# Logging & debugging

Studio records what your code does on every request, so you can see exactly why a notification was — or wasn't — sent.

## console.log

Use `console.log(...)` (and `console.warn`, `console.error`) anywhere in your code. The output is captured **per request** and shown in the **Console** tab of [Request history](/introduction/justpush-studio/testing-and-monitoring/request-history.md).

```javascript
console.log("Incoming event:", request.body.event)

if (!request.body.user) {
    console.warn("No user in payload")
    return
}

console.log("Sending notification for", request.body.user)
return {
    title: "New activity",
    message: request.body.user
}
```

## What each request records

For every webhook that arrives, Studio stores:

* the request **method**, **headers**, and **body** (what came in),
* your code's **console output** (what it logged),
* the **status / result** of the run, and
* which **revision** of your code handled it.

Open any request in the [request history](/introduction/justpush-studio/testing-and-monitoring/request-history.md) to inspect all of this.

## A debugging loop that works

1. Send a real (or [test](/introduction/justpush-studio/testing-and-monitoring/testing-your-code.md)) request.
2. Open it in request history and read the **Console** tab.
3. Add `console.log` lines around the part that's misbehaving.
4. **Save** a new revision and send the request again.

## Common things to check

* **Reading the wrong field.** Log `request.body` to see the actual structure the provider sends — it's often nested.
* **Nothing returned.** If your code never returns a message (or hits an early `return`), no notification is sent. That's expected for filtered events, but log a line so you know it was intentional.
* **Wrong revision live.** Make sure you **saved** after your last edit — the editor shows "Not saved yet" until you do. See [Revisions](/introduction/justpush-studio/revisions/revisions.md).


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