Pay with x402

npm install @x402/fetch @x402/core @x402/evm viem
# For Solana support, also install:
npm install @x402/svm @solana/kit @scure/base

pip install "x402[requests,evm]"
# For Solana support, also install:
pip install "x402[svm]" "solana<0.40"

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client, x402HTTPClient } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
// For Solana support, also import:
// import { ExactSvmScheme } from "@x402/svm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const signer = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const client = new x402Client();
client.register("eip155:*", new ExactEvmScheme(signer));
// Register a Solana signer too if you want the client to use Solana accept
// entries such as `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp`:
// client.register("solana:*", new ExactSvmScheme(svmSigner));
const fetchWithPayment = wrapFetchWithPayment(fetch, client);

const response = await fetchWithPayment("https://api.exa.ai/search", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    query: "best machine learning frameworks",
    numResults: 5,
  }),
});

const data = await response.json();
console.log(data.results);

// Check settlement receipt
const httpClient = new x402HTTPClient(client);
const receipt = httpClient.getPaymentSettleResponse(
  (name) => response.headers.get(name)
);
console.log("Transaction:", receipt?.transaction);

import os
import requests
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import wrapRequestsWithPayment
from x402.mechanisms.evm.exact import register_exact_evm_client
from x402.mechanisms.evm.signers import EthAccountSigner

account = Account.from_key(os.environ["WALLET_PRIVATE_KEY"])
client = x402ClientSync()
register_exact_evm_client(
    client,
    EthAccountSigner(account),
    networks="eip155:*",
)
session = wrapRequestsWithPayment(requests.Session(), client)

response = session.post("https://api.exa.ai/search", json={
    "query": "best machine learning frameworks",
    "numResults": 5,
})

data = response.json()
for result in data["results"]:
    print(result["url"], result["title"])
print("Payment response:", response.headers.get("PAYMENT-RESPONSE"))

# Step 1: Discovery, get pricing info
curl -s -o /dev/null -w "%{http_code}" -D - \
  -X POST "https://api.exa.ai/search" \
  -H "Content-Type: application/json" \
  -d '{"query": "best machine learning frameworks", "numResults": 5}'
# Returns 402 with PAYMENT-REQUIRED header containing base64-encoded pricing

# Step 2: Sign the payment with your wallet (use the SDK for this)
# Step 3: Retry with payment signature
curl -X POST "https://api.exa.ai/search" \
  -H "Content-Type: application/json" \
  -H "PAYMENT-SIGNATURE: <base64-encoded-payment>" \
  -d '{"query": "best machine learning frameworks", "numResults": 5}'
# Returns 200 with results + PAYMENT-RESPONSE header (settlement receipt)

const res = await fetch("https://api.exa.ai/search", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ query: "test query", numResults: 3 }),
});

// res.status === 402
const paymentRequired = JSON.parse(
  atob(res.headers.get("PAYMENT-REQUIRED")!)
);
console.log(
  paymentRequired.accepts.map(({ network, amount }) => ({
    network,
    amount,
  }))
);

import base64, json, requests

res = requests.post("https://api.exa.ai/search", json={
    "query": "test query",
    "numResults": 3,
})

# res.status_code == 402
pricing = json.loads(base64.b64decode(res.headers["PAYMENT-REQUIRED"]))
print([(accept["network"], accept["amount"]) for accept in pricing["accepts"]])

curl -s -D - -X POST "https://api.exa.ai/search" \
  -H "Content-Type: application/json" \
  -d '{"query": "test query", "numResults": 3}'
# Look for the PAYMENT-REQUIRED header in the 402 response
# Decode it: echo "<header-value>" | base64 -d