The Logs tab — what your app's server says
In shortThe Logs tab shows what your app's preview server prints — page reloads, updates and, most usefully, errors. Click Refresh for the latest lines. You rarely need to read it yourself. Ask in Chat mode, such as "Why does the booking page fail?", and MonstarX reads the logs, finds the cause and explains it without changing anything.
Behind the preview, a small server runs your app. It writes a running diary of what it does: which files it reloaded, which pages it updated and, when something goes wrong, the error. The Logs tab shows that diary.
What do the logs show?
Section titled “What do the logs show?”Open the Logs tab in the workspace header. At the top it says Dev server output with the number of lines, and on the right is a Refresh button. Below are the latest lines, newest at the bottom.
Most lines are routine — they say that a page or a style was updated after a change. The lines that matter are the errors: a page that failed to load, a request the server could not answer, a missing package.
Click Refresh to load the latest lines — up to the last 400. The same output is under Preview logs on the preview’s status card, for when the preview is taking a long time to start.
How do I use the logs to fix a problem?
Section titled “How do I use the logs to fix a problem?”You don’t have to read them yourself. MonstarX can read the logs in Chat and Build mode (not in Plan):
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Switch to Chat in the prompt box. See Build, Plan and Chat.
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Describe what you saw: “When I submit the booking form nothing happens. Can you check the logs?”
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MonstarX reads the preview’s latest logs, looks at the code and the data if it needs to, and explains the cause in plain words — without changing anything.
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If it proposes a fix, click Build this to have it made.
In Build mode MonstarX also reads the logs by itself when a change does not work as expected.
Why are the logs empty?
Section titled “Why are the logs empty?”- Nothing has happened yet. A freshly started preview has little to say: No output yet.
- The preview woke from sleep. After the preview sleeps and wakes, it may not show earlier output. Click Restart dev server (⟲) in the preview toolbar and reproduce the problem to get fresh logs.
Who can see the logs?
Section titled “Who can see the logs?”Only the project’s owner. People the project is shared with — to view and comment, or to edit — see the Preview and Code tabs, but not Logs.
Frequently asked questions
Section titled “Frequently asked questions”Are these the logs of my published app?
No. The Logs tab shows the preview you build with. Your published app runs separately.
How far back do the logs go?
Up to the last 400 lines of the preview's server. Older lines drop off, and a preview that stopped or slept starts with a fresh log.
I see lots of lines about updates and reloads. Is that a problem?
No. Those lines appear every time a file changes — they show the preview keeping up with MonstarX's edits.
Can I copy the logs to send to someone?
Yes, select the lines and copy them. To tell MonstarX about a problem, open Ask Luna and choose Report a bug with screenshots — it captures the page and the technical details for you. See Report a problem.