The Modular Execution Environment (MEE) supports multiple versions of its contract suite. Each version introduces new capabilities around smart accounts, validator configuration, and composability.
This guide helps SDK developers understand and select the appropriate version for their use case.

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Versions Table

The table below outlines all supported MEE versions and their core capabilities. Use this to determine the best version for your project based on EVM support, composability, and ERC-7702 compatibility.
VersionNexus VersionERC-7702 SupportComposabilityNotes
2.1.01.2.0✅ Yes✅ NativeLatest and recommended. Allows delegated/upgraded EOAs to directly own smart accounts in Nexus 1.2.0.
2.0.01.2.0✅ Yes✅ NativeSupports ERC-7702 flows but does not support delegated/upgraded EOAs as direct owners of smart accounts.
1.1.01.0.2❌ No⚠️ ManualComposability must be installed manually (handled by the SDK). Best for EVM Paris–only chains with limited opcode support.
1.0.01.0.2❌ No⚠️ ManualSame as 1.1.0. Composability module installed via SDK.

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Version Breakdown

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Recommendation

For most development needs, version 2.1.0 is strongly recommended due to its full support for delegated EOAs and native composability. Earlier versions remain available for legacy or specialized chains but require additional setup steps handled by the SDK. 
import { MEEVersion } from "@your-sdk/core";

const version = MEEVersion.V2_1_0;

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How to Find Your Current Nexus Version

Not sure which Nexus version your smart account is using? Follow these simple steps to find out:
1

Locate your smart account address

Locate your existing Nexus smart account address on the specific blockchain you’re working with.
2

Open the block explorer

Open the block explorer for that chain (e.g., Etherscan, Polygonscan) and paste the smart account address into the search bar.
3

Navigate to the Contracts tab

Navigate to the Contracts tab on the explorer page.
4

Verify the proxy contract if needed

If the contract is a proxy and the proxy contract isn’t verified yet, you’ll need to verify it first. (If “Read as proxy” option isn’t available, this usually means verification is needed.)
5

Call the getImplementation function

Once verified, go to the Read as proxy section and call the getImplementation function. This will return the address of the actual implementation contract your smart account is using.
6

Compare with official addresses

Compare this implementation contract address against the addresses listed on our Contracts and Audits page. This will help you identify exactly which MEE version you are using.
If you need further assistance, feel free to join our Discord community and ask for help!
Keeping track of your Nexus version is key for smooth upgrades and compatibility checks.

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Not Sure Which Version to Choose?

If you’re still confused about which MEE version fits your needs, or if you’re unsure about your current version for migration, don’t worry! Join our Discord community to ask questions and get real-time support from the team and other developers. We’re here to help you choose the best path forward!