x402 V1 → V2 Migration Guide Field notes from migrating a live, payment-gated API from...
x402 V1 → V2 Migration Guide
Field notes from migrating a live, payment-gated API from x402 V1 to V2 on Base mainnet — the undocumented gotchas, working code from a service in production, and a checklist at the bottom.
Written from x402ai, which settles real USDC on Base via the Coinbase CDP facilitator. Every code sample here is running in production, not reconstructed from the spec.
Last verified: July 2026 · @x402/* 2.19.0 · @coinbase/x402 2.1.0
In a hurry? → Migration checklist
We run FiatDock — a non-custodial USDC ↔ bank on/off-ramp where AI agents pay $0.05 per call over...
A packet-level walkthrough of one x402 API payment, showing where payment proof ends and where agent policy, replay handling,…
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Coinbase's x402 protocol hit 100 million agentic transactions on Base in nine months, with $24.24M in recent 30-day volume as…
On 2026-05-19 Base launched mcp.base.org — their official MCP server that connects your Base Account...
