TypeSpec Drizzle Emitter

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A TypeSpec emitter that generates Drizzle ORM schema definitions and types from TypeSpec specifications. Learn about TypeSpec emitters here.

Important

Project Status: 🚧 This project is brand new. Use at your own risk.

Overview

This emitter allows you to define your database schema using TypeSpec's type-safe language with specialized decorators and automatically generate Drizzle ORM schema files, enabling a single source of truth for your database schema definitions alongside other artifacts.

Features

• Generate Drizzle schema definitions from TypeSpec models
• Decorator-based configuration for database-specific concerns
• Support for table customization, constraints, and relationships
• Primary keys, unique constraints, indexes, and default values
• One-to-one, one-to-many, and many-to-many relationships
• Junction table support for many-to-many relationships
• Schema namespacing and custom table/column names
• Type-safe database schema generation
• Integration with TypeSpec's existing ecosystem

Installation

bun add -D @omnidotdev/typespec-drizzle

Usage

Basic Usage

1. Add the emitter to your TypeSpec configuration (tspconfig.yaml):

emit:
  - "@omnidotdev/typespec-drizzle"

2. Define your models in TypeSpec with decorators:

import "@omnidotdev/typespec-drizzle";

@table({ name: "users" })
model User {
  @id
  id: string;

  @unique
  email: string;

  name: string;

  @default("now()")
  createdAt: utcDateTime;
}

@table({ name: "posts" })
model Post {
  @id
  id: string;

  title: string;
  content: string;

  @manyToOne({
    foreignKey: "authorId",
    references: "id",
  })
  authorId: string;

  @default("now()")
  createdAt: utcDateTime;
}

3. Add a tspconfig.yaml file:

emit:
  - "@omnidotdev/typespec-drizzle"
  - "@typespec/json-schema"
options:
  "@omnidotdev/typespec-drizzle":
    outputDir: "./tsp-output"

4. Run the TypeSpec compiler:

tsp compile .

The emitter will generate Drizzle schema files in the output directory, plus JSON schemas for your models.

Decorators

Table Decorators

@table(options?)

Mark a model as a database table.

@table({ name: "custom_users", schema: "auth" })
model User {
  // ...
}

Options:

• name?: string - Custom table name (defaults to model name in lowercase)
• schema?: string - Database schema name

@junction

Mark a model as a junction table for many-to-many relationships.

@junction
@table({ name: "user_roles" })
model UserRole {
  @manyToOne({ foreignKey: "userId", references: "id" })
  userId: string;

  @manyToOne({ foreignKey: "roleId", references: "id" })
  roleId: string;
}

Column Decorators

@column(options?)

Configure column-specific options.

@column({ name: "user_email" })
email: string;

Options:

• name?: string - Custom column name (defaults to property name)

@id

Mark a property as the primary key.

@id
id: string;

@autoIncrement

Mark a numeric primary key as auto-incrementing.

@id
@autoIncrement
id: int64;

@default(value)

Set a default value for a column.

@default("'active'")
status: string;

@default("now()")
createdAt: utcDateTime;

@default("0")
count: int32;

@default("false")
isActive: boolean;

@unique(name?)

Add a unique constraint to a column.

@unique("unique_email")
email: string;

@unique  // Uses default constraint name
username: string;

@index(name?)

Add an index to a column.

@index("idx_created_at")
createdAt: utcDateTime;

@index  // Uses default index name
title: string;

Relationship Decorators

@oneToOne(options?)

Define a one-to-one relationship.

@oneToOne({ foreignKey: "profileId", references: "id" })
profileId: string;

@oneToMany(options?)

Define a one-to-many relationship.

@oneToMany({ foreignKey: "categoryId", references: "id" })
posts: Post[];

@manyToOne(options?)

Define a many-to-one relationship.

@manyToOne({ foreignKey: "authorId", references: "id" })
authorId: string;

@manyToMany(options)

Define a many-to-many relationship.

@manyToMany({ through: "post_tags" })
tags: Tag[];

Relationship Options:

• foreignKey?: string - Name of the foreign key field
• references?: string - Field in the target table (defaults to "id")
• through?: string - Junction table name (required for many-to-many)

Examples

Complete Blog Schema

import "@omnidotdev/typespec-drizzle";

@table({ name: "users" })
model User {
  @id
  id: string;

  @unique
  @index("idx_username")
  username: string;

  @unique
  @index("idx_email")
  email: string;

  @default("now()")
  createdAt: utcDateTime;
}

@table({ name: "categories" })
model Category {
  @id
  id: string;

  @unique
  name: string;

  @manyToOne({ foreignKey: "parentId", references: "id" })
  parentId?: string;
}

@table({ name: "posts" })
model Post {
  @id
  id: string;

  title: string;
  content: string;

  @manyToOne({ foreignKey: "authorId", references: "id" })
  authorId: string;

  @manyToOne({ foreignKey: "categoryId", references: "id" })
  categoryId?: string;

  @manyToMany({ through: "post_tags" })
  tags: Tag[];

  @default("now()")
  createdAt: utcDateTime;
}

@table({ name: "tags" })
model Tag {
  @id
  id: string;

  @unique
  name: string;

  @default("now()")
  createdAt: utcDateTime;
}

@junction
@table({ name: "post_tags" })
model PostTag {
  @id
  id: string;

  @manyToOne({ foreignKey: "postId", references: "id" })
  postId: string;

  @manyToOne({ foreignKey: "tagId", references: "id" })
  tagId: string;

  @default("now()")
  createdAt: utcDateTime;
}

Getting Started

Local Development

Use Tilt for a unified development experience:

tilt up

or manually install and build:

bun install
bun run build # or `bun run build:watch`

Tests can be run with bun test.

Contributing

See Omni's contributing docs.

License

The code in this repository is licensed under MIT, © Omni LLC. See LICENSE.md for more information.