@blimu/codegen

A powerful TypeScript library and CLI tool for generating type-safe SDKs from OpenAPI specifications. Built with NestJS Commander and following NestJS conventions.

Features

• 🚀 Multiple Language Support: TypeScript, Go, Python (with more planned)
• 📝 OpenAPI 3.x Support: Full support for modern OpenAPI specifications
• 🎯 Tag Filtering: Include/exclude specific API endpoints by tags
• 🔧 Highly Configurable: Flexible configuration via MJS config files with TypeScript hints
• 📦 Library & CLI: Use as a TypeScript library or standalone CLI tool
• 🎨 Beautiful Generated Code: Clean, idiomatic code with excellent TypeScript types
• ⚡ Function-Based Transforms: Use JavaScript functions for operationId transformation with full type safety

Installation

yarn add @blimu/codegen
# or
npm install @blimu/codegen

CLI Usage

Using Command Line Arguments

# Generate TypeScript SDK from OpenAPI spec
codegen generate \
  --input https://petstore3.swagger.io/api/v3/openapi.json \
  --type typescript \
  --out ./petstore-sdk \
  --package-name petstore-client \
  --client-name PetStoreClient

Using Configuration File

The CLI automatically looks for chunkflow-codegen.config.mjs in the current directory and parent directories. You can also specify a custom path:

# Auto-discover chunkflow-codegen.config.mjs
codegen generate

# Use explicit config file path
codegen generate --config ./chunkflow-codegen.config.mjs

# Generate only a specific client from config
codegen generate --client MyClient

Configuration File Example

Create chunkflow-codegen.config.mjs in your project root:

// @ts-check
import { defineConfig } from '@blimu/codegen';

export default defineConfig({
  spec: 'http://localhost:3020/docs/backend-api/json',
  clients: [
    {
      type: 'typescript',
      outDir: './my-sdk',
      packageName: 'my-sdk',
      name: 'MyClient',
      operationIdParser: (operationId, method, path) => {
        // Custom transform logic
        return operationId.replace(/Controller/g, '');
      },
    },
  ],
});

The // @ts-check directive enables TypeScript type checking and autocomplete in your config file!

See examples/chunkflow-codegen.config.mjs.example for a complete example with all available options.

Programmatic API

Use the codegen library programmatically in your TypeScript code:

import { generate, loadConfig, defineConfig } from '@blimu/codegen';

// Generate from config object
await generate({
  spec: 'http://localhost:3020/docs/backend-api/json',
  clients: [
    {
      type: 'typescript',
      outDir: './my-sdk',
      packageName: 'my-sdk',
      name: 'MyClient',
      operationIdParser: (operationId, method, path) => {
        return operationId.replace(/Controller/g, '');
      },
    },
  ],
});

// Generate from config file path
await generate('./chunkflow-codegen.config.mjs');

// Generate only a specific client
await generate('./chunkflow-codegen.config.mjs', { client: 'MyClient' });

// Load config programmatically
const config = await loadConfig('./chunkflow-codegen.config.mjs');

Configuration Options

Top-Level Config

• spec (required): OpenAPI spec file path or URL
• name (optional): Name for this configuration
• clients (required): Array of client configurations

Client Configuration

• type (required): Generator type (e.g., 'typescript')
• outDir (required): Output directory for generated SDK
• packageName (required): Package name for the generated SDK
• name (required): Client class name
• moduleName (optional): Module name for type augmentation generators
• includeTags (optional): Array of regex patterns for tags to include
• excludeTags (optional): Array of regex patterns for tags to exclude
• includeQueryKeys (optional): Generate query key helper methods
• operationIdParser (optional): Function to transform operationId to method name
  • Signature: (operationId: string, method: string, path: string) => string | Promise<string>
• preCommand (optional): Commands to run before SDK generation
• postCommand (optional): Commands to run after SDK generation
• defaultBaseURL (optional): Default base URL for the client
• exclude (optional): Array of file paths to exclude from generation

License

MIT