Class: Myrr::Pay::Middleware

Inherits:
Object
  • Object
show all
Defined in:
lib/myrr/pay/middleware.rb

Overview

Rack middleware that enforces payment on the sell-side.

Runs after identity middleware. For agent requests to paid endpoints, it checks the pricing from the Go server, then checks subscription or balance, debits if possible, or returns 402.

Examples:

In a Rails app

# config/application.rb
config.middleware.use Myrr::Pay::Middleware

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ Middleware

Returns a new instance of Middleware.

Parameters:

  • app (Object) —

    The Rack application

  • options (Hash) (defaults to: {}) —

    Optional overrides :client [Myrr::Pay::Client] Pre-configured pay client



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# File 'lib/myrr/pay/middleware.rb', line 20

def initialize(app, options = {})
  @app = app
  @client = options[:client]
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/myrr/pay/middleware.rb', line 25

def call(env)
  @env = env
  request = Rack::Request.new(env)

  # Skip for non-agent requests
  agent_did = env["myrr.agent_did"]
  unless agent_did
    return @app.call(env)
  end

  # Get pricing from Go server
  pricing = fetch_pricing
  unless pricing && pricing_requires_payment?(pricing)
    # Free endpoint — pass through
    return @app.call(env)
  end

  payg_cents = pricing.dig("payg", "per_1m_tokens_cents") || 0

  # Check subscription first
  sub = check_subscription(agent_did)
  if sub && sub["status"] == "active"
    tokens_remaining = (sub["tokens_included"] || 0) - (sub["tokens_used"] || 0)

    if tokens_remaining > 0
      # Serve content — billing happens after render
      status, headers, body = @app.call(env)

      content_type = headers["content-type"] || headers["Content-Type"] || ""
      if content_type.include?("text/markdown")
        body_text = ""
        body.each { |chunk| body_text << chunk.to_s }
        body.rewind if body.respond_to?(:rewind)

        token_count = count_tokens(body_text)
        if token_count <= tokens_remaining
          headers["X-Myrr-Billing"] = "subscription"
        end
      end

      return [status, headers, body]
    end
  end

  # Subscription exhausted or none — check PAYG balance
  status, headers, body = @app.call(env)

  content_type = headers["content-type"] || headers["Content-Type"] || ""
  unless content_type.include?("text/markdown")
    return [status, headers, body]
  end

  body_text = ""
  body.each { |chunk| body_text << chunk.to_s }
  body.rewind if body.respond_to?(:rewind)

  token_count = count_tokens(body_text)
  amount_cents = pay_cents(payg_cents, token_count)
  return [status, headers, body] if amount_cents <= 0

  # Check balance
  balance = check_balance(agent_did) || 0

  if balance >= amount_cents
    # Debit
    debit_agent!(agent_did, amount_cents, request.path_info, token_count)
    headers["X-Myrr-Billing"] = "payg"
    [status, headers, body]
  else
    # Return 402
    [402, { "content-type" => "application/json" }, [render_402(request, token_count, amount_cents, payg_cents)]]
  end
rescue => e
  warn "[myrr] Pay middleware error: #{e.message}"
  @app.call(env)
end