@t402/svm

Solana Virtual Machine (SVM) implementation for T402 payments using SPL tokens.

Installation

pnpm add @t402/svm

Overview

The @t402/svm package enables T402 payments on Solana using SPL token transfers. It supports:

USDC on Solana Mainnet and Devnet
Transaction simulation before settlement
Partial signing for fee payer abstraction

Network IDs

Network	CAIP-2 ID
Solana Mainnet	`solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp`
Solana Devnet	`solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1`

Client Usage

import { ExactSvmScheme } from '@t402/svm/exact/client'
 
// Create client scheme
const scheme = new ExactSvmScheme({
  address: 'YourPublicKey...',
  signTransactions: async (txs) => {
    // Sign transactions with your wallet
    return signedTransactions
  }
})
 
// Create payment payload
const payload = await scheme.createPaymentPayload(2, requirements)

Server Usage

import { ExactSvmScheme } from '@t402/svm/exact/server'
 
// Create server scheme for verification
const scheme = new ExactSvmScheme({
  rpcUrl: 'https://api.mainnet-beta.solana.com'
})
 
// Verify payment
const result = await scheme.verify(payload, requirements)

Facilitator Usage

import { ExactSvmScheme } from '@t402/svm/exact/facilitator'
 
// Create facilitator scheme
const scheme = new ExactSvmScheme({
  address: 'FacilitatorPublicKey...',
  signTransactions: async (txs) => signedTxs,
  getRpcForNetwork: (network) => rpc
})
 
// Verify and settle
const verifyResult = await scheme.verify(payload, requirements)
const settleResult = await scheme.settle(payload, requirements)

PaymentRequirements

const requirements = {
  scheme: 'exact',
  network: 'solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp',
  amount: '1000000', // 1 USDC (6 decimals)
  asset: 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v', // USDC mint
  payTo: 'RecipientPublicKey...',
  maxTimeoutSeconds: 300,
  extra: {
    feePayer: 'FeePayerPublicKey...' // Optional, defaults to payer
  }
}

Payment Flow

Client creates a SPL token transfer transaction
Client signs the transaction (partial signature)
Facilitator verifies the transaction structure
Facilitator adds fee payer signature and submits
Transaction confirms on Solana

Token Addresses

Token	Network	Mint Address
USDC	Mainnet	`EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v`
USDC	Devnet	`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`

⚠️

Solana requires the recipient to have an Associated Token Account (ATA) for the token. The facilitator will create the ATA if needed.

Error Codes

Code	Description
`invalid_payload_structure`	Missing or malformed transaction data
`network_mismatch`	Transaction network doesn’t match requirements
`unsupported_scheme`	Scheme not supported
`invalid_exact_svm_payload_missing_fee_payer`	Fee payer not specified
`invalid_exact_svm_payload_transaction`	Transaction parsing failed

Example: Full Integration

import { t402Client } from '@t402/fetch'
import { registerExactSvmScheme } from '@t402/svm/exact/client'
 
const client = new t402Client()
registerExactSvmScheme(client, {
  address: wallet.publicKey.toBase58(),
  signTransactions: wallet.signAllTransactions
})
 
const response = await client.fetch('https://api.example.com/premium')

@t402/evm @t402/ton