mikro-typebox

Generate validation schemas from Mikro-ORM entities. Supports TypeBox, Zod, Valibot, ArkType, Effect, io-ts, Yup, and more.

Features

• 🏗️ Entity Type Generation: Converts Mikro-ORM entity classes to TypeScript types
• 🔄 Multiple Validation Libraries: Supports TypeBox, Zod, Valibot, ArkType, Effect, io-ts, Yup, and more
• 🎯 Smart Type Resolution: Automatically resolves entity references depending on the relation graph between entities and sorts them by dependency order
• 🔄 Circular Reference Handling: Automatically breaks circular references to avoid infinite recursion
• 🔄 Partial Types: Generates partial types for entities with optional properties
• 📦 Collection Handling: Handles Collection<T> and Array<T> with proper type mapping

Installation

npm install --save-dev mikro-typebox

CLI Usage

The package includes a command-line interface for easy usage:

Generate typebox schema from ./src/entities to ./src/entity-validators.ts

npx mikro-typebox generate

Generate Zod schema from ./src/entities to ./src/entity-validators.ts

npx mikro-typebox generate --target zod

Generate Valibot schema from ./src/models to ./src/validators.ts

npx mikro-typebox generate --target valibot --entities ./src/models --output ./src/validators.ts

CLI Options

generate command

• -e, --entities <path>: Directory containing entity files (default: ./src/entities)
• -o, --output <file>: Output file path (default: ./src/entity-validators.ts)
• --no-write: Print the code to the console instead of writing to a file (default: writes to a file)
• -t, --target <library>: Target validation library (default: typebox)
• --partials, --no-partials: Generate partial types instead of inline primary key references (default: true for typebox)

Supported Validation Libraries

• typebox - TypeBox (default)
• zod - Zod
• valibot - Valibot
• arktype - ArkType
• effect - Effect
• io-ts - io-ts
• yup - Yup
• json-schema - JSON Schema
• javascript - JavaScript
• typescript - TypeScript
• value - Value

Programmatic Usage

You can also use the API to generate validation schemas programmatically.

generateEntityValidator(options)

Generates validation schemas from Mikro-ORM entities.

Parameters

• options.entitiesDir (optional): Directory containing the entity files (default: "./src/entities")
• options.outputFile (optional): File path to write the generated code (default: "./src/entity-validators.ts")
• options.write (optional): Whether to write the code to a file (default: true)
• options.targetValidationLibrary (optional): Target validation library (default: "typebox")
• options.partials (optional): Whether to generate partial types instead of inline primary key references (default: true for typebox)

generateEntityTypes(code, entityIdTypes)

Converts Mikro-ORM entity code to TypeScript types.

Parameters

• code: The entity code as a string
• entityIdTypes (optional): Map of entity names to their ID types

generateEntityFileTypes(fileContents)

Processes multiple entity files and generates types with proper entity ID replacement.

Parameters

• fileContents: Array of entity file contents as strings

Usage Examples

import { generateEntityValidator } from "mikro-typebox";

// Generate for TypeBox
await generateEntityValidator({
  entitiesDir: "./src/entities",
  outputFile: "./src/validators.ts",
  write: true,
  partials: true,
});

// Generate for Zod
const zodCode = await generateEntityValidator({
  entitiesDir: "./src/entities",
  targetValidationLibrary: "zod",
  outputFile: "./src/zod-validators.ts",
  write: true,
});

// Generate for Valibot
const valibotCode = await generateEntityValidator({
  entitiesDir: "./src/entities",
  targetValidationLibrary: "valibot",
  outputFile: "./src/valibot-validators.ts",
  write: true,
});

Working with Entity Files

Given a Mikro-ORM entity file like this:

// src/entities/User.ts
import {
  Entity,
  PrimaryKey,
  Property,
  Collection,
  OneToMany,
} from "@mikro-orm/core";
import { Book } from "./Book";

@Entity()
export class User {
  @PrimaryKey()
  id!: number;

  @Property()
  name!: string;

  @Property()
  email!: string;

  @OneToMany(() => Book, (book) => book.author)
  books = new Collection<Book>(this);

  constructor({ name, email }: User) {
    this.name = name;
    this.email = email;
  }
}

// src/entities/Book.ts
import { Entity, PrimaryKey, Property, ManyToOne } from "@mikro-orm/core";
import { User } from "./User";

@Entity()
export class Book {
  @PrimaryKey()
  id!: number;

  @Property()
  title!: string;

  @ManyToOne(() => User)
  author!: User;

  constructor({ title, author }: Book) {
    this.title = title;
    this.author = author;
  }
}

And then generate validation schemas (e.g., with TypeBox):

import { Type, Static, TSchema } from "@sinclair/typebox";

export namespace schema {
  export type Collection<T extends TSchema> = Static<
    ReturnType<typeof Collection<T>>
  >;
  export const Collection = <T extends TSchema>(T: T) =>
    Type.Object(
      {},
      {
        additionalProperties: T,
      },
    );

  export type Book = Static<typeof Book>;
  export const Book = Type.Object({
    id: Type.Number(),
    title: Type.String(),
    author: schema.PartialUser,
  });

  export type PartialBook = Static<typeof PartialBook>;
  export const PartialBook = Type.Object({
    id: Type.Number(),
    title: Type.Optional(Type.String()),
    author: Type.Optional(schema.PartialUser),
  });

  export type User = Static<typeof User>;
  export const User = Type.Object({
    id: Type.Number(),
    name: Type.String(),
    email: Type.String(),
    books: Type.Union([
      Collection(
        Type.Object({
          id: Type.Number(),
        }),
      ),
      Type.Array(
        Type.Object({
          id: Type.Number(),
        }),
      ),
    ]),
  });

  export type PartialUser = Static<typeof PartialUser>;
  export const PartialUser = Type.Object({
    id: Type.Number(),
    name: Type.Optional(Type.String()),
    email: Type.Optional(Type.String()),
    books: Type.Optional(
      Type.Union([
        Collection(
          Type.Object({
            id: Type.Number(),
          }),
        ),
        Type.Array(
          Type.Object({
            id: Type.Number(),
          }),
        ),
      ]),
    ),
  });
}

or for Zod

import { z } from "zod";

export type schema_Book = z.infer<typeof schema_Book>;
export const schema_Book = z.object({
  id: z.number(),
  title: z.string(),
  author: z.object({
    id: z.number(),
  }),
});

export type schema_User = z.infer<typeof schema_User>;
export const schema_User = z.object({
  id: z.number(),
  name: z.string(),
  email: z.string(),
  books: z.union([
    z.object({}),
    z.array(
      z.object({
        id: z.number(),
      }),
    ),
  ]),
});

Programmatic Usage

import { generateEntityTypes, generateEntityFileTypes } from "mikro-typebox";

// Process a single entity file
const entityCode = `
import { Entity, PrimaryKey, Property } from '@mikro-orm/core';

@Entity()
export class Product {
  @PrimaryKey()
  id!: number;

  @Property()
  name!: string;
}
`;

const types = generateEntityTypes(entityCode);
console.log(types);
// Output: export type Product = { id: number; name: string; };

// Process multiple entity files
const fileContents = [entityCode, anotherEntityCode];
const allTypes = generateEntityFileTypes(fileContents);

How It Works

1. Entity Discovery: Scans entity files for classes decorated with @Entity()
2. Type Extraction: Extracts property types and relationships from entity classes
3. ID Type Resolution: Replaces entity references with their primary key types
4. Collection Conversion: Converts Collection<T> to Array<T> with proper type mapping
5. Code Cleanup: Removes Mikro-ORM specific imports, decorators, and method calls
6. Schema Generation: Converts TypeScript types to validation schemas using the target library

License

Apache-2.0, Copyright (c) 2025 Amin Yara