schema-cast

A powerful code generation tool to create a single source-of-truth for your application's data layer.

Define your schema once in JSON or YAML, and schema-cast automatically generates:

1. TypeScript interfaces/types
2. Zod validation schemas
3. MongoDB (Mongoose) models
4. PostgreSQL CREATE TABLE SQL statements

Installation

npm install -g schema-cast
# OR
npx schema-cast generate ...

Usage

1. Define your Schema (user.schema.json)

{
  "name": "User",
  "fields": [
    { "name": "id", "type": "uuid", "required": true, "primary": true },
    { "name": "email", "type": "string", "required": true, "unique": true },
    { "name": "age", "type": "number", "required": false },
    { "name": "role", "type": "enum", "values": ["admin", "user", "guest"], "default": "user" },
    { "name": "createdAt", "type": "date", "required": true },
    { "name": "profile", "type": "object", "fields": [
      { "name": "bio", "type": "string" },
      { "name": "avatar", "type": "string" }
    ]}
  ]
}

Supported Field Types

• string, number, boolean, date, uuid, email, url, enum, object, array

Options

• required: boolean: Is the field required? (default: false)
• unique: boolean: Enforce unique constraint
• primary: boolean: Mark as Primary Key (used in Postgres, mapped to _id in Mongoose)
• default: any: Specify a default value
• values: string[]: Used specifically with enum type
• fields: FieldDefinition[]: Used specifically with object type
• items: FieldDefinition: Used specifically with array type

2. Generate Code

# Generate from a single file
schema-cast generate --input ./schemas/user.schema.json --out ./generated

# Process all schemas in a directory
schema-cast generate --all --input ./schemas/ --out ./generated

# Watch mode - automatically regenerate on save
schema-cast watch --input ./schemas/

Generated Files

The CLI will generate four files in the target directory per schema:

• user.types.ts: TypeScript definition
• user.zod.ts: Zod schema declaration
• user.model.ts: Mongoose model schema
• user.sql: PostgreSQL CREATE TABLE command

License

MIT