Facilitator Press · an imprint of Synthex Forge

x402 — The Agent Economy

Building and Selling Services Machines Will Pay For

A practitioner’s guide to building and selling services that AI agents discover, pay for, and consume — written from live x402 services on Base mainnet.

  • 121 pages
  • 19 code blocks
  • 12 chapters + 3 appendices
  • PDF · DRM-free
Cover of x402 — The Agent Economy

Your next customer might not be a person.

Agents are starting to buy things. They don’t sign up, don’t log in, don’t develop brand loyalty, and don’t fill out a form. They find a service, call it, pay for it in the same HTTP round-trip, and move on — often in under a second.

x402 is the payment rail that makes this possible. This book is the practitioner’s guide to actually shipping on it.

Written from live services

Built from a catalogue that is running now

Most writing about agentic commerce is theory. This isn't. It is built from a production catalogue of x402 services settling USDC on Base mainnet — including the parts that went wrong:

The IP leak

An origin server exposed through a reverse proxy — and how it was closed.

The placeholder endpoint

A stub that nearly got published to a paid catalogue as a real service.

The eight-hour deadlock

A lost worker lock that froze the whole build queue for a working day.

The fabricated revenue

A test that wrote invented numbers into a production store.

Those chapters exist because the author made those mistakes. Not because they read about them somewhere.

What you get

Exactly what arrives in the file

121 pages, 25,000 words12 chapters plus 3 appendices.
19 working code blocksServer skeleton, payment-verification flow, Ed25519 signing and verification, llms.txt and agent-card.json templates.
Real, measured market dataWhat's actually selling across a catalogue of ~2,900 services — with the numbers labelled honestly, including where they mislead.
The pricing chapterWhat machine buyers actually pay, from $0.001 to $2.00, and why price elasticity works differently when the buyer is software.
The discovery chapterThe part nobody tells you: a payment rail is not distribution.
A launch checklist and a full glossaryEverything you need to go from build to first paid call.
Who it’s for

Developers, AI engineers, and technical founders who can write code but haven’t shipped an x402 service yet. You need to be comfortable with HTTP and a terminal. You do not need to know anything about x402 going in.

Who it’s not for

People looking for hype, price predictions, or a get-rich-quick angle on AI. The economics chapter is deliberately unglamorous — most listings in this market earn approximately nothing, and the book says so plainly.

x402 — The Agent Economy

PDF · DRM-free, 121 pages. Yours to keep and read anywhere. The code in the appendices is plain Python you can run.

$29one-time · instant email delivery

Card payments are processed by Stripe. The PDF is emailed automatically once the payment clears.

Questions

Common questions

Do I need to know x402 already?

No. Chapter 2 explains the protocol from scratch.

Is this AI-generated fluff?

No. It's built from a real production catalogue with real incident post-mortems, and every market figure traces to a named measurement. Where something is the author's own estimate, it's labelled as such.

Will it still be relevant next year?

The protocol specifics may evolve; the discovery, pricing, and provenance chapters are structural and will outlast them.

Is there code?

Yes — 19 blocks, plain Python, all syntax-checked.

How is the book delivered?

Straight to your inbox as a PDF attachment, automatically, the moment your card payment confirms. No account, no login, and no download links that expire — the file is yours.

How do I pay?

By card only, through Stripe checkout. You are taken to Stripe to pay and we never see or store your card details. The book is emailed to you automatically once the payment clears.

Refunds?

If it doesn't teach you something you can act on, email enquiries@ziixcapital.com and ask for a refund.