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Codex / Codex CLI Complete Guide

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This hub is for readers choosing where to start with Codex CLI, approvals, automation, and GPT-5-Codex. Follow the tabs by level to move from setup to safer automation without jumping into advanced patterns too early.

An AI agent deeply integrated with engineering workflows: command execution, review automation, and parallel tasking.
Pick a tab for your level and follow the steps.

What we learned from daily use

Codex CLI operations center on approvals, permissions, and logs/reproducibility. The Plan mode "think then execute" workflow is the most stable pattern.


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Step 1 — Install and basics

Step 2 — Learn best practices

📝 Beginner advice: Start with Quickstart → Best Practices. The Pricing Guide can wait until you consider paid plans.

Safely automate with approval policies, Plan mode, and CI integration.

Step 3 — Understand approvals and Plan mode

Step 4 — Build automation pipelines

💡 Practitioner's tip: Go "Plan mode → Approval policy → CI integration" in order. Learning Plan mode first naturally reveals why approval design matters.

Achieve 7-hour autonomous operation with GPT-5-Codex architecture.

Step 5 — Master GPT-5-Codex

Version updates

💡 For advanced users: GPT-5-Codex autonomous runs are powerful, but approval policy and Plan mode design are prerequisites. Skipping intermediate steps leads to accidents.


Troubleshooting

ArticleDescription
Network Restrictions FixCommon network issue solutions
Diagnostic Logs Deep DiveTroubleshooting practice guide
5 Production Failure PatternsQuick fixes for common failures
Context Window ErrorFix "ran out of room" instantly

Comparison & Selection

ArticleDescription
Codex CLI vs Claude CodeHow to choose in practice
2026 Benchmark ComparisonAccuracy vs speed — which to pick