Session Handoff

session-handoff

session-handoff creates handoff documents and migrates active sessions between Claude Code and Codex.

The main product is the managed plugin bundle: skills, the MCP server, client launchers, and the internal migration engine. The npm package distributes that bundle and exposes the setup CLI. It is not a separate migration dependency.

Requirements

• Linux or macOS
• Node.js 18 or newer and npm
• Python 3.10 or newer
• Claude Code, Codex, or both, depending on which client you want to configure

Install

Use the managed setup command:

npx session-handoff@latest setup

The command installs a user-scoped plugin bundle, registers the MCP server, installs the client skill, and wraps each selected client launcher. Existing launchers are saved as *.session-handoff-original. Restart the client and any open shell after setup.

To configure one client only:

npx session-handoff@latest setup --client codex
npx session-handoff@latest setup --client claude

Use --yes for a non-interactive setup:

npx session-handoff@latest setup --client codex --yes

The client executable must already be on PATH. Without a client, setup stops with an error and changes nothing.

If a Codex update replaces the managed launcher while it is supervised, the supervisor restores it when Codex exits and keeps the updated executable as its target. Claude version updates are reconciled to the newest validated executable in its native versions directory. An installer run outside a supervised session cannot be repaired automatically; rerun setup afterward with --client codex or --client claude for the affected client.

Native plugin files

The repository and npm package include native Claude and Codex plugin manifests, the portable plugin manifest, the command, the skill, hooks, and the MCP configuration.

This repository is not itself a marketplace. The published wrapper is yuzushi-plugins.

Claude Code:

/plugin marketplace add yuzushi-dev/yuzushi-plugins
/plugin install session-handoff@yuzushi

Codex:

codex plugin marketplace add yuzushi-dev/yuzushi-plugins
codex plugin add session-handoff@yuzushi

The marketplace path installs the plugin source from GitHub. The npm path above distributes the published package and managed setup independently.

First use

After restarting the client:

Claude Code:

/session-handoff

Codex:

$session-handoff

Use migrate claude or migrate codex when you want to preserve the native session while changing clients. A normal handoff starts a clean session and keeps the implementation state in the handoff file.

Before Claude Code or Codex compacts a session, the plugin writes a small deterministic recovery checkpoint under ~/.local/state/session-handoff/checkpoints/. After SessionStart(source=compact) it injects only a pointer to that file. The checkpoint contains redacted Git state and a local lifecycle event log; it is recovery evidence, not a semantic summary, and manual $session-handoff remains the semantic handoff path. Lifecycle events record only hook names, IDs, paths, timestamps, and byte counts; they never contain prompts or tool payloads.

The checkpoint hook is fail-open: a write or Git-read failure does not block compaction. Do not treat its transcript path or Git output as secret-free project content; verify the live repository and transcript before acting.

Check the local setup without starting a model session:

npx session-handoff@latest doctor --pretty

Create mode writes handoffs under the workspace, usually in handoffs/. A clean repository does not need any project dependency or configuration file.

Remove the managed setup

npx session-handoff@latest uninstall --yes

This restores the saved client launchers and removes the managed bundle and registrations.

Telemetry

Telemetry is off by default. An interactive npm install asks once. Marketplace installs show a non-blocking reminder at session start. See [docs/telemetry.md](docs/telemetry.md) for the data inventory and controls.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: yuzushi-dev
• Source: yuzushi-dev/session-handoff
• License: MIT

Install and usage instructions live in the source repository linked above.