Codex

$5,000 in AI Credits: A System Inventory In one month, spending roughly $5,000 on AI subscriptions and APIs (Claude Pro + Claude API + OpenAI API + Copilot Pro+ + Codex + Paseo + miscellaneous), I built out 18 major systems independently, with a total codebase of roughly 50,000+ lines of code (excluding auto-generated AI scripts). For comparison: the same functionality, developed from scratch by 2 full-stack engineers, would conservatively take 6-12 months and cost at least ¥300,000-600,000. ...

OpenAI released Codex CLI in early 2025—a tool that lets you write code, edit files, and run commands directly in your terminal using AI. Unlike ChatGPT on the web, Codex CLI’s core strength is directly manipulating your local filesystem, so AI actually gets work done instead of just handing you snippets to paste. This guide covers the complete setup from installation to your first task, taking about 10 minutes. ...