Engineering
Engineering
How we build — paymasters, MPC key generation and the SDKs.
Bypassing the 3% Card Tax: How I Built an x402 Settlement Layer for AI Agents and Travelers on Arbitrum
A $340 resort checkout loses $11.90 to five intermediaries before it reaches the hotel — three days later. Here is how I built Furlpay's x402 settlement layer on Arbitrum instead: the actual contract code, measured gas benchmarks from the 34-test suite, the paymaster math behind zero-gas UX, and a direct answer to 'why not just use Stripe?'
July 8, 2026 · 11 min read
Arbitrum vs Base for Payments: Which Layer 2 Should You Settle On?
Both are strong Ethereum Layer 2s with sub-cent fees. For stablecoin payments the deciding factors are settlement finality, ecosystem maturity, and where institutional volume already lives. Here is the honest comparison.
July 6, 2026 · 6 min read
Integrating Furlpay with Arbitrum: Payments, x402 and Contracts on the Largest L2
Furlpay's settlement stack is going Arbitrum-first. Here is exactly what we shipped — an x402 facilitator that settles on Arbitrum, a unified USDC payments API, a chain registry, and four Solidity contracts with a green 17-test suite — and what ships next.
July 5, 2026 · 9 min read
Designing 2-of-2 MPC Key Generation for Self-Custody
No single private key is ever generated. Here's how Furlpay splits signing across a device passkey share and an HSM policy share.
June 28, 2026 · 6 min read
Bypassing the Gas Crisis: ERC-4337 Paymasters on L2 Networks
Nobody should need ETH just to send USDC. How Furlpay uses ERC-4337 account abstraction and Paymasters to make gas disappear.
June 15, 2026 · 5 min read
Solving Card Declines: Time-Locked Pre-Authorization Escrows
Why self-custodial cards get declined at gas pumps and hotels — and how Furlpay's time-locked escrow contracts fix pre-authorization holds.
June 1, 2026 · 5 min read
The Death of the Seed Phrase: WebAuthn & Device Trust
Furlpay replaces the 12-word seed phrase with phishing-resistant WebAuthn passkeys bound to your device's secure hardware.
May 28, 2026 · 5 min read