x402++

x402 was the prototype.
x402++ is the product.

Programmable commerce protocol for AI agents. Built on Solana with TypeScript SDKs for Node.js. Instant settlement, cryptographic proof, autonomous negotiation.

3.5x

CHEAPER

vs x402

FASTER

settlement

50x

FEWER

blockchain txs

100%

AUTONOMOUS

no humans

NPM INSTALL

x402pp-client

TRY LIVE DEMO VIEW GITHUB

PROTOCOL FLOW

INTENT

Agent expresses needs

→

OFFER

Provider quotes price

→

SESSION

Prepaid channel opens

→

RECEIPT

Cryptographic proof

See the Difference

Watch x402++ outperform x402 in real-time

HOW IT WORKS

x402 (Original): Every single request requires a separate blockchain transaction. For 100 requests, that's 100 transactions at ~$0.025 each = $2.50 in fees alone, taking ~150 seconds.

x402++ (Enhanced): Create one session with prepaid funds, make 100+ requests off-chain with instant deduction, close session when done. Just 2 transactions at ~$0.00025 each = $0.0005 in fees, taking ~25 seconds.

Result: 3.5x cheaper, 6x faster, 50x fewer blockchain transactions. 100% accurate.

x402

ORIGINAL

Requests0/100

Blockchain Txs0

Total Cost$0.00

Status○ READY

ENHANCED

x402++

NEW

Requests0/100

Blockchain Txs0

Total Cost$0.0000

Status○ READY

AVAILABLE PACKAGES

Protocol foundation

x402pp-core

npm docs

For AI agents

x402pp-client

npm docs

For providers

x402pp-server

npm docs

Verification

x402pp-gateway

npm docs

Analytics

x402pp-indexer

npm docs

CODE EXAMPLES

import { X402Client } from 'x402pp-client';

const intent = client.createIntent({
  capability: 'gpt-4-inference',
  maxPricePerRequest: 0.01,
  token: 'USDC',
  sla: { maxLatencyMs: 2000 }
});

const offer = await client.negotiate(
  'https://api.provider.com',
  intent
);

// Returns:
// {
//   pricePerRequest: 0.008,  // 20% discount!
//   sla: { maxLatencyMs: 1500 },
//   signature: "..."  // Ed25519 signed
// }

const session = await client.createSession(offer, {
  depositAmount: 1.0  // 1 USDC
});

// Session created:
console.log(session.remainingBalance);  // 1.0 USDC
console.log(session.pricePerRequest);   // 0.008
// Can make 125 requests!

const result = await client.executeRequest(
  session.sessionId,
  { prompt: 'Explain quantum computing' }
);

console.log(result.data);     // AI response
console.log(result.receipt);  // Cryptographic proof

const receipt = result.receipt;

// Verify signature
verifyReceipt(receipt);  // Throws if invalid

// Check SLA
if (receipt.slaVerification.met) {
  console.log('✅ SLA met');
} else {
  console.log('❌ Breached');
  console.log('Refund:', receipt.slaVerification.refundAmount);
}

import { x402Middleware } from 'x402pp-server';

app.use('/api/*', x402Middleware({
  connection,
  wallet,
  endpoint: 'https://your-api.com',
  pricing: { basePrice: 0.01, token: 'USDC' },
  sla: { maxLatencyMs: 2000 }
}));

// All /api/* endpoints now monetized!

app.post('/api/inference', async (req, res) => {
  const result = await runInference(req.body);
  
  // Middleware auto-generates signed receipt
  return res.x402Receipt?.(result);
  
  // Receipt includes:
  // - Ed25519 signature
  // - SHA-256 hashes
  // - SLA verification
});

import { LoadBasedPricingStrategy } from 'x402pp-server';

const pricing = new LoadBasedPricingStrategy(
  0.01,     // base price
  'USDC',
  () => getCurrentLoad()  // returns 0-1
);

// Auto-adjusts:
// 0% load  → $0.01
// 50% load → $0.015
// 100% load → $0.02

// Anchor receipt to Solana
pub fn anchor_receipt(
    ctx: Context<AnchorReceipt>,
    receipt_id: String,
    session_id: String,
    input_hash: String,
    output_hash: String,
    sla_met: bool,
) -> Result<()> {
    let receipt = &mut ctx.accounts.receipt;
    receipt.receipt_id = receipt_id;
    receipt.session_id = session_id;
    receipt.sla_met = sla_met;
    Ok(())
}

// Get offers from multiple providers
const offers = await Promise.all(
  providers.map(p => client.negotiate(p, intent))
);

// Pick cheapest
const best = offers.sort(
  (a, b) => a.pricePerRequest - b.pricePerRequest
)[0];

// Agent auto-routes to best deal!