App

An App is the root of every cdkx program. It owns the construct tree, drives the synthesis pipeline, and writes the cloud assembly to disk.

What it does

• Acts as the parent scope for all Stack instances
• Caches one resolver pipeline per provider (built lazily on first use)
• When app.synth() is called, it traverses all stacks, synthesizes each one, and writes manifest.json

Basic usage

import { App, Stack } from '@cdk-x/core';

const app = new App(); // (1)!

const stack = new Stack(app, 'MyStack'); // (2)!
// ... add resources to stack ...

app.synth(); // (3)!

1. Creates the root of the construct tree. outdir defaults to cdkx.out/ relative to the working directory.
2. Stacks are added as direct children of the App.
3. Triggers synthesis — writes all stack files and manifest.json. Must be the last call in every entrypoint.

Custom output directory

const app = new App({ outdir: 'dist/assembly' });

Global resolvers

Resolvers transform token values during synthesis (e.g. turning a SecretRef into a provider-specific string). Global resolvers run before any provider-specific resolver — useful for cross-provider tokens:

const app = new App({
  resolvers: [mySecretResolver],
});

Constructor props

Prop	Type	Default	Description
outdir	string	'cdkx.out'	Output directory for the cloud assembly
resolvers	IResolver[]	[]	Global resolvers prepended to every stack's pipeline

Static helpers

// Walk up the construct tree to find the root App. Throws if the construct
// is not rooted in an App.
const app = App.of(someNestedConstruct);

// Type guard
App.isApp(x); // true | false

What app.synth() produces

cdkx.out/
├── manifest.json       # index of all stacks and their artifact IDs
├── MyStack.json        # synthesized resources for MyStack
└── OtherStack.json     # synthesized resources for OtherStack

See Cloud Assembly for the full output format.

---

See also

• Stack — a deployment unit that lives inside an App
• Cloud Assembly — what app.synth() writes to disk
• Tokens — how cross-resource references are resolved during synthesis