copifi

Shared clipboard for devices on the same WiFi. A host starts a named room and gets a join code. Other devices discover rooms on the network and join with that code. Once joined, copying anything on any device shows up on all the others — automatically, in the background. Fully local: nothing leaves your network.

Runs over self-signed HTTPS so browsers allow clipboard access on other devices.

Install

Needs Node.js 18+ on every device that runs the CLI.

npm install -g copifi

That gives you the global copifi command. Verify with copifi help.

Certificates are stored in ~/.copifi/certs (a user-writable location), so the global install works without permission issues.

Run from source instead

git clone https://github.com/entrepreter/copifi.git
cd copifi
npm install
npm link          # global `copifi` command — or just use `node cli.js <command>`

For maintainers — releasing updates

The package is published to npm as copifi and the source lives at github.com/entrepreter/copifi. To ship an update:

npm version patch            # bump the version (patch | minor | major)
git push --follow-tags
npm publish

Tip: npm pack --dry-run previews exactly which files get published.

The flow

1. On the host machine — start a room:

copifi host office

This prints the room's join code (e.g. 4821), a QR code, and starts syncing the host's own clipboard. Leave it running.

2. On another machine — see what's on the network:

copifi ls

ROOM     HOST                 ADDRESS
office   shivam-pc.local      192.168.1.42:3000

3. Join by name and enter the code:

copifi join office
Enter the room code: 4821

That's it. Copy anything on any joined device and it lands on every other device in the room.

Phones (or anyone without the CLI) can join from a browser: open https://<host-ip>:3000, type the code, and go.

Commands

| Command | What it does | | --- | --- | | copifi host <name> | Start the room's server and sync this device. Prints the join code. | | copifi serve <name> | Start only the server (a hub; doesn't sync this device's clipboard). | | copifi ls | List rooms available on this WiFi. | | copifi join <name> | Find the room on the network and join it (prompts for the code). | | copifi help | Show help. |

Flags: --code <code> (skip the prompt), --name <name> (device label), --port <n>, --poll <ms>, --server <url> (join a URL directly, skipping discovery).

Levels of "automatic"

• CLI / native (host, join) — true background sync. Copy anywhere, in any app, no window needed. This is the recommended way on laptops/desktops.
• Browser — auto-syncs while the copifi tab is in front (the browser asks for clipboard permission once). A browser tab cannot read the clipboard while it's in the background — that's a security rule in every browser and OS, which is exactly why the native CLI helper exists.

Phones & an "Apple Universal Clipboard"-like experience

Apple's Universal Clipboard feels magical because it's built into the OS — the system watches the clipboard in the background and syncs via Handoff. Third-party apps cannot get that same background access on phones, so here's what's actually achievable per platform:

• Desktops (Windows / macOS / Linux): already Apple-like. The CLI helper (host / join) reads and writes the OS clipboard in the background — copy anywhere, it appears everywhere. No window needed.
• Android: a native app can approximate it by running a foreground service (with a persistent notification) to watch the clipboard. Android 10+ restricts background clipboard reads, so the notification/foreground-service is required — close but not invisible.
• iOS: Apple does not allow any third-party app to read the clipboard in the background; only the system's own Universal Clipboard can. The realistic iOS experience is: a Share-sheet extension ("Share → copifi") to push, and open/tap to paste. Not fully automatic — that's an Apple platform limit, not a design choice.

Today, with zero install, a phone joins via the browser: scan the QR the host prints (or open https://<host-ip>:3000), enter the code, and it's in the room — receiving clips and sending with Send/auto-send. The limit is that a phone browser only reads the clipboard while the tab is in the foreground.

Recommended path to get as close as possible:

1. Use the CLI on all laptops/desktops — that half is already seamless.
2. For phones, use the browser client (optionally as a PWA "add to home screen"). Accept foreground-only clipboard.
3. Only if you truly need hands-free phone sync, build a thin native app (React Native/Flutter) that talks to the same room server: a foreground service on Android, and a Share extension + in-app paste on iOS. The server/protocol here is already the backbone for that — no server changes needed, just native clients.

Cross-platform

Works on Windows, macOS, and Linux — same commands everywhere.

• Clipboard access needs no extra setup on Windows or macOS (built-in tools). On Linux, install xsel or xclip.
• First run of host/serve may trigger a firewall prompt (Windows Defender / macOS) — allow it on private networks so other devices can connect, and so mDNS discovery works.
• Discovery uses mDNS/Bonjour. If ls shows nothing (some corporate/guest networks block multicast), join directly: copifi join <name> --server https://<host-ip>:3000.

The certificate warning (expected)

The cert is self-signed, so a browser shows a one-time warning on first connect — click Advanced → Proceed. The CLI accepts the LAN cert automatically. Want warning-free certs? Install mkcert, run mkcert -install and mkcert <host-ip>, then drop key.pem/cert.pem into ./certs.

How it works

• Transport: WiFi/LAN only; the server binds 0.0.0.0.
• Discovery: each host advertises _clipshare._tcp via mDNS; ls browses for it (discovery.js).
• Auth: the room code is the shared secret — correct code = admitted (no manual approval).
• Realtime: a single WebSocket hub relays clips to all authenticated members. State is in memory.
• Clipboard: the native helper reads/writes the OS clipboard in the background; the browser uses navigator.clipboard when focused. Echo protection stops received text from bouncing back.

Files

• cli.js — the copifi command (host / serve / ls / join).
• server.js — HTTPS + WebSocket hub for one named, code-authenticated room; mDNS advertising.
• helper.js — background OS-clipboard sync client.
• discovery.js — mDNS publish/browse.
• public/index.html — the browser client.