Ship It With Codex

You tried an AI coding agent. It made a mess, broke the build, and you went back to typing every line yourself. This is the book that fixes that.

Most AI coding books hand you prompt tricks and toy snippets. This one walks you through building and shipping one real full-stack SaaS, end to end, driven by the OpenAI Codex CLI agent loop. Not a demo. A real app you stand up, test, review, and merge to production.

What you will build

• Stand up a real Next.js and Postgres app from an empty repo
• Drive the entire build through the Codex CLI agent loop in the terminal
• Write the rules and sandbox limits that keep the agent in its lane instead of rewriting your repo
• Review, correct, and merge agent-written pull requests with confidence
• Run several agents in parallel to drain a backlog while you review the results
• Turn a flailing agent run into a clean, tested, shipped feature

Who this is for

The working developer who tried Cursor, Copilot, or a rival coding assistant, hit the wall, and bailed. If you want agentic coding that holds up under a real code review instead of vibe coding that falls apart, start here. No prior agent experience required, just the willingness to read a diff.

Why it is different

Every command, every file, every merge is real and runs. No hand-waving, no fake output. You learn AI pair programming the way it actually works on a shipping team: plan, generate, verify, ship.

Open the terminal, start the loop, and ship it.