ContextParcel

Stop re-explaining your project when switching AI agents.

One-click context handoff from ChatGPT to Codex, Claude Code, and Cursor. Discuss anywhere. Build anywhere.

简体中文 · Protocol · Security

ChatGPT / selected web text
             │
        click Handoff
             ▼
       ContextParcel
    conversation + Git
             │
       local handoff.md
        ┌────┼─────┐
        ▼    ▼     ▼
     Codex Claude Cursor

Your conversations stay on your machine. ContextParcel has no hosted backend, needs no account or API key, and never reads conversations you did not explicitly hand off.

First handoff

ContextParcel is currently distributed through GitHub Releases. The npm name is reserved but the package is not yet published to the npm registry.

npm install -g https://github.com/AIM135D/contextparcel/releases/download/v0.2.0/contextparcel-0.2.0.tgz

cd /path/to/your/project
contextparcel setup

setup registers the project, checks Git and the supported agent CLIs, starts the daemon in the background, and prints a pairing code. Running it again is safe.

Then install the browser extension:

1. Download contextparcel-extension-v0.2.0.zip from the v0.2.0 release and unzip it.
2. Open chrome://extensions or edge://extensions.
3. Enable Developer mode, choose Load unpacked, and select the unzipped directory.
4. Enter the one-time code printed by contextparcel setup (run contextparcel pair for a new one).
5. Open a ChatGPT conversation and click Handoff.

Preview sends only message counts, options, and the selected project ID to 127.0.0.1. Conversation text is transferred locally only after Send.

What moves—and what does not

Will include, when selected	Will not include
Chosen conversation messages and current task	Other conversations or hidden history
Branch, HEAD, changed file names, diff statistics, recent commits	.env, SSH keys, credentials, repository file contents, or full diff
Registered project identity and chosen target	Cloud upload, telemetry, or account data

Four focused capabilities

One-click handoff

Send selected messages, the most recent N messages, or the full open ChatGPT conversation. If ChatGPT changes its DOM, select text on any page and use Handoff selection from the browser context menu.

Project-aware

Each packet combines the authorized conversation with the registered repository's branch, HEAD, dirty state, changed file names, diff stat, and five recent commits. Git collection is read-only; full diffs and file contents are not collected.

Local-first

The extension talks only to a daemon bound to 127.0.0.1. A one-time pairing code establishes an extension-specific secret. The daemon validates both the exact extension Origin and the bearer token on every private route.

Open Handoff Protocol

Every transfer writes a versioned handoff.json plus a readable handoff.md. Third-party source and target adapters can implement the same Handoff Packet v1.

What gets created

contextparcel init registers the canonical project root and creates:

.contextparcel/
├── config.json
└── handoffs/
    └── .gitkeep

It adds this privacy rule to .gitignore:

.contextparcel/handoffs/*
!.contextparcel/handoffs/.gitkeep

Each handoff is stored under .contextparcel/handoffs/<id>/ as handoff.json and handoff.md. The global history index contains metadata only. Conversation artifacts remain locally until you run contextparcel delete <id> or contextparcel clear.

Browser workflow

The panel lets you choose:

• Target: Codex, Claude Code, or Cursor.
• Conversation: selected messages, recent messages, full conversation, or a generic page selection.
• Project: any root previously registered with contextparcel init.
• Included data: Git context, user messages, assistant messages, and the current task.

The extension does not type into ChatGPT, send ChatGPT messages, browse other conversations, or run arbitrary shell commands.

Positioning

ContextParcel handles the browser-to-local transition: an explicit subset of a web conversation becomes a reviewable local packet with repository state, then opens in an existing coding-agent CLI. It is not a chat archive, prompt manager, cloud sync service, or agent orchestrator.

CLI

contextparcel init [path]            initialize and register a project
contextparcel setup [path]           guided, idempotent first-time setup
contextparcel start                 start the daemon in the background
contextparcel stop                  stop the managed background daemon
contextparcel restart               restart the managed background daemon
contextparcel serve                 run the daemon in the foreground
contextparcel status                show daemon, pairing, and project state
contextparcel pair                  issue a one-time six-digit pairing code
contextparcel doctor                check Node, Git, daemon, extension, and agent CLIs
contextparcel history               list local metadata
contextparcel delete <id>           remove one packet and its conversation data
contextparcel clear                 remove every packet and history record
contextparcel send                  hand off text/JSON from a file, flag, or stdin
contextparcel demo                  print a sample handoff

Privacy-check a packet without launching an agent:

contextparcel send --target codex --message "Implement the agreed API" --dry-run

Send an exported array of { "role": "user|assistant", "text": "..." } messages:

contextparcel send --target claude --project my-project --file conversation.json

Target adapters

Target	Detection	Launch form	Install documentation
Codex	codex --version	codex --cd <project> <prompt>	Codex CLI
Claude Code	claude --version	claude <prompt>	Claude Code CLI
Cursor	agent --version, then cursor-agent --version	<command> <prompt>	Cursor CLI

ContextParcel uses the agent's existing login state. It does not read or copy authentication files. Agent processes are launched with an executable and argument array, never a shell-interpolated command.

Security model

The daemon accepts project IDs, not paths, from the extension. IDs resolve through the local project registry, and every generated artifact path is checked against the canonical registered root. Requests have strict Zod schemas and a 2 MiB body limit. CORS is granted only to the paired chrome-extension:// Origin.

ContextParcel does not read .env, SSH keys, credentials, repository file contents, or the full Git diff. See SECURITY.md for the threat model and reporting process.

Develop from source

Requires Node.js 20 or later.

git clone https://github.com/AIM135D/contextparcel.git
cd contextparcel
npm ci
npm run verify
node dist/contextparcel.cjs demo

Load apps/extension/dist as an unpacked extension after npm run build.

Demo

Run contextparcel demo for an installation-free example, or inspect examples/sample-handoff. docs/demo-script.md contains a 10–20 second recording plan. The repository does not include a simulated browser recording presented as a real one.

Related projects

• ContextRelay coordinates context between coding agents. ContextParcel concentrates on the preceding transition from a web planning conversation into a local coding agent, with repository state attached.
• HandoffKit explores structured handoffs for AI coding work. ContextParcel adds an explicit browser-to-local flow and a paired localhost boundary.

These tools address adjacent workflows; the distinctions above describe scope, not quality.

V0.2 limitations

• ChatGPT Web is the only structured web adapter. Other sites use text selection.
• The extension is distributed as a release ZIP, not through Chrome Web Store or Edge Add-ons.
• npm registry publication needs maintainer authentication; install the release tarball instead.
• Packets are local files with no cloud sync, team workspace, or automatic summarization.

Contributions are welcome. Start with CONTRIBUTING.md, especially the small source and target adapter interfaces.

MIT © 2026 ContextParcel contributors