Real‑time collaboration in Atom with Teletype: start a portal and edit together

Problem

When two developers need to tweak the same file at the same time, sharing a repository and constantly pulling/pushing can interrupt the flow. A lightweight way to see each other's cursors and edits instantly, without setting up a shared repo, keeps the workflow smooth.

How Teletype works in Atom

Teletype is a bundled package that uses WebRTC for peer‑to‑peer data exchange after an initial handshake through GitHub’s signaling server. When you start a portal, Atom creates a random identifier and shows a URL like https://teletype.atom.io/xxxxxxxx. Anyone with Atom 1.22+ can open that URL, join the portal, and see each other's cursor positions and edits as they happen. All changes are applied to each client’s local buffer, so when the portal ends the file remains edited on each machine.

Worked example: starting a portal and collaborating

1. Open Atom (version 1.22 or newer). Ensure the teletype package is enabled via Settings → Packages.
2. Click the Teletype icon in the status bar (two overlapping circles) and choose Start a portal.
3. Copy the generated URL from the dialog.
4. In a second Atom instance (on another machine or the same machine), paste the URL into the Teletype join prompt (Join a portal) and press Enter.
5. Both editors now show the same file. Type a line in one pane; the text appears instantly in the other, and the remote cursor moves with your typing.
6. When finished, click the Teletype icon and select Close portal. The session ends, but each local buffer retains the edits made during the session.

Limitations and verification steps

• The signaling server is public; if it is blocked by a firewall or unreachable, new portals cannot be started.
• Edits are merged via operational transformation. Simultaneous changes to the same line create a conflict that must be resolved manually.
• To verify that Teletype is working:
  • Open Settings → Packages and confirm teletype is listed and enabled.
  • Start a portal, copy the URL, join it in another Atom window.
  • Type a short string (e.g., # test) in one editor and watch it appear in the other.
  • Close the portal and check that the string remains in both local buffers.

Actionable closing

If you need a quick, repository‑free way to pair‑program or review code, enable Teletype, start a portal, and share the URL. Remember the dependency on the GitHub signaling server and be ready to resolve line‑level conflicts manually. With those caveats in mind, Teletype can turn an ad‑hoc editing session into a smooth, real‑time collaboration.