Build and review
Preview and test your app
Open a static or hosted preview, check a meaningful result, and resolve missing assets, startup errors, and broken routes.
Check the app's behavior before sharing it. This guide covers static Browser projects and applications running in hosted Linux workspaces. A preview shows your development version; after publishing, check the public release separately.
Preview a Browser project
Use this path for plain HTML, CSS, JavaScript, and browser assets without a package installation or build step.
Let the active run finish, then open the app preview offered with its result.
Confirm the first page loads with its styles and images.
Click the main controls and try an invalid input.
Ask for a specific correction if the result differs from what you requested. Repeat the same action after the fix.
The first-app guide gives you a tip calculator with known results: a bill of 80, a 20% tip, and four people should produce $96.00 total and $24.00 per person.
The Browser agent can inspect and edit source files, but it cannot execute test commands or inspect the running page with browser automation. Your manual checks supply that evidence. If the project needs a server or build tool, use a hosted workspace.
Preview a hosted application
Start with the repository's README and dependency files. Ask the agent to install the required dependencies, start the development server, and provide its preview link. Read the command output before treating startup as successful.
The server must listen on 0.0.0.0 so the workspace preview can reach it. The correct flag depends on the framework. For an npm project whose dev script runs Vite, this is a typical command:
npm run dev -- --host 0.0.0.0
For a dev script that runs Next.js, use its hostname option:
npm run dev -- --hostname 0.0.0.0
Use the package manager and script declared by your project. Do not apply a framework flag to an unrelated command. See the Vite server options and Next.js CLI reference for those flags. Keep the server running and open the preview URL Rigless provides for its port.
In Advanced, the three-dot Session menu provides Terminal for reading output or running a command yourself. On a phone, use the code icon to enter Advanced first.
Give a check a clear expected result
For a form, try a valid submission, missing required values, and an error from the backend. For navigation, open a nested page directly and reload it. Try the same main task at desktop and phone widths.
In a hosted project, ask for checks the environment can execute:
Check the change we just made. Run the relevant repository tests and build
commands, and report the commands and results. If browser tools are available,
try the main interaction at desktop and phone widths. Tell me what you could
not check. Do not publish yet.
A passed build does not establish that every interaction works. Check the behavior you care about yourself, including anything the agent could not verify.
Resolve a blank or broken preview
What you see | What to check |
|---|---|
No preview for a Browser project | Ask the agent to check |
HTML loads without styling or behavior | Confirm the CSS and JavaScript files exist at the paths the HTML uses |
Hosted preview cannot connect | Check startup output, the listening port, and the |
A server starts and then stops | Read its error and fix missing packages or configuration |
A nested route fails on reload | Check the application's routing and server fallback behavior |
The published app differs from the preview | Check the production build, environment values, and public asset paths |
When the result works, follow Publish an app. Open the resulting public URL in a private browser window and repeat your main check there.
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