---
title: Apps
description: What an account holder can do with an app — deploy it, configure it, observe it.
---

An app is a celld Worker with a `git` remote. The owner creates it in the UI; deploys follow every push to that remote.

1. **Deploy**

    Push code over Git smart-HTTP or from CI. Each push builds, releases, and goes live behind `http://<slug>.<domain>`.

2. **Configure**

    Env vars, custom domains, collaborators, source edits, and storage inspection — all from the app detail page.

3. **Observe**

    Runtime logs, request metrics with spans, product-analytics events, and idle sleep behavior.

**[Deploy](/apps/deploy)**

Create an app, push with git, deploy from CI, and what each push triggers.

**[Configure](/apps/configure)**

Env vars, custom domains, collaborator roles, web commits, and storage.

**[Observe](/apps/observe)**

Logs, metrics and spans, events and insights, and scale-to-zero sleep.

App slugs are 1–48 chars: lowercase letters, digits, hyphens, starting and ending with a letter or digit. Reserved: `_control`, `app`, `api`, `git`.