@cerios/openapi-to-typescript

Generate TypeScript types from OpenAPI specifications.

Features

• Generate TypeScript type declarations from OpenAPI schemas
• Generate TypeScript enum, union, or const object from OpenAPI enums
• Configurable output format options
• CLI and programmatic API
• Supports OpenAPI 3.0 and 3.1

Installation

npm install @cerios/openapi-to-typescript

Quick Start

CLI Usage

# Initialize a config file
npx openapi-to-typescript init

# Generate types
npx openapi-to-typescript generate

Configuration

Create a openapi-to-typescript.config.ts file:

import { defineConfig } from "@cerios/openapi-to-typescript";

export default defineConfig({
	input: "./openapi.yaml",
	outputTypes: "./src/types.ts",

	// Output format for enums: 'enum', 'union' (default), or 'const-object'
	enumFormat: "union",
});

Programmatic API

import { TypeScriptGenerator } from "@cerios/openapi-to-typescript";

const generator = new TypeScriptGenerator({
	input: "./openapi.yaml",
	outputTypes: "./src/types.ts",
	enumFormat: "union",
});

// Generate and write to file
generator.generate();

// Or generate as string
const code = generator.generateString();

Configuration Options

| Option | Type | Default | Description | | --------------------- | ------------------------------------- | --------- | --------------------------------------------------------------- | | input | string | - | Path to OpenAPI specification (YAML or JSON) | | outputTypes | string | - | Output file path for generated types | | enumFormat | 'enum' \| 'union' \| 'const-object' | 'union' | How to generate enums | | includeDescriptions | boolean | true | Include JSDoc comments | | defaultNullable | boolean | false | Treat properties as nullable by default | | stripSchemaPrefix | string \| string[] | - | Remove prefix from schema names (supports glob) | | stripPathPrefix | string | - | Remove prefix from paths | | useOperationId | boolean | true | Use operationId for operation-derived type names when available | | prefix | string | - | Add prefix to generated type names | | suffix | string | - | Add suffix to generated type names | | operationFilters | object | - | Filter operations by tags, paths, methods | | showStats | boolean | true | Include generation statistics | | batchSize | number | 10 | Parallel processing batch size |

Output Format Examples

Enum Format

union (default):

export type Status = "active" | "inactive" | "pending";

enum:

export enum Status {
	Active = "active",
	Inactive = "inactive",
	Pending = "pending",
}

const-object:

export const Status = {
	Active: "active",
	Inactive: "inactive",
	Pending: "pending",
} as const;
export type Status = (typeof Status)[keyof typeof Status];

License

MIT