Reticle Docs: verification for AI coding agents

reticle open is the one-command “show me the app”. It resolves the port, makes sure a daemon is up, and then either reuses the tab that is already connected or hands the URL to your operating system’s default browser. It never opens the browser Reticle drives.

npx @reticlehq/server open [url] [--port N] [--navigate]

Arguments and flags

Argument	Type	Default	What it does
`url`	string, positional, optional	unset	The URL to open. Omit it to reuse a connected tab
`--port N`	number	`4400` (or `RETICLE_PORT`, or the port in `.reticle.json`)	Bridge port. If nothing is on it, `open` discovers a running daemon rather than making you hunt
`--navigate`	flag	off	When a tab of this project on the url’s origin is connected but on another page, move that tab to the url and wait for it to arrive. Exits `1` when the move fails. Without it the tab is left where it is

It is idempotent. Re-running never piles up duplicate tabs.

What it prints

One reticle_open line, whose fields say which of these happened.

Fields	Meaning
`reusing`	A connected tab was already on the right page. Nothing was opened
`reusing` + `requested` + `note`	A tab is connected on that origin but sitting on a different page. It was left there, not navigated. Drive it with `reticle_navigate` or open the URL yourself
`navigated` + `sessionId` (+ `landedOn`)	With `--navigate`: that tab was moved to the url and arrived. `sessionId` is the session it reconnected as, and `landedOn` names a redirect when the page ended somewhere else
`requested` + `note` (with `--navigate`)	The browser accepted the navigation but no page on the url reconnected in the wait window, so arrival was not observed
`opened` + `connected: true`	The URL went to the system default browser and a new Reticle session appeared within 8 seconds
`opened` + `connected: false` + `note`	The URL went to the system default browser and no session showed up within 8 seconds. Almost always means the app carries no SDK, or dials a different port
`error`	No app connected and no URL given, or the browser could not be launched

connected is measured, not assumed. This command polls for a new session rather than printing {"opened": url} unconditionally, so a run where nothing opened no longer looks like one where it did. When the launcher itself cannot run, there is no opened field at all. Real capture:

{"event":"reticle_open","port":4499,"error":"could not launch a browser: spawn open ENOENT","recovery":"Nothing was opened. This command asks the OS to open a url in your default browser (`open` on this platform) and that failed, so the fix is on the OS side: open the url yourself, or set a default browser."}

Calling it with no URL when nothing has connected is the other error shape. It exits 0, because reporting “there is nothing to show you” is a complete answer. Real capture, with the sentence break shown as ...:

{"t":"2026-08-15T18:43:41.651Z","event":"reticle_open","port":4499,"error":"no app connected ... pass a url: reticle open <url>. Desktop app (Electron/Tauri)? There is no url to open: start it as you normally would and it connects to this bridge itself."}

This command does not use Reticle’s own Chromium. It hands the URL to your system default browser, so a chromium warning from reticle doctor has nothing to do with an open that came back connected: false. That misread cost a reporter an afternoon in their bridge config.

For an Electron or Tauri app there is no URL to open. Start the app the way you normally would; it dials the bridge itself.

Exit codes

Code	Meaning
`0`	Reused, opened, or reported that no app is connected
`1`	A browser could not be launched, or the daemon could not be reached

Worked example

npx @reticlehq/server open http://localhost:5173
npx @reticlehq/server status    # confirm the session is really there

Tools

Beyond the loop

CLI commands

Packages

Grammar

Long form

reticle open

Arguments and flags

What it prints

Exit codes

Worked example