Skip to main content

CLI Usage

The @apical-ts/craft CLI tool allows you to generate TypeScript clients and schemas from OpenAPI specifications with a simple command-line interface.

Basic Usage​

Generate schemas and client code from an OpenAPI specification:

npx @apical-ts/craft generate \
  --server \
  --client \
  -i https://petstore.swagger.io/v2/swagger.json \
  -o generated

This command will:

  1. Download the OpenAPI specification from the provided URL
  2. Generate Zod schemas for all data models
  3. Generate client operation functions (if --client is specified)
  4. Generate server handler wrappers (if --server is specified)
  5. Output all generated files to the generated directory

Runtime Dependencies​

The generated client and server code requires zod as a runtime dependency for schema validation. After generation, install it in your output directory:

cd generated
npm install

Watch Mode​

You can run the CLI in watch mode to automatically regenerate code when your OpenAPI specification file changes:

npm install chokidar-cli @apical-ts/craft
npm exec -- chokidar-cli openapi.yaml -c \
  "craft generate \
  --server \
  --client \
  -i openapi.yaml \
  -o generated"

This is particularly useful during development when you're iterating on your API specification.

CLI Options​

Required Options​

  • -i, --input <path>: Path to the OpenAPI spec file (2.0, 3.0.x, or 3.1.x) in YAML or JSON format. Can be a local file path or a remote URL.
  • -o, --output <path>: Output directory for generated code

Generation Options​

  • --client: Generate the operation functions for client-side usage (default: false)
  • --server: Generate the operation wrapper functions for server-side usage (default: false)
  • --routes: Generate route metadata only (default: false). Useful when you want to generate your own type-safe client or server implementation while leveraging the generated schemas and route definitions.
  • --extra-props <mode>: Control how Zod schemas handle additional properties. Options: strip (default), loose, strict. See Schema Validation Modes for details.

Note: The long-form flags --generate-client, --generate-server, and --generate-routes are deprecated in favor of the shorter --client, --server, and --routes aliases.

Output Structure​

The generated output follows a consistent structure:

generated/
├── client/           # Client operation functions (if --client)
├── routes/           # Route metadata (if --routes, --client, or --server)
├── server/           # Server handler wrappers (if --server)
└── schemas/          # Zod schemas and TypeScript types

Each directory contains:

  • An index.ts file that exports all the generated code
  • Individual files for each operation or schema
  • TypeScript declaration files for full type safety

The output directory will be created if it doesn't exist and existing files will be overwritten.

Custom Client or Server Implementation​

If you want to build your own type-safe client or server implementation while leveraging the generated schemas and route metadata, use the --routes flag:

npx @apical-ts/craft generate \
  --routes \
  -i openapi.yaml \
  -o generated

This generates:

  • Schemas: Full Zod v4 schemas with TypeScript type inference
  • Routes: Route metadata including paths, HTTP methods, parameters, and request/response types

You can then build your own client or server using these generated artifacts. For example, you might want to:

  • Create a custom HTTP client with specific retry logic or authentication
  • Build a server using a framework not directly supported (e.g., Fastify, Koa, Hono)
  • Generate GraphQL resolvers or tRPC procedures from REST definitions
  • Create mock servers or testing utilities

The route metadata provides all the type information you need, while the schemas handle runtime validation.

Formatting Generated Code​

For performance reasons, the CLI does not format the generated TypeScript files by default. To format them you may use Biome running the following command in the output directory:

npx @biomejs/biome format --write .

Alternatively, you can use any other slower code formatter of your choice, e.g.

npx prettier --log-level=silent --write .