The way you communicate with codecsCodex determines how helpful it will be.

A prompt is simply an instruction or question that tells Codex what you need, but a well-written prompt can mean the difference between vague and precise results.

Learning how to craft these prompts clearly and purposefully is one of the most important skills in using Codex effectively.

Codex doesn't run commands like a compiler. It predicts code based on patterns in your prompt. If your prompt is vague, Codex has to guess, and that often leads to incomplete, incorrect, or even unsafe code.

That's why clearer and more detailed prompts will generally give you better outputs.

Poor prompts are usually short, ambiguous, or missing key details. They don't specify language, constraints or expected behavior, so Codex makes assumptions.

Codex is at its most powerful when you provide it with clear, focused instructions and the right context.

Use these guidelines to craft effective prompts and get high quality results.

Be clear and specific. State exactly what you want Codex to do, rather than asking for vague improvements. Prompts like “refactor this function to reduce nesting” or “generate a π test test for the selected function” are much better than “fix this code”.

Provide relevant context and code pointers. Codex works best when it knows where to look. Mention specific files, functions, or code snippets, and supply grepable identifiers or stack traces if appropriate. Highlight or select the relevant lines in your editor before sending the prompt.

Define the desired outcome. Clarify whether you want an explanation, a refactor, new code, or a test. For example, “explain this function's purpose in plain English” versus “rewrite this code using list comprehensions”. Codex tailors its response to your stated goal.

Set constraints and boundaries. If you need Codex to work within certain limits, such as not changing public APIs, avoiding specific files, or following a particular style, mention this explicitly.

You can also customise how Codex approaches tasks, such as “use only standard library modules” or “follow our project's marketing template”.

Iterate and refine. Treat your interaction with Codex as a conversation. If the first response isn't quite right, follow up with clarifying questions or additional constraints. For example, “please simplify that loop further”. Or “can you provide a version with more comments?”

How to use Codex

About