Installation

Five minutes from zero to a project that loads Cascade. No conceptual content on this page — pure mechanics. Three steps: install the packages, install your driver, turn on decorators. If you’re done before your coffee finishes brewing, that’s the right amount of time.

Prerequisites

• Node.js 20+ (current active LTS).
• TypeScript 5+ in the project.
• A database — either MongoDB or PostgreSQL — running locally or reachable by connection string. If you don’t have one yet, install MongoDB or PostgreSQL first. Cascade works the same against either.

Step 1 — Install Cascade and seal

Cascade ships with @warlock.js/seal as a dependency, but you’ll import directly from seal in your schemas (v and Infer). Install both explicitly so they’re both in your package.json — stricter package managers (pnpm strict mode, Yarn PnP) need it.

import { Tabs, TabItem } from “@astrojs/starlight/components”;

npm install @warlock.js/cascade @warlock.js/seal

pnpm add @warlock.js/cascade @warlock.js/seal

yarn add @warlock.js/cascade @warlock.js/seal

bun add @warlock.js/cascade @warlock.js/seal

Both packages are now in your package.json. You’ll import the ORM bits (Model, RegisterModel, relation helpers) from @warlock.js/cascade, and the schema bits (v, Infer) from @warlock.js/seal.

Step 2 — Install your database driver

Cascade speaks MongoDB and PostgreSQL through separate peer dependencies. Install the one you’re using:

For MongoDB:

npm install mongodb

For PostgreSQL:

npm install pg

That’s the entire driver story from the install side. Cascade picks it up via configuration on the next page — you don’t import it directly.

Step 3 — Turn on decorators

Cascade uses @RegisterModel() to put each model into a global registry, and @BelongsTo / @HasMany / etc. to declare relations. If decorators don’t run, the registry stays empty, decorator-based relations never hoist, and your models break at runtime with confusing errors.

So: turn decorators on. Mandatory, not optional.

Add this to your tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2022",
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "strict": true
  }
}

Three things this does:

• experimentalDecorators makes @RegisterModel() compile.
• emitDecoratorMetadata lets Cascade read decorator-attached metadata at runtime.
• strict catches the kind of schema-vs-class drift you want to know about at compile time, not at 2am.

Recap

You’ve got:

• Cascade and seal installed
• One database driver installed (Mongo or Postgres)
• TypeScript ready for decorators

Nothing’s running yet — that’s the next page.

Next

Continue to Configuration to connect Cascade to your database.