[x402] Improve support for non-EVM chains like Nano

Hello again fellow Nano enthusiasts! 👋 Today I'm excited to share an early look at a new protocol specification I've been working on: **x402.NanoSession**. # What is it? In short: it's a draft/proposal of a standard that allows servers to charge for API requests or web resources on a*per-request* basis using Nano. No subscriptions, no credit card forms, no API keys. It builds upon the existing [x402 protocol](https://x402.org/) (which has been generating quite the buzz lately) and adapts it specifically for Nano's feeless, sub-second DAG architecture. # Why does this matter? Imagine an AI image generator or a premium data feed. Instead of forcing users to sign up for a $10/month subscription, the server simply replies to a request with an `HTTP 402 Payment Required` header specifying a tiny price (e.g., 0.05 XNO). The client automatically pays it, gets instant access, and the transaction settles directly over HTTP — no payment gateway, no middleman. Because Nano has **zero fees** and **sub-second finality**, it is arguably the *only* network perfectly suited for this kind of true Machine-to-Machine (M2M) micro-economy. This is just like, one of those things Nano was made to solve! And now we can see it in action. # How NanoSession solves the EVM problem The original x402 standards are heavily focused on EVM chains, relying on smart contracts and off-chain signatures (EIP-3009). Because Nano uses a block-lattice and changes account frontiers dynamically, those EVM assumptions fail entirely on our network. **NanoSession** bridges this gap. It introduces a highly secure "Session Binding" primitive where the server binds each session ID to a tag encoded in the least-significant digits of the Nano payment amount (the "dust"). This mitigates receipt-stealing attacks via mandatory session binding, while keeping the verification purely server-side and incredibly fast. # Check it out! This is a living proposal, and I would love to get your eyes on it! Are there edge cases I missed? Thoughts on the security model? * 📚 Read the spec, try the demo (mainnet, YOLO): [https://csi.ninzin.net/x402.NanoSession/](https://csi.ninzin.net/x402.NanoSession/) * 💻 Browse the code & POC server: [https://github.com/CasualSecurityInc/x402.NanoSession](https://github.com/CasualSecurityInc/x402.NanoSession) Let me know what you think! I truly believe Nano's zero-fee nature makes it the ultimate settlement layer for the upcoming agent economy, and protocols like this are the missing bridge. 🥦