Ax is a local tool that enables Claude, Codex, and OpenCode to communicate with each other. The example demonstrates building a signup feature through coordinated message exchanges between components to define fields, validation rules, and error handling.
StopReg is an email validation API that detects disposable and fraudulent email addresses to prevent signup abuse. It offers real-time validation through two endpoints (full email or domain-only), checks for disposable emails, role-based addresses, public providers, and MX records, with tiered pricing plans from 60,000 to 2.8 million monthly requests.