Create x402-substrate.md

[ShankarWarang]

Project Abstract

x402 Substrate SDK & Facilitator Network aims to bring the x402 HTTP 402-native payment protocol to the whole Polkadot ecosystems. The project delivers two core JavaScript/TypeScript libraries: an x402 SDK for client-side payment integration and an x402 Facilitator service for server-side payment verification and settlement. This addresses a critical infrastructure gap, as x402 has achieved significant product-market fit on Solana (500,000+ weekly transactions as of October 2025) and limited EVM support via Base, but no native PolkadotSDK(Substrate) implementation exists.​

The x402 protocol enables any HTTP API to require blockchain-backed micropayments before serving resources with zero protocol fees and millisecond settlement times, a significant advantage over traditional payment processors that charge 2.9% + $0.30 per transaction. The Substrate implementation is specifically optimized for Polkadot's architecture (starting with AssetHub), supporting native PAS/DOT/KSM tokens, custom tokens via pallet-assets, and cross-chain settlement via XCM interoperability, all without requiring new pallet code or governance approval. Over a four-month timeline with a budget of $29,040 USD, the Edgetributors team plans to deliver the client SDK, facilitator service, multi-chain support (for common-good and commercial parachains of Polkadot & Kusama), comprehensive documentation, security hardening, and community examples - positioning x402 as critical infrastructure for the next wave of Web3 developer tools in the Polkadot ecosystem.

Application Checklist

• The application template has been copied and aptly renamed (project_name.md).
• I have read and followed the program guidelines.
• I am aware that, in order to receive a grant, I (and the entity I represent) have to successfully complete a KYC/KYB check.
• The software delivered for this grant will be released under an open-source license specified in the application.

[ditavia-br]

@ShankarWarang Thanks for the application. We are nearing the end of our runway, so we’ll need to wait for clarity on the budget before moving forward with any remaining applications. We’ll get in touch as soon as we have an update.