Environment and Tools (Codex CLI) - Shell usage - Prefer `rg` for search and `sed -n` with 250‑line chunks. - Print concise preambles before tool calls; group related actions. - Use `apply_patch` for file edits; avoid unrelated changes. - Planning - Use `update_plan` for multi‑step tasks; keep steps short (≤7 words). - Exactly one step `in_progress` until done; mark completion as you go. - Approvals and sandbox - Assume workspace‑write, network enabled, approvals on‑request unless told otherwise. - Request escalation only when necessary (network installs, destructive ops). - Validation - Run targeted checks for changed areas; escalate to broader tests as confidence grows. - Don’t add formatters or miscellaneous tooling unless requested.