Class: X402::Payments::Generator

Inherits:
Object
  • Object
show all
Defined in:
lib/x402/payments/generator.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = X402::Payments.configuration) ⇒ Generator

Returns a new instance of Generator.



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# File 'lib/x402/payments/generator.rb', line 14

def initialize(config = X402::Payments.configuration)
  @config = config
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/x402/payments/generator.rb', line 12

def config
  @config
end

Instance Method Details

#generate_header(amount:, resource:, description: nil, network: nil, private_key: nil, pay_to: nil, extra: nil) ⇒ Object 



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# File 'lib/x402/payments/generator.rb', line 18

def generate_header(amount:, resource:, description: nil, network: nil, private_key: nil, pay_to: nil, extra: nil)
  config.validate!

  chain_name = network || config.chain
  key = private_key || config.private_key
  recipient = pay_to || config.default_pay_to

  chain_config = X402::Payments.chain_config(chain_name)
  currency_config = X402::Payments.currency_config_for_chain(chain_name)

  # Convert amount to atomic units
  atomic_amount = convert_to_atomic(amount, currency_config[:decimals])

  # Get the Ethereum account from private key
   = Eth::Key.new(priv: key)
  sender_address = .address.to_s

  # Create nonce (32 random bytes)
  nonce = SecureRandom.random_bytes(32)

  # Build payment requirements
  payment_requirements = {
    scheme: "exact",
    network: chain_name,
    max_amount_required: atomic_amount.to_s,
    asset: chain_config[:usdc_address],
    pay_to: recipient,
    resource: resource,
    description: description || "Payment required for #{resource}",
    max_timeout_seconds: config.max_timeout_seconds,
    mime_type: "application/json",
    extra: extra || {
      name: currency_config[:name],
      version: currency_config[:version]
    }
  }

  # Prepare unsigned payment header
  valid_after = (Time.now.to_i - 60).to_s
  valid_before = (Time.now.to_i + config.max_timeout_seconds).to_s

  header = {
    x402Version: 1,
    scheme: "exact",
    network: chain_name,
    payload: {
      signature: nil,
      authorization: {
        from: sender_address,
        to: recipient,
        value: atomic_amount.to_s,
        validAfter: valid_after,
        validBefore: valid_before,
        nonce: "0x#{nonce.unpack1('H*')}"
      }
    }
  }

  # Sign the payment header
  signature = sign_payment(, header, payment_requirements, nonce)
  header[:payload][:signature] = signature

  # Encode to base64
  encode_payment(header)
end

#generate_link(amount:, resource:, description: nil, network: nil, private_key: nil, pay_to: nil, extra: nil) ⇒ Object 



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# File 'lib/x402/payments/generator.rb', line 84

def generate_link(amount:, resource:, description: nil, network: nil, private_key: nil, pay_to: nil, extra: nil)
  header = generate_header(
    amount: amount,
    resource: resource,
    description: description,
    network: network,
    private_key: private_key,
    pay_to: pay_to,
    extra: extra
  )

  {
    payment_header: header,
    curl_command: "curl -s -H \"X-PAYMENT: #{header}\" #{resource} | jq ."
  }
end