git:20260918.4729d23 to git:20260920.6de3dc1

- # Codex Skill Guide

-

- ## Running a Task

-

- 1. If unclear, ask the user (via AskUserQuestion) what they want reviewed or changed.

- 2. Assemble the codex command with appropriate options:

- - `-m, --model gpt-5.6-sol` (default model; pair with `-c model_reasoning_effort="xhigh"`. Fallback if unavailable: `gpt-5.6-terra`, also at xhigh)

- - `-c model_reasoning_effort="xhigh"` (default reasoning effort; options: `none`, `minimal`, `low`, `medium`, `high`, `xhigh`)

- - `--sandbox <mode>` - use `read-only` for reviews, `workspace-write` for edits, `danger-full-access` for network/broad access

- - `--full-auto` - only for write operations, not needed for read-only

- - `-C, --cd <DIR>` - run from a different directory

- 3. When continuing a previous session, use resume syntax:

- ```

- codex exec resume --last "your prompt here" </dev/null 2>/dev/null

- ```

- Add `--skip-git-repo-check` if running outside a git repo.

- Do not use configuration flags when resuming unless explicitly requested - the session inherits original settings.

- 4. For code reviews, prefer the dedicated review subcommand:

- ```

- codex exec review --base main </dev/null 2>/dev/null

- ```

- Options: `--uncommitted` (staged/unstaged/untracked), `--base <branch>`, `--commit <sha>`.

- **The scope flags cannot be combined with custom review instructions.** Each of

- `--base`, `--commit`, and `--uncommitted` conflicts with the `[PROMPT]` positional

- and fails arg parsing (`the argument '--base <BRANCH>' cannot be used with

- '[PROMPT]'`, verified on codex-cli 0.146.1). So pick one:

- - Codex's default review instructions on a specific scope: use `codex exec review`

- with the scope flag and no prompt, as above.

- - Your own review instructions: use plain `codex exec` and state the scope in the

- prompt, e.g. `codex exec --sandbox read-only "<instructions>. Review only the

- changes on this branch relative to main; see them with git diff main...HEAD."`

- 5. **IMPORTANT**: Append `2>/dev/null` to suppress thinking tokens (stderr). Only show stderr if debugging is needed.

- 6. **Always redirect stdin from `/dev/null`.** `codex exec` appends stdin to the

- prompt, so without the redirect it blocks on an open terminal and looks exactly

- like a slow reasoning pass, hanging until killed. The tell is empty stdout with

- `Reading additional input from stdin...` on stderr.

- 7. Run the command, summarize the outcome for the user.

- 8. **After Codex completes**, inform the user: "You can resume this Codex session at any time by saying 'codex resume'."

- ## Quick Reference

- | Use case | Command example |

- | Code review | `codex exec review --base main </dev/null 2>/dev/null` |

- | Review uncommitted | `codex exec review --uncommitted </dev/null 2>/dev/null` |

- | Review a commit | `codex exec review --commit abc123 </dev/null 2>/dev/null` |

- | Apply edits | `codex exec --sandbox workspace-write --full-auto "Refactor..." </dev/null 2>/dev/null` |

- | Full access | `codex exec --sandbox danger-full-access --full-auto "..." </dev/null 2>/dev/null` |

- | Resume | `codex exec resume --last "continue with..." </dev/null 2>/dev/null` |

- | Different dir | `codex exec -C /path/to/dir --sandbox read-only "..." </dev/null 2>/dev/null` |

-

- ## Following Up

-

- - When output includes actionable findings or the user might want changes applied, offer to resume the session.

- - When resuming, pass the new prompt as an argument - the session keeps its original model, reasoning effort, and sandbox mode.

-

- ## Auto-Fixing Critical Bugs in PR Reviews

-

- When codex identifies **HIGH severity** bugs during PR reviews, automatically fix them without asking for permission:

-

- 1. **Identify severity**: Parse codex output for "High" or "HIGH" severity bugs

- 2. **Auto-fix workflow**:

- ```bash

- # Resume codex session with fix instructions

- codex exec resume --last --sandbox workspace-write --full-auto "Fix all HIGH severity bugs identified in the review. For each bug, apply the necessary code changes." </dev/null 2>/dev/null

- ```

- 3. **Commit fixes**: After codex applies fixes, commit with descriptive message

- 4. **Report**: Tell user what was fixed

-

- **Severity guidelines:**

- - **HIGH**: Auto-fix (data loss, security holes, correctness bugs, broken functionality)

- - **MEDIUM**: Ask user first (performance issues, tech debt, unclear impact)

- - **LOW**: Report only (style suggestions, minor improvements)

-

- **Safety notes:**

- - Only auto-fix in review/PR context (not exploratory coding)

- - Always commit fixes immediately after applying

- - User can revert commits if needed

- - If codex fix fails or is unclear, stop and ask user

-

- **Example:**

- ```

- Codex found: "High - Date constraints never reach Qdrant"

- → Automatically resume codex to fix

- → Commit: "Fix: Push date constraints to Qdrant query"

- → Report: "Fixed HIGH severity date filtering bug in query.py"

- ```

- ## Error Handling

- - Stop and report failures when `codex` exits non-zero; request direction before retrying.

- - Before using `--full-auto`, `--sandbox danger-full-access`, or `--skip-git-repo-check`, ask for user permission unless already given.

- - When output includes warnings or partial results, summarize and ask how to proceed.