Skygen – Rust OpenAPI v3 SDK Generator

Skygen is a Rust command line tool that turns an OpenAPI v3 specification into an idiomatic Rust SDK. It can generate SDKs for Cloudflare, DigitalOcean, Exoscale, Hetzner, Scaleway and any provider that publishes an OpenAPI spec.

Installation

cargo install --path ./skygen

Usage

skygen generate --schema <schema-file> --output-dir <output-directory> --config <config-file>

Configuration

Skygen uses a TOML configuration file to customize the generated SDK. Here's an example configuration:

crate_name = "my-cloud-sdk"
version = "0.1.0"
edition = "2021"
description = "A Rust SDK for My Cloud Provider API"
lib_status = "active"
keywords = ["cloud", "api", "sdk"]
api_url = "https://api.mycloudprovider.com"
authors = ["Cloudflavor GmbH <foss@cloudflavor.io>"]

Configuration Options

• crate_name: The name of the generated Rust crate
• version: The version of the generated crate
• edition: The Rust edition to use (defaults to "2021")
• description: A brief description of the crate
• lib_status: The maintenance status of the library (e.g., "active", "deprecated", "experimental")
• keywords: A list of keywords for the crate
• api_url: The base URL for the API
• authors: A list of authors for the crate
• include_only: (Optional) A list of models to include (if not specified, all models are included)
• exclude: (Optional) A list of models to exclude

Generating the SDK

skygen generate \
  --schema path/to/openapi.yaml \
  --config config.toml \
  --output-dir ./output

The output will contain a Cargo crate with a typical src/ layout and a Cargo.toml that exposes optional features like rustls, native-tls and http2.

Generated Structure

The generated SDK includes:

• src/lib.rs: Main library entry point
• src/client.rs: HTTP client implementation
• src/errors.rs: Error types
• src/models/: Generated model types
• src/apis/: Generated API operation functions
• Cargo.toml: Crate metadata and dependencies

Features

• Full OpenAPI v3 specification support
• Automatic model generation from schemas
• HTTP client with request/response handling
• Error type generation
• Support for complex schema types (arrays, objects, references, oneOf, anyOf, allOf)
• Rust code formatting with cargo fmt

Project Structure

src/ ├─ lib.rs ├─ client.rs ├─ errors.rs ├─ models/ └─ apis/

Contributing

See CONTRIBUTING.md for details.

License

Apache‑2.0 – see the LICENSE file.