---
title: "What is x402 (PDF)"
url: "https://bip39-phrase.com/list-phrase/what-is-x402-2025-12-11/"
language: "en"
updated: "2026-10-24T00:00:00+00:00"
---

# What is x402

The internet economy has always struggled with payments. Traditional rails like credit cards and bank transfers were built for a physical world, and…

PDF document · Published December 11, 2025 · Updated October 24, 2026 

[ Open the PDF (3 pages, 69 KB) ](/list-phrase/what-is-x402-2025-12-11-en.pdf) 

## Contents

1. Example BIP39 word sequences
2. Reading a BIP39 phrase
3. See also

Topic: 

[BIP39 for Developers: Python Code, EVM Contracts and API Keys](/topics/developers/)

## Guides on the same subject

- [Smart Contract EVM: What It Is and How It Works](/smart-contract-evm-what-it-is-and-how-it-works/)  
The EVM is the sandboxed runtime every Ethereum node uses to run smart contracts: bytecode, gas, a Solidity example, real uses and the bugs that drain them.
- [What Is a Hot Wallet? How It Works, Types and Examples](/bitcoin-hot-wallet/)  
A hot wallet keeps its private keys on an internet-connected phone, computer or browser so it can sign at once. How it works, main types, examples and risks.
- [Bitcoin Pizza Day: The 10,000 BTC Pizza Story (May 22, 2010)](/bitcoin-for-pizza-story/)  
Bitcoin Pizza Day: on 22 May 2010, Laszlo Hanyecz paid Jeremy Sturdivant 10,000 BTC for two pizzas, the first real-world Bitcoin purchase.

One of the documents in the [Seed Phrase PDF Archive](/list-phrase/), listed on [archive page 8](/list-phrase/8/).