Skip to main content
A port forward makes a localhost port on one of your machines reachable as a localhost port on another. Agents use it when a process on one machine, such as a dev server, has to be reached from another machine, such as the one running your browser or the in-app browser. Traffic travels over the connection your hosts already hold. Both ends are loopback only, so nothing is opened to your network.

​
How A Forward Starts

Agents create forwards with the Forward Port tool. You can’t start one from the app yourself; ask the agent, for example “forward the dev server to my laptop”.
  • One end is always the agent’s own host. The other is another host on your account.
  • The listening machine tries the same port number first, so localhost:5173 stays localhost:5173 and OAuth redirects, CORS allowlists and browser storage keep working. If that port is taken, another port is used and the agent is told which.
  • Only unprivileged ports (1024–65535) can be forwarded, and Traycer’s own ports can’t be.
  • Each consumer of a server gets its own forward.
Only agents on the Chat interface have the forwarding tools. See Terminal agents vs terminals.

​
When A Forward Ends

A forward lasts until one of these happens:
  • You or the agent stops it.
  • The agent is stopped.
  • Either host restarts.
  • Someone cuts it on the other machine (see Ports on the Other Machine).
A forward that ends without being stopped becomes Interrupted, and the agent is told once. It doesn’t come back on its own; ask the agent to forward the port again. An agent with an open forward can’t be archived until the forward is stopped.

​
In The Chat

An agent’s forwards appear in its Background panel, above the composer. Each row shows the forward’s description, its port, and its state:
  • Open localhost:<port> in the browser appears when the listening end is this computer.
  • Stop closes the forward and its open connections.
  • On an interrupted forward, Clear removes the record.
Expand a row to see why it is in its state and what happened to it recently. Stop all in the Background panel doesn’t stop forwards; each has its own Stop.

​
In Settings

Settings › Host › Overview › Ports lists the forwards on the host chosen in the host picker. See Overview.

​
Forwards on This Host

Forwards that this host’s agents created. Each row shows the description, the port, the route (for example laptop:5173 → build-box:5173), open connections and bytes in and out.

​
Ports on the Other Machine

Ports other machines hold here lists ports that forwards from other machines use on this host. A row reads Listening for <machine> when the port is open on this host and carries traffic to that machine, or Reached by <machine> when that machine reaches this port through a forward. Cut closes the port here and its open connections. It asks “Cut port <port>?” first. The forward on the other machine becomes Interrupted and its agent is told. The lists refresh every 15 seconds while the page is open; Refresh reads them again now. When anything is forwarded or held, the Ports tab shows a count. If nothing is, the tab reads “Nothing is forwarded through <host>.”