> For the complete documentation index, see [llms.txt](https://quackai.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://quackai.gitbook.io/docs/q402-execution-layer/proposalgeneration.md).

# Q402 Architecture

Q402 is Quack AI’s gasless payment protocol built on EIP-7702 + EIP-712. It enables one-signature, gasless transactions with any existing ERC-20 token across 7 EVM mainnets — eliminating the ERC-3009 dependency that limits other gasless payment implementations.

Q402 evolved from Quack AI’s October 2025 launch of x402 BNB, the first unified sign-to-pay layer for BNB Chain’s Agent Economy. The same EIP-7702 + EIP-712 architecture has since been expanded into a unified multi-chain protocol, now live on Ethereum, BNB Chain, Avalanche C-Chain, X Layer, Mantle, Stable, and Injective EVM.

The Q402 roadmap includes future interoperability with the broader x402 ecosystem, enabling cross-protocol Agent Economy coordination.

<figure><img src="/files/ppm5SiDSrR4YtmET2bPH" alt=""><figcaption></figcaption></figure>

#### Core Framework

| Version | Network Focus                                                                                   | Technical Standard                                        | Key Innovation                                                                                         |
| ------- | ----------------------------------------------------------------------------------------------- | --------------------------------------------------------- | ------------------------------------------------------------------------------------------------------ |
| Q402    | 7 EVM mainnets (Ethereum, BNB Chain, Avalanche C-Chain, X Layer, Mantle, Stable, Injective EVM) | EIP-7702 Delegated Execution + EIP-712 Witness Signatures | Unified sign-to-pay protocol — supports any ERC-20 with no token upgrades, fully gasless, policy-aware |

#### Why Q402 Matters

Q402 provides a universal execution fabric for the Agent Economy, where governance, payments, and compliance operate under one rule-driven standard.\
It ensures that on-chain actions — from DAO votes to RWA settlements — can be completed with one verifiable signature and zero gas friction.

#### Architecture Overview

| Component                    | Function                                                                                                                   |
| ---------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
| Signature Layer (EIP-712)    | Captures user intent and cryptographically binds payment or governance data.                                               |
| EIP-7702 Delegated Execution | Enables facilitators to submit Type 0x04 set-code transactions on user EOAs, supporting any ERC-20 without prior approval. |
| Facilitator Network          | Manages gas sponsorship, monitors compliance, and maintains verifiable receipts.                                           |
| Policy Engine Hooks          | Validates every action against expiry, limits, and whitelisted conditions.                                                 |
| Audit Registry               | Records signature-to-transaction mappings for on-chain traceability and reporting.                                         |

#### Q402 Production Deployment

* Live deployment across 7 EVM mainnets with verified contract addresses
* Supports any ERC-20 token without requiring upgrades
* Achieved near-zero transaction failure rate
* Reduced governance settlement latency by over 70%
* Established compliance and audit-ready proof of execution
* Production endpoint live at q402.quackai.ai with full SDK and developer platform

#### The Path Forward

Q402 continues to evolve. Upcoming developments include:

* CCTP-native USDC support on Injective EVM (announced for Q2 2026)
* Enhanced policy modules for regulated RWA flows
* Cross-chain facilitator registry expansion
* Deeper integration with AI Agent Governance for autonomous settlement