What is x402 API payment?

x402 is a payment protocol for Solana that enables pay-per-use API monetization. Your API returns HTTP 402 Payment Required with payment details. AI agents using ParasolDEX automatically handle the payment, swap tokens if needed, and retry the request.

How do I accept x402 payments for my API?

Return HTTP 402 Payment Required with payment details (amount, token, recipient address) when payment is required. Agents using ParasolDEX will automatically handle payment, swap tokens if needed, and retry. No additional integration needed on your side.

What tokens can I accept with x402?

You can accept any SPL token on Solana including SOL, USDC, USDT, or any custom token. ParasolDEX automatically handles token swapping, so agents can pay with any token even if you specify a different one.

for API providers

get paid per request. automatically.

Return a 402. Get paid in USDC, SOL, or any token. Agents using ParasolDEX handle everything — token swaps, payment, retry. You just serve the data.

Implementation guide Learn about x402

how it works

agent calls your API

standard HTTP request for data or a service.

you return 402 Payment Required

with amount, token, and your Solana wallet address.

agent pays automatically

ParasolDEX swaps tokens if needed and sends payment on-chain.

agent retries with proof

includes payment signature in X-Payment header.

you serve the request

verify the signature, return the data. done.

implementation

step 1: return 402 response

// your API endpoint
app.get('/api/data', (req, res) => {
  if (!hasPayment(req)) {
    return res.status(402).json({
      accepts: [{
        network: 'solana',
        asset: 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v', // USDC
        amount: '1000000', // 1 USDC (6 decimals)
        address: 'YOUR_SOLANA_WALLET_ADDRESS'
      }]
    });
  }

  // payment verified, return data
  res.json({ data: '...' });
});

step 2: verify payment

function verifyPayment(req) {
  const signature = req.headers['x-payment'];
  if (!signature) return false;

  // verify on Solana: check amount, token, recipient
  const tx = await connection.getTransaction(signature);
  return isValidPayment(tx, expectedAmount, expectedToken);
}

why x402

higher conversion

agents pay automatically with zero friction. no checkout pages, no payment forms, no drop-off.

instant settlement

payments settle on-chain instantly. no waiting periods, no chargebacks, no manual processing.

accept any token

agents auto-swap to your required token via ParasolDEX. accept USDC, SOL, or any SPL token.

global, 24/7

accept payments from anywhere, anytime. Solana operates without borders or banking hours.

transparent

all payments are on-chain, verifiable, and immutable. no chargebacks, no disputes.

scalable revenue

charge per-request, per-call, or per-operation. revenue scales linearly with usage.

x402 vs traditional billing

	subscription	Stripe metered	x402
settlement	30 days	2-7 days	instant
chargebacks	yes	yes	impossible
agent-compatible	no	partial	native
global access	bank required	bank required	wallet only
minimum payment	$0.50+	$0.50+	$0.0001
setup time	weeks	days	minutes

faq

what tokens can I accept?

any SPL token on Solana — SOL, USDC, USDT, or custom tokens. agents auto-swap to your required token, so you always get what you asked for.

how do I get paid?

payments go directly to your Solana wallet on-chain. instant, no intermediaries, no waiting periods.

what if an agent doesn't pay?

the 402 response persists and the agent can't access your API. you only serve data when payment is verified.

is there a minimum payment?

no minimum enforced by ParasolDEX. Solana network fees are ~$0.00025 per transaction, so micropayments are practical.

can I track payments?

all payments are on-chain Solana transactions. use any explorer or build your own analytics. every payment is transparent and verifiable.

integrate x402 payments into your API. get started in minutes.

Read the docs x402 vs subscriptions

how it works

agent calls your API

standard HTTP request for data or a service.

you return 402 Payment Required

with amount, token, and your Solana wallet address.

agent pays automatically

ParasolDEX swaps tokens if needed and sends payment on-chain.

agent retries with proof

includes payment signature in X-Payment header.

you serve the request

verify the signature, return the data. done.

implementation

step 1: return 402 response

// your API endpoint
app.get('/api/data', (req, res) => {
  if (!hasPayment(req)) {
    return res.status(402).json({
      accepts: [{
        network: 'solana',
        asset: 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v', // USDC
        amount: '1000000', // 1 USDC (6 decimals)
        address: 'YOUR_SOLANA_WALLET_ADDRESS'
      }]
    });
  }

  // payment verified, return data
  res.json({ data: '...' });
});

step 2: verify payment

function verifyPayment(req) {
  const signature = req.headers['x-payment'];
  if (!signature) return false;

  // verify on Solana: check amount, token, recipient
  const tx = await connection.getTransaction(signature);
  return isValidPayment(tx, expectedAmount, expectedToken);
}

why x402

higher conversion

agents pay automatically with zero friction. no checkout pages, no payment forms, no drop-off.

instant settlement

payments settle on-chain instantly. no waiting periods, no chargebacks, no manual processing.

accept any token

agents auto-swap to your required token via ParasolDEX. accept USDC, SOL, or any SPL token.

global, 24/7

accept payments from anywhere, anytime. Solana operates without borders or banking hours.

transparent

all payments are on-chain, verifiable, and immutable. no chargebacks, no disputes.

scalable revenue

charge per-request, per-call, or per-operation. revenue scales linearly with usage.

subscription

Stripe metered

x402

settlement

30 days

2-7 days

instant

chargebacks

yes

impossible

agent-compatible

partial

native

global access

bank required

wallet only

minimum payment

$0.50+

$0.0001

setup time

weeks

days

minutes

faq