> ## 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

<Warning>
  **Use `2.2.3` (Nexus 1.3.3) for all new accounts.** Nexus versions before 1.3.3 have a re-initialization issue, fixed in 1.3.3 by making account initialization single-use per transaction. The earlier suites below are listed only to derive the address of accounts already created on them. Do not deploy new accounts with them.

  Version numbers do not indicate which suite to use: `2.3.0` is numbered above `2.2.3` but is an unaudited release candidate built on Nexus 1.3.1.
</Warning>

<Accordion title="MEE Contracts Suite v2.2.3 (current)">
  <Info>
    **What's New:**

    * Nexus 1.3.3. Account initialization is single-use per transaction
    * Bundles the audited [ERC-8211 Smart Batching](https://www.erc8211.com) reference implementation (Ethereum Foundation & Biconomy)
    * Reviewed by Pashov Audit Group (July 2026)

    This is the version to use for newly created accounts. See [Account Migration](/upgrade-migrate) for what this means for accounts you already have.
  </Info>

  ### Nexus & MEE

  | Contract Name | Contract Address |
  | - | - |
  | Nexus Implementation v1.3.3 | `0x0000B1c01cB3b5770D8806f0D214d50131a08a5B` |
  | MEE K1 Validator v1.1.0 | `0x0000B1C0790E5a28293276C320d2B95D651dBaD6` |
  | Nexus Bootstrap v1.3.0 | `0x0000B1c0A80cb7DD166a15e7390b8A4Ced4500C6` |
  | Nexus Account Factory | `0x0000b1C08f1418dA76B5E99c1Bf5718486cf8c53` |

  ### 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` |

  <Note>
    Only the Nexus implementation and the account factory change in this release. The bootstrap, validator, ERC-8211 and utility contracts are byte-identical to v2.2.2 and keep their existing addresses.
  </Note>
</Accordion>

<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. It is built on Nexus 1.3.1, not 1.3.3, and is not intended for production accounts.
  </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 (superseded)">
  <Warning>
    Superseded by v2.2.3. Nexus 1.3.2 has the re-initialization issue fixed in 1.3.3. Do not use for new accounts; these addresses are listed only for deriving addresses of accounts already created on this version.
  </Warning>

  <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 (superseded)">
  <Warning>
    Superseded by v2.2.3. Nexus 1.3.1 has the re-initialization issue fixed in 1.3.3. Do not use for new accounts; these addresses are listed only for deriving addresses of accounts already created on this version.
  </Warning>

  <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">
  <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>


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