Quick Start

Get started with Book402 in under 5 minutes.

1. Browse (Free)¶

No setup needed — free endpoints work with any HTTP client:

# Search books by keyword
curl "https://book402.com/books?q=habits"

# Get a specific book
curl "https://book402.com/books/42"

# List all genres
curl "https://book402.com/genres"

# API stats
curl "https://book402.com/stats"

2. Pay for Deep Search¶

Paid endpoints use the x402 protocol. When you hit a paid endpoint without payment, you get a 402 Payment Required response with instructions:

curl -I "https://book402.com/search/hybrid?q=stoicism"
# HTTP/1.1 402 Payment Required
# PAYMENT-REQUIRED: eyJ4NDAyVmVyc2lvbi... (base64 payment requirements)

3. Set Up an x402 Client¶

TypeScriptPythonRust

npm install @x402/fetch @x402/evm viem

import { wrapFetchWithPayment, x402Client } from '@x402/fetch';
import { ExactEvmScheme, toClientEvmSigner } from '@x402/evm';
import { createWalletClient, createPublicClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { base } from 'viem/chains';

// Your wallet (NEVER hardcode in production!)
const account = privateKeyToAccount('0x...');
const transport = http('https://mainnet.base.org');

const publicClient = createPublicClient({ chain: base, transport });
const walletClient = createWalletClient({ account, chain: base, transport });
const signer = toClientEvmSigner(account, publicClient, walletClient);

// Create x402 client
const client = new x402Client();
client.register('eip155:8453', new ExactEvmScheme(signer));
const fetchWith402 = wrapFetchWithPayment(globalThis.fetch, client);

// Make a paid request — payment is automatic!
const res = await fetchWith402(
  'https://book402.com/search/hybrid?q=stoicism&limit=5'
);
const data = await res.json();
console.log(data);

pip install x402-python

# Coming soon — see x402.org for Python SDK

cargo add x402-reqwest

use x402_reqwest::X402ClientExt;

let client = reqwest::Client::new()
    .with_payments(signer)
    .prefer(USDCDeployment::by_network(Network::Base))
    .max(USDCDeployment::by_network(Network::Base).amount("1.00")?)
    .build();

let res = client
    .get("https://book402.com/search/hybrid?q=stoicism")
    .send()
    .await?;

4. What You Need¶

Requirement	Details
USDC on Base	Get USDC on Base L2 (Coinbase, Uniswap, bridge from Ethereum)
Wallet	Any EVM wallet with a private key (MetaMask export, or generate one)
ETH for gas	Tiny amount of ETH on Base for transaction fees (~$0.001)

Cost

A hybrid search costs $0.01 USDC (~10,000 units). That's 100 searches for $1.

Architecture Overview¶