specifically focusing on the 2.1.2 version of the Nitro contracts. However, we received many questions from our readers regarding the upgrade process. In this article, we will address some of the most frequently asked questions (FAQs) related to the 2.1.2 upgrade path for non-fee token chains.

Q: What is the referent metadata hash, and how is it used?

A: The referent metadata hash is a unique identifier that can be used to determine the version of the deployed contract. It is obtained from the ETH and ERC20 fee token Orbit chain. The hash is used to determine if the chain is a fee token chain, which is crucial in determining the upgrade path.

Q: How do I determine if my chain is a fee token chain?

A: To determine if your chain is a fee token chain, you need to analyze the contract versions. The following code snippet is used to determine if the chain is a fee token chain:

const { version, isErc20 } = _getVersionOfDeployedContract(
  metadataHashes[key]
)
versions[key] = version
if (isErc20) isFeeTokenChain = true

If the chain is determined to be a fee token chain, the isFeeTokenChain variable is set to true.

Q: What is the 2.1.2 upgrade path for non-fee token chains?

A: The 2.1.2 upgrade path for non-fee token chains is not applicable in this scenario. The chain can be upgraded to v2.1.2 using the NitroContracts2Point1Point2UpgradeAction, but this is not a required upgrade.

Q: What are the requirements for the 2.1.2 upgrade?

A: According to the documentation, the 2.1.2 upgrade is only required if the chain has a custom native token, was originally deployed before v2.0.0, and wishes to upgrade to v3.0.0 or v2.1.3.

Q: Can I upgrade my chain to `v2.1.2` if it's not a fee token chain?

A: Yes, you can upgrade your chain to v2.1.2 using the NitroContracts2Point1Point2UpgradeAction, but this is not a required upgrade.

Q: What are the potential consequences of not following the recommended upgrade path?

A: Not following the recommended upgrade path can lead to potential issues, such as:

Incompatibility with other contracts
Data loss or corruption
Security vulnerabilities

Q: How can I ensure a smooth and secure upgrade process?

A: To ensure a smooth and secure upgrade process, follow these best practices:

Always carefully analyze the contract versions before upgrading.
Follow the recommended upgrade path to avoid potential issues.
Ensure that the chain meets the requirements for the upgrade before proceeding.

Conclusion

In conclusion, the 2.1.2 upgrade path for non-fee token chains is not applicable in this scenario. However, we hope that this Q&A article has provided valuable information and insights to help you navigate the upgrade process. Remember to always carefully analyze the contract versions and follow the recommended upgrade path to ensure a smooth and secure upgrade process.