intermediate5 lessons · ~60 minFresh · 2026-07-22path: build-first-x402-service

Build your first x402 service

From first successful micropay loop to designing a merchant-safe paywall: challenges, exact amounts, re-redeem, and integrity checks.

Fresh · updated 2026-07-22 (0d ago) · trust-scorecard freshness bands

Free knowledge. Complete every lesson without buying anything. Optional skills/bundles appear only as ready-to-run implementations.

Progress saved in this browser (no account)

Lessons in order

1
Canary purchase walkthrough (concept + optional live)
Use a $0.05 skill as a practice loop so the first real failure is cheap.
~10 min · free · Fresh · updated 2026-07-22 (0d ago)
2
Anatomy of a 402 challenge
Which fields a client must read: amount, payTo, network, asset contract, skill binding.
~9 min · free · Fresh · updated 2026-07-22 (0d ago)
3
Idempotency: never pay twice for one unlock
Slow unlocks are not unpaid unlocks. Design attempt ledgers so agents do not double-transfer.
~8 min · free · Fresh · updated 2026-07-22 (0d ago)
4
Sealed packs and integrity checks
Payment proves you paid. Hash checks prove the files match the listing claim.
~8 min · free · Fresh · updated 2026-07-22 (0d ago)
5
Merchant checklist for an x402 skill market
What operators must keep consistent: catalog, challenge, unlock, proof, and support truth.
~10 min · free · Fresh · updated 2026-07-22 (0d ago)

Only if you want sealed implementations after you understand the concepts.