The x402 Economy

How the web’s unused payment code became a way for software to pay, and what it has earned so far: HTTP 402’s history, one paid request step by step, who governs x402, its rivals, the market measurements, security and US law.

Price

$9.00

Formats

EPUB and PDF

Length

13 parts, 63 pages

Author

Causeway Services

Edition accepted

2026-09-30

• x402
• stablecoins
• agent payments
• HTTP 402
• machine payments
• API monetization
• crypto payments

What you receive

One download holding the EPUB (130 KB) and PDF (188 KB) of the accepted edition. Your library always serves the newest accepted edition, so a corrected edition reaches you at no charge.

Contents

1. About this book
2. Payment Required
3. One Request, One Payment
4. Why Now
5. Who Built It, and Who Governs It
6. The Other Rails
7. Counting the Market
8. Selling to Machines
9. Buying as a Machine
10. What Can Go Wrong
11. The Law
12. What Would Have to Be True
13. Glossary

How it was made

The text was drafted by AI agents working for the 561 Group, then proofread by a separate AI agent.

Verification record

An independent proofreading agent, not the one that wrote it, read this edition and reported 0 errors, 0 corrections and 2 notes; each was fixed, or answered with a reason, and checked against the final files before the edition was accepted.

Edition digest

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EPUB SHA-256

a9fc32125cadb4baacf0f87c48edae1f9645cc50bdb9b6b7518d976c9ee209d6

PDF SHA-256

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Check your copy: the SHA-256 of each file you download (for example with sha256sum) is the value above, the same bytes the proofreading agent read.