Codex CLI script builder — describe the automation, get the script

Paste into the Codex CLI:

'Write a [bash / Python / Node.js] script that does the following:

TASK: [DESCRIBE THE AUTOMATION IN PLAIN ENGLISH]

INPUTS: [What the script takes — files, directories, API keys, user arguments]
OUTPUTS: [What it produces — files, API calls, stdout, exit codes]
Environment: [OS, any dependencies already installed, credentials available as env vars]

The script must include:

1. ARGUMENT PARSING:
   - Named flags for every configurable option (e.g. --input, --output, --verbose)
   - A --help flag that prints usage
   - A --dry-run flag that logs what WOULD happen without making changes

2. INPUT VALIDATION:
   - Check that required arguments are provided before doing any work
   - Validate file paths exist before reading; validate directories before writing
   - Exit with a non-zero code and a clear error message on any validation failure

3. PROGRESS OUTPUT:
   - Print what the script is doing at each major step
   - For batch operations, show progress (e.g. "Processing 3/47: filename.csv")
   - In --verbose mode, print additional detail

4. ERROR HANDLING:
   - Catch errors from external calls (API, file I/O, subprocess)
   - On error: print the specific failure, clean up any partial output, exit with code 1
   - Never silently swallow an error

5. IDEMPOTENCY:
   - The script should be safe to run twice on the same input without corrupting output
   - Skip or overwrite (with a logged warning) rather than duplicating or crashing

Output only the script — no explanation, no markdown code block, just runnable code.'

Tip: start by describing the task in one messy sentence — Codex handles ambiguity better than most engineers expect; then refine by saying 'add a --filter flag that only processes files matching [pattern]' to iterate on the spec without rewriting from scratch.