// Track

Getting Started with OpenAI Codex

Ship Code with OpenAI's Agent

From zero to shipping with OpenAI Codex — the agent that reads your repo, edits files, and runs commands. Install the CLI, learn the agent loop, wire up the Responses API, and ship a real feature with approvals and AGENTS.md keeping you in control. The API lessons near the end use short TypeScript examples, so basic JavaScript/TypeScript familiarity helps (a Python path is signposted).

12 lessons~105 min total

Lessons are shown in recommended order. Complete them in sequence for the best experience — or jump to any lesson.

Lesson 524·7 min read

What Is OpenAI Codex?

OpenAI Codex is an agentic coding tool that reads your repository, edits files, and runs commands — a new category beyond autocomplete or chat.

Lesson 525·8 min read

Your OpenAI Account, API Keys, and Auth

Two paths into OpenAI — subscription sign-in or API key. Know which surface uses which, how to store credentials safely, and how to never leak a key.

Lesson 526·9 min read

Installing and Running the Codex CLI

From zero to running your first agentic coding session: install the Codex CLI, authenticate, and understand the interactive session lifecycle.

Lesson 527·8 min read

The Codex Loop: How the Agent Thinks

OpenAI Codex is not a smarter autocomplete — it is an autonomous agent that loops through perceive, reason, act, and observe until the task is done.

Lesson 528·9 min read

The Models Behind Codex

The model you pick and the reasoning effort you set determine cost, latency, and quality — here is how to read the tradeoffs and route tasks to the right tier.

Lesson 529·9 min read

Prompting Codex and the AGENTS.md File

Tight task prompts and a well-maintained AGENTS.md are the two cheapest investments that produce the biggest reliability gains in Codex-powered workflows.

Lesson 530·9 min read

Approvals, Sandboxing, and Safety

Codex autonomy is set by two independent dials — an approval policy and a sandbox mode — learn the blast-radius mental model that lets you choose the right combination.

Lesson 531·8 min read

The Responses API: Your First Direct Call

Drop below the Codex agent to the raw OpenAI API — learn when to call it directly and how to make your first Responses API request.

Lesson 532·10 min read

Tool Calling and Structured Output

Connect models to real data with tool calling, and lock response shapes with structured output — the two primitives that turn a chatbot into a production API.

Lesson 533·9 min read

MCP: Extending Codex with Your Own Tools

MCP is the open standard that turns Codex from a code generator into an agent that can read your database, query your APIs, and remember context across sessions.

Lesson 534·9 min read

Codex in the Cloud and Integrations

Delegate a task to Codex cloud, walk away, and come back to a pull request — this lesson teaches you to use Codex as an async contributor, not just a session-bound tool.

Lesson 535·10 min read

Capstone: Ship a Feature with Codex

Scope it, write the AGENTS.md, run the session, review the diff, test, PR, verify — this lesson walks the full pipeline end-to-end and defines what done actually means.