What happens when you create an app: the platform provisions that app's own AWS back-end — a private S3 bucket, a Cognito sign-in client, a scoped developer access key, and an auto-generated developer guide — in about a minute. You don't touch AWS.

1. App ID — a short lowercase slug (letters, digits, hyphens), e.g. trailmates. It's permanent and names all of the app's resources.
2. Display name — human-readable, e.g. "TrailMates".
3. General APIs — check the capabilities this app may use: storage (per-user files), data (per-user documents / cross-device sync), ai (Bedrock models), groups (sharing), messaging (SMS/push).
4. Click Create & provision. Status shows PROVISIONING → ACTIVE (hit Refresh after ~1 minute).

Then hand your developer two things: (1) the app's developer access key — stored securely in AWS Secrets Manager as cpa/<appId>/dev-credentials; and (2) the auto-generated developer guide. They drop the guide into their Claude Code project and build against the endpoints — no AWS knowledge required. The key is fenced to that app's resources only.

Good to know: the inexpensive AI models (Amazon Nova, DeepSeek, Llama) work immediately. Anthropic (Claude) models and SMS require a one-time account setup — see the AWS account setup runbook (AWS-ACCOUNT-SETUP.md). Deleting an app leaves its data bucket behind on purpose (to protect user data); reclaim it anytime from Orphaned data below.

App Cloud Kit gives an app a ready-made "backend in the cloud." A developer can build an app that does the things modern apps do — without setting up any servers or databases themselves:

• User accounts & login — people sign up (email, phone, or username) and log in.
• Cloud storage for files — each user saves and loads their own files from any device.
• A cloud database — save each user's data (settings, scores, notes); it syncs across their devices.
• AI — send text to an AI model and get an answer back.
• Sharing (Groups) — users form groups and share data (a project, a game room, a chat).
• Live / real-time — devices talk to each other instantly (chat, multiplayer, presence).
• Custom code — run small backend functions for anything special.

For example, a developer could build an app where users sign up, log in, and save notes that appear on all their devices; a photo app where each person sees only their own pictures; a group chat or multiplayer game with live updates; or an app that summarizes text with AI.

How a developer uses it: they don't wire any of this up by hand. You create an application here, then give them its developer guide (the Guide ⬇ button in the Applications list). They drop that file into a Claude Code project, add the credentials it lists, and ask Claude Code to build what they want — Claude Code reads the guide and does the rest. The guide is written for beginners and includes copy-paste setup.