A place for developers to talk about building on Farcaster.

/dev

🧵 Exploring x402: A Developer's Perspective

As some may know, we’ve been running some x402 agent experiments at Neynar the past few weeks. I like to call x402 agent blood. This is a serious paradigm shift in how agents will interact with the world. ITT we detail some of our findings.

🚀 Try It Today!

You can go right now to any of Neynar’s free-tier endpoints and access data using `sepolia` USDC.
https://api.neynar.com/v2/farcaster/cast?type=url&identifier=https://warpcast.com/horsefacts.eth/0x6b8e99f5

We’ll be watching to see what crazy ideas you come up with in the replies 😊

🔍 Middleware Compatibility

While x402 is designed to be tooling agnostic, we found that out-of-the-box middleware support was primarily available for Hono. To bridge this gap, we contributed an Express.js middleware, enhancing accessibility for a broader range of developer. There’s still some work to be done here though but rest assured Coinbase plans on beefing up the support before launch.

🛠️ Enhancing Developer Experience

During integration, we encountered some small issues with getting the package working in our environment. We fixed all the issues we found, but we haven’t tested in in every environment so expect some rough edges leading up to the full release. This is a great chance to help make the protocol more robust if you want to give integration a try.

💸 Transaction Costs and Facilitator Pricing

We observed that the managed facilitator imposes a hard minimum transaction cost of $0.0001. Implementing a hosted facilitator or utilizing a credit system may be necessary to achieve desired pricing models.

⚙ Flexible Payment Schemes
Right now x402 only supports exact EVM payments but it has the ability to support way more! In the future we expect Coinbase to roll-out balance based billing to drive per-request costs down.

👀The x402 protocol is setup to support payments using non-EVM schemes in the future 👀

This flexibility allows developers to implement whatever monetization strategies they can dream of. Carrier pigeon might be too high latency though.