Handoff (Codex ↔ Claude Code)

Carry work progress between Codex and Claude Code through one shared, human-readable HANDOFF.md file at the project root. This skill only reads and writes that document — it never launches the other CLI.

This Codex instance writes tool: codex when it saves.

Modes

Read the argument passed with the invocation:

• save (aliases: out, 保存, 交接) → Save the current work into HANDOFF.md.
• resume (aliases: in, 接续, 恢复) → Resume from an existing HANDOFF.md.
• (no argument) → Auto-detect: if HANDOFF.md exists and its tool: header is not codex,

do resume; otherwise do save. State which mode you picked and why.

An explicit argument always wins over auto-detect.

The document lives at <cwd>/HANDOFF.md by default. If the user names a different path, use that.

Save

1. Reconstruct the work. From this session, identify: the goal, what was done, key decisions,

what works vs. what's still broken/partial, the concrete next steps, the relevant files, open questions, and how to verify.

1. Ground it in git (best-effort; skip cleanly if not a repo). Run:

• git rev-parse --abbrev-ref HEAD → branch
• git rev-parse --short HEAD → commit
• git status --short and git diff --stat → uncommitted changes for "Current state"

Use real output; never invent a branch/commit.

1. Write `HANDOFF.md` to the project root using the template below. Fill every section; if a

section truly has nothing, write - (none) rather than deleting the heading.

1. Confirm to the user: report the path written and the status, then print the pickup hint:

In Claude Code, cd into this directory and run /handoff resume (or /handoff to auto-detect).

Do not run claude yourself.

Resume

1. Read `HANDOFF.md` from the project root. If it is missing, tell the user there is nothing to

resume and stop (offer /handoff save instead).

1. Reality-check against git (best-effort): run git status --short and git rev-parse --short HEAD.

Compare the actual branch/commit/working tree to the document's header and "Current state". Explicitly flag any drift (e.g. doc says committed but the tree is dirty, or a different branch).

1. Summarize for the user, concisely:

• who handed off (tool / model / timestamp), the Goal, where it stands (status +

Current state), and the Next steps.

1. Continue from the first item under Next steps. Pause and confirm with the user before any

large or destructive action (consistent with this being a deliberate, controlled handoff).

HANDOFF.md template

Keep this format identical to the Claude Code side so either tool can read it.

---
tool: codex
model: <model name, e.g. gpt-5.5>
timestamp: <ISO 8601, e.g. 2026-06-02T14:30:00Z>
cwd: <absolute project path>
git_branch: <branch or "n/a">
git_commit: <short sha or "n/a">
status: in_progress | blocked | done
---

# Handoff: <one-line task title>

## Goal
<what we're ultimately trying to achieve>

## Done so far
- <completed work and key decisions, in order>

## Current state
<what works, what's broken/partial, files touched (paths)>

## Next steps
1. <ordered, concrete, actionable — the receiving tool starts here>

## Key files & references
- `path/to/file` — <why it matters>

## Open questions / gotchas
- <blockers, assumptions, things that bit us>

## How to verify / run
<commands to build/test/run and confirm state>