> ## Documentation Index
> Fetch the complete documentation index at: https://docs.biconomy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Contracts & Audits

> Verified smart contract addresses and security audit reports for MEE protocol

<Note>
  Always verify contract addresses from official sources before interacting with them
</Note>

## Contract Suite

Biconomy is versioning our smart contracts by groups. One "Suite" version contains many different versioned contracts
within itself.

The contracts being versioned are:

* Nexus Account
* Modular Execution Environment (MEE) K1 Validator (ERC-7579 Module)
* Nexus Boostrap & Factory
* Composability & Fusion Utils (Composable Storage, ETH Forwarder)

## Versions

<Accordion title="MEE Contracts Suite v2.3.0 (rc)">
  <Info>
    **What's New:**

    * New fusion mode `safe-sa` which allows using Safe accounts as master accounts instead of EOAs

    **Attention!** This version utilizes unaudited cotracts.
  </Info>

  ### Nexus & MEE Validator

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.3.1 | `0x54F220e4f0DEAb58Be26153df5a674668B9d7Fb2` |
  | MEE K1 Validator v1.2.0     | `0x1Cdae7dcc3f32551865EfE3d77AC2b88Ee2905B4` |
  | Nexus Bootstrap v1.3.0      | `0xCa8f48912A3a33fE694c318a1d097AD394CFAB76` |
  | Nexus Account Factory       | `0x5836Bdb35913c7CBA6ef40675354445121449917` |
</Accordion>

<Accordion title="MEE Contracts Suite v2.2.2">
  <Info>
    **What's New:**

    * Bundles the audited [ERC-8211 Smart Batching](https://www.erc8211.com) reference implementation (Ethereum Foundation & Biconomy) — the formal standardization of the composability primitives shipped in earlier versions
    * Expanded composability primitives and pipeline hardening
    * Audited by Pashov (May 2026)
  </Info>

  ### Nexus & MEE

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.3.2 | `0x0000b1C0B95DA04652C1919667D1DCC14f46f62B` |
  | MEE K1 Validator v1.1.0     | `0x0000B1C0790E5a28293276C320d2B95D651dBaD6` |
  | Nexus Bootstrap v1.3.0      | `0x0000B1c0A80cb7DD166a15e7390b8A4Ced4500C6` |
  | Nexus Account Factory       | `0x0000B1c0dCFd64dfe8FeC844923B653DD0dfdB05` |

  ### ERC-8211

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Composable Execution Module | `0x0000821108B5C9F3fe17E40811bE5b66DaF8f0e7` |
  | Composable Storage          | `0x00008211dea1Aca67ac55fc44AE3bF88CF41281d` |

  ### Utility

  | Contract Name          | Contract Address                             |
  | ---------------------- | -------------------------------------------- |
  | ETH Forwarder          | `0x0000B1C0Fc7015Effa85892426FAEd8211B2d62E` |
  | Node Paymaster Factory | `0x0000B1C059753ae6d1C135605377cE6487385960` |
</Accordion>

<Accordion title="MEE Contracts Suite v2.2.1 (latest)">
  <Info>
    **What's New:**

    * New composability version - enables native token runtime injection
    * Sign EIP-712 Data Struct instead of blind Stx hash for the `smart-account` mode
    * New ERC-7702 Nexus accounts can be initialized via relayers
    * Gas optimizations
  </Info>

  ### Nexus & MEE Validator

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.3.1 | `0x0000000020fe2F30453074aD916eDeB653eC7E9D` |
  | MEE K1 Validator v1.1.0     | `0x0000000002d3cC5642A748B6783F32C032616E03` |
  | Nexus Bootstrap v1.3.0      | `0x000000007BfEdA33ac982cb38eAaEf5D7bCC954c` |
  | Nexus Account Factory       | `0x000000002c9A405a196f2dc766F2476B731693c3` |

  ### Composability & Utility

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Composable Execution Module | `0x00000000f61636C0CA71d21a004318502283aB2d` |
  | Composable Storage          | `0x0000000078994c6ef6A4596BE53A728b255352c2` |
  | ETH Forwarder               | `0x000000C48Cdf2b46bEc062483dBD27046dfE3b8d` |
</Accordion>

<Accordion title="MEE Contracts Suite v2.1.0 (Current Default)">
  <Info>
    **What's New:** K1 MEE module introduced - enables ERC-7702-delegated EOAs to own Nexus accounts
  </Info>

  ### Nexus & MEE Validator

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.2.0 | `0x00000000383e8cBe298514674Ea60Ee1d1de50ac` |
  | MEE K1 Validator v1.0.3     | `0x0000000031ef4155C978d48a8A7d4EDba03b04fE` |
  | Nexus Bootstrap v1.2.1      | `0x0000003eDf18913c01cBc482C978bBD3D6E8ffA3` |
  | Nexus Account Factory       | `0x0000006648ED9B2B842552BE63Af870bC74af837` |

  ### Composability & Utility

  | Contract Name      | Contract Address                             |
  | ------------------ | -------------------------------------------- |
  | Composable Storage | `0x0000000671eb337E12fe5dB0e788F32e1D71B183` |
  | ETH Forwarder      | `0x000000Afe527A978Ecb761008Af475cfF04132a1` |
</Accordion>

<Accordion title="MEE Contracts Suite v2.0.0">
  <Info>
    Major release with Nexus 1.2.0, ERC-7702 support, and native composability
  </Info>

  ### Nexus & MEE

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.2.0 | `0x000000004F43C49e93C970E84001853a70923B03` |
  | MEE K1 Validator v1.0.1     | `0x00000000d12897DDAdC2044614A9677B191A2d95` |
  | Nexus Bootstrap v1.2.1      | `0x00000000D3254452a909E4eeD47455Af7E27C289` |
  | Nexus Account Factory       | `0x000000001D1D5004a02bAfAb9de2D6CE5b7B13de` |
  | MEE EntryPoint & Paymaster  | `0xE854C84cD68fC434cB3B0042c29235D452cAD977` |

  ### Composability & Utility

  | Contract Name      | Contract Address                             |
  | ------------------ | -------------------------------------------- |
  | Composable Storage | `0x0000000671eb337E12fe5dB0e788F32e1D71B183` |
  | ETH Forwarder      | `0x000000Afe527A978Ecb761008Af475cfF04132a1` |
</Accordion>

<Accordion title="MEE Contracts Suite v1.1.0 Pre-cancun">
  <Info>
    Compiled for **EVM Paris** (No PUSH0, no MCOPY, no TSTORE)
  </Info>

  ### Nexus & MEE

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.0.2 | `0x000000001964d23C59962Fc7A912872EE8fB3b6A` |
  | MEE K1 Validator v1.0.3     | `0x00000000E894100bEcFc7c934Ab7aC8FBA08A44c` |
  | Nexus Bootstrap v1.0.0      | `0x000000c4781Be3349F81d341027fd7A4EdFa4Dd2` |
  | Nexus Account Factory       | `0x0000000C8B6b3329cEa5d15C9d8C15F1f254ec3C` |

  ### Composability & Utility

  | Contract Name        | Contract Address                             |
  | -------------------- | -------------------------------------------- |
  | Composability Module | `0x000000Fc19Cf049b445dd5CC0D590f6f93075f42` |
  | Composable Storage   | `0x000000d2520640d0993B58112b929e71C9747300` |
  | ETH Forwarder        | `0x000000001f1c68bD5bF69aa1cCc1d429700D41Da` |
</Accordion>

<Accordion title="MEE Contracts Suite v1.0.1">
  <Info>
    Added Nexus Account Factory at `0x000000903887EA36EBe051038287f49fD4A07733`
  </Info>
</Accordion>

<Accordion title="MEE Contracts Suite v1.0.0">
  <Info>
    Initial release - Requires manual installation of MEE K1 validator and Composability module
  </Info>

  [GitHub Release →](https://github.com/bcnmy/nexus/releases/tag/v1.0.2)

  ### Nexus & MEE

  | Contract Name               | Contract Address                             |
  | --------------------------- | -------------------------------------------- |
  | Nexus Implementation v1.0.2 | `0x000000aC74357BFEa72BBD0781833631F732cf19` |
  | MEE K1 Validator v1.0.1     | `0x00000000d12897DDAdC2044614A9677B191A2d95` |
  | Nexus Bootstrap v1.0.0      | `0x879fa30248eeb693dcCE3eA94a743622170a3658` |
  | Nexus Account Factory       | `0x000000c3A93d2c5E02Cb053AC675665b1c4217F9` |
  | MEE EntryPoint & Paymaster  | `0xE854C84cD68fC434cB3B0042c29235D452cAD977` |

  ### Composability & Utility

  | Contract Name        | Contract Address                             |
  | -------------------- | -------------------------------------------- |
  | Composability Module | `0x00000004430bB055dB66eBef6Fe5Ee1DA9668B10` |
  | Composable Storage   | `0x0000000671eb337E12fe5dB0e788F32e1D71B183` |
  | ETH Forwarder        | `0x000000Afe527A978Ecb761008Af475cfF04132a1` |
</Accordion>

### Nexus Audits

<CardGroup cols={4}>
  <Card title="Cyfrin" icon="shield" href="https://github.com/bcnmy/nexus/blob/main/audits/CodeHawks-Cyfrin-Competition-170924.pdf">
    Competition Audit
  </Card>

  <Card title="Spearbit" icon="shield">
    * [Core audit](https://github.com/bcnmy/nexus/blob/main/audits/report-cantinacode-biconomy-0708-updated.pdf)
    * [ERC-7739](https://github.com/bcnmy/nexus/blob/main/audits/report-cantinacode-biconomy-erc7739-addon-final.pdf)
  </Card>

  <Card title="Zenith" icon="shield" href="https://github.com/bcnmy/nexus/blob/main/audits/Biconomy-Nexus_Zenith-Audit-Report.pdf">
    Full Review
  </Card>

  <Card title="Pashov" icon="shield" href="https://github.com/bcnmy/nexus/blob/main/audits/Nexus-Pashov-Review_2025-03.pdf">
    2025 Review
  </Card>
</CardGroup>

### MEE Stack Audits

<CardGroup cols={2}>
  <Card title="MEE Stack" icon="layer-group" href="https://github.com/bcnmy/mee-contracts/tree/main/audit">
    **Audited by Zenith**

    * MEE EntryPoint
    * Node Paymaster
    * MEEK1 Validator
  </Card>

  <Card title="Composability Stack" icon="puzzle">
    **Multiple Auditors**

    * [Pashov Report (2026-05, ERC-8211 / v2.2.2)](https://github.com/bcnmy/erc8211-contracts/blob/main/audits/2026-05-Composability-Nexus-Pashov-Review.pdf) — covers the audited submodule pinned in v2.2.2 (signed constraints, `IN_SIGNED`, OR composition, `SKIP`, pipeline hardening)
    * [Zenith Report (2025-03)](https://github.com/bcnmy/composability/blob/main/audits/2025-03-Composability_Zenith-Audit-Report.pdf)
    * [Pashov Report (2025-03)](https://github.com/bcnmy/composability/blob/main/audits/2025-03-Composability-Pashov-Review.pdf)
  </Card>
</CardGroup>

***

## Legacy Contracts

<Warning>
  These contracts are deprecated. Use the latest version for new deployments.
</Warning>

<Accordion title="Nexus v1.0.1 Production">
  | Contract Name        | Contract Address                             |
  | -------------------- | -------------------------------------------- |
  | Nexus Implementation | `0x000000008761E87F023f65c49DC9cb1C7EdFEaaf` |
  | K1 Validator         | `0x0000002D6DB27c52E3C11c1Cf24072004AC75cBa` |
  | K1 Validator Factory | `0x00000024115AA990F0bAE0B6b0D5B8F68b684cd6` |
  | Account Factory      | `0x000000226cada0d8b36034F5D5c06855F59F6F3A` |
  | Bootstrap            | `0x000000F5b753Fdd20C5CA2D7c1210b3Ab1EA5903` |
  | EntryPoint V7        | `0x0000000071727de22e5e9d8baf0edac6f37da032` |
</Accordion>

<Accordion title="Paymaster Contracts">
  ### Base & Optimism

  | Contract Name         | Contract Address                             |
  | --------------------- | -------------------------------------------- |
  | Sponsorship Paymaster | `0x0000006087310897e0BFfcb3f0Ed3704f7146852` |
  | Token Paymaster       | `0x00000000301515A5410e0d768aF4f53c416edf19` |

  ### Other Chains

  | Contract Name         | Contract Address                             |
  | --------------------- | -------------------------------------------- |
  | Sponsorship Paymaster | `0x00000072a5F551D6E80b2f6ad4fB256A27841Bbc` |
  | Token Paymaster       | `0x00000000301515A5410e0d768aF4f53c416edf19` |
</Accordion>