Guide · codex cli guide
Codex CLI guide for real codebase work
A practical Codex CLI workflow for reading a repo, changing code, checking tests and keeping changes small.
Quick answer
A good Codex CLI workflow is simple: read project instructions, inspect the code path, make the smallest useful change, run the local checks and summarize what changed with file references.
The operating loop
Start with fast repo search, then read the closest files before editing. After each change, run the narrowest check that proves the behavior and only widen the test scope when the risk is real.
What makes it reliable
Reliability comes from bounded edits, explicit assumptions, non-destructive git behavior, and refusing to hide failing migrations, tests or security checks.
FAQ
Should Codex edit before reading the codebase?
No. The agent should inspect local patterns first, then make changes that fit the existing architecture.
What is the best first check after a code edit?
Run the narrowest relevant check first: a unit test, type-check, pSEO check or lint command depending on what changed.