HTTPayer
Pay server for automated x402 payments
Created on 29th June 2025
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HTTPayer
Pay server for automated x402 payments
The problem HTTPayer solves
The current landscape of onchain payments and monetization is fragmented,
complex, and often inaccessible to both developers and end users. Traditional
payment systems are ill-suited for microtransactions, cross-chain value
transfer, and the programmable finance required by modern DeFi, tokenization,
and AI-driven applications. Developers face high integration barriers, limited
interoperability, and a lack of secure, automated solutions for monetizing APIs
and digital services.
HTTPayer solves these challenges by providing a unified, secure, and
developer-friendly platform for onchain payments and monetization. Leveraging
the x402 protocol, EIP-3009 signatures, and Chainlink CCIP, HTTPayer enables
seamless, automated, and cross-chain payments for API calls and digital
services. The current deployment targets are the Base Sepolia and Avalanche Fuji
(C-Chain) testnets, ensuring robust support for multi-chain development and
testing. This unlocks new possibilities for pay-per-use business models,
decentralized applications, and AI agent interactions—without relying on legacy
payment processors or centralized intermediaries.
By abstracting away the complexity of crypto payments, HTTPayer empowers
developers to easily integrate stablecoin (USDC) microtransactions across
multiple EVM chains, opening the door to a new era of global, permissionless,
and composable onchain finance. The platform is designed to be extensible,
supporting future innovations in DeFi, tokenized assets, and cross-chain
interoperability, and positioning itself as a foundational layer for the next
generation of Web3 and AI-powered economies.
Challenges we ran into
During development, we encountered several notable challenges that shaped the
evolution of HTTPayer's architecture and implementation:
EIP-3009 Messaging in Python
Our initial approach was to implement EIP-3009 messaging in Python, aiming for a
unified backend. However, we found that Python's ecosystem lacked robust
libraries and tooling for EIP-3009 and related Ethereum signature standards.
This led to recurring issues with message encoding and signature verification,
which risked the reliability of payment flows. To address this, we rewrote the
primary payment orchestration server in TypeScript, leveraging the mature
Ethereum tooling available in the Node.js ecosystem. This decision significantly
improved our ability to handle x402 protocol flows and ensured compatibility
with EIP-712 and EIP-3009 standards.
Initial Deployment Issues
Deploying the early versions of HTTPayer surfaced several operational
challenges, including environment inconsistencies and dependency conflicts
between the TypeScript and Python services. These issues occasionally led to
service downtime and complicated the deployment pipeline. By consolidating
critical payment logic in TypeScript and containerizing all services, we
achieved a more stable and reproducible deployment process, as documented in our
architecture and backend guides.
Avalanche Integration
Integrating Avalanche Fuji as a supported chain was a key milestone. While the
process was smoother than anticipated, it required the development of a custom
facilitator service. The default x402 facilitator was designed for Base Sepolia
and did not support Avalanche's network parameters or consensus specifics. By
implementing a dedicated facilitator server for Avalanche, we ensured seamless
multi-chain support and future extensibility for additional EVM-compatible
networks.
Tracks Applied (3)
Onchain Finance
Cross-Chain Solutions
Avalanche Track
Avalanche
Technologies used