Analytics for vibe coded apps.

Adding analytics to a site built with an AI coding agent is a small job, and agents can make it big. The cheapest setup is one script tag in the head of every page, then opening the live site to check that your own visit shows up. Most of the trouble comes from skipping that last check.

• February 2025

  is when Andrej Karpathy posted the phrase "vibe coding" on X. He described asking an AI for what you want and accepting its changes without reading them. The word stuck. Andrej Karpathy on X

• 84 in 100

  developers who answered the Stack Overflow 2025 survey were using or planning to use AI tools in their work. That was up from 76 in 100 the year before. Stack Overflow

• 51 in 100

  professional developers in the same survey used AI tools every day. Stack Overflow

• 15 in 100

  said vibe coding is part of their professional work, at least somewhat. 77 in 100 said it is not. So most developers still read what the agent wrote, and the people shipping without reading it are a minority at work. Stack Overflow

• 1 in 4

  startups in Y Combinator's Winter 2025 batch had codebases that were 95 in 100 written by AI, according to managing partner Jared Friedman. He said the figure left out library imports, and that these founders were technical. TechCrunch

• 66 in 100

  developers in the Stack Overflow survey named "AI solutions that are almost right, but not quite" as their top frustration. Analytics code is a good place for almost right, because nothing visibly breaks when it does not work. Stack Overflow

1. 01Nobody checked that data arrives

   This is the most common failure and the easiest to miss. The agent writes the code, the build passes, the site looks fine, and no visit was ever counted. The page gives you no sign.

   TRY THISAsk the agent to open the live site after the change and confirm one visit shows up in your dashboard. Or do it yourself: open the site and watch for the first visit. An ad blocker can hide your own visit, so try a window without one.

2. 02Only the first page counts

   A React or Next.js app does not reload when someone clicks a link. It swaps the page in place. A tag that only fires on page load sees the first page and misses the rest. Google Analytics has a setting for this. It listens for pushState, popState and replaceState, the browser calls an app makes when it changes the address. Google Analytics Help

   TRY THISUse a tracker that follows those calls. The Moxel script does. It starts a new page view whenever the path changes, so Next.js links count. A change to only the query string, like ?tab=2, does not. Click through three pages on your own site and check that three show up.

3. 03The agent picks a heavy tool for a team

   Asked to add analytics, an agent may reach for whatever it has seen most. That can be a full product-analytics package with an SDK, an event schema and logins for teammates. You have no teammates. There is no study on how often this happens, so treat it as a pattern to watch for, not a measured rate.

   TRY THISName the tool and the method in the prompt. Say "paste this one script tag, add no packages". A tag in the head is one line to read and one line to remove.

4. 04Cookies arrive, then a consent banner

   Some analytics code stores something in the visitor's browser. Then the site needs a banner asking permission, and the agent adds one. Your page now has a popup over the first screen that nobody asked for.

   TRY THISPick a tool that stores nothing in the browser, and say so in the prompt. Moxel sets no cookies and keeps nothing in the visitor's browser. If you use another tool, read what it stores before the agent writes a banner.

5. 05Event names drift

   Ask an agent for custom events in three sessions and you can get signup, Signup and user_signed_up. They count as three different things, and none adds up to the number you wanted.

   TRY THISSkip custom events at first. Page views, forms and clicks cover most early questions. If you add one, write the name once in the prompt and tell the agent to reuse it. Moxel names forms and fields from what is already on the page, so there is nothing for the agent to invent.

6. 06The key ends up in the wrong place

   Some tools have two keys. One is public and belongs in the page. One is secret and belongs on a server. An agent can paste the secret one into front-end code, where anyone can read it.

   TRY THISPut only the public site key in the script tag. Keep a secret key, if you use one, in an environment variable on the server and never in a file the browser loads. In Moxel, the key inside the script tag is the public one.