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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 opens a new one.

npx reticle open [url] [--port N]

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

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

What it prints

One reticle_open line, whose fields say which of four things 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
`opened` + `connected: true`	A browser was launched and a Reticle session appeared
`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."}

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 reticle open http://localhost:5173
npx reticle status    # confirm the session is really there

Last modified on August 14, 2026

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Beyond the loop

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Grammar

Long form

reticle open

Arguments and flags

What it prints

Exit codes

Worked example

​Arguments and flags

​What it prints

​Exit codes

​Worked example

Arguments and flags

What it prints

Exit codes

Worked example