Nokturn – Rust OpenAPI v3 SDK Generator

Nokturn is a Rust toolchain that turns an OpenAPI v3 specification into an idiomatic Rust SDK. The nokturn-gen CLI can generate SDKs for Cloudflare, DigitalOcean, Exoscale, Hetzner, Scaleway and any provider that publishes an OpenAPI spec.

Workspace layout

• crates/nokturn-core: Loads OpenAPI v3 (JSON/YAML), applies a small sanitization pass, resolves component references, and defines the canonical IR for code generation.
• crates/nokturn-gen: CLI wrapper (binary name: nokturn-gen) that reads the config/spec, resolves the schema, and is the home for upcoming SDK generation.

Status

Code generation is in progress. Today nokturn-gen generate validates the config and resolves the OpenAPI spec, but does not yet emit SDK source files.

Build

cargo build --manifest-path crates/Cargo.toml -p nokturn-gen
cargo install --path ./crates/nokturn-gen

Usage

cargo run --manifest-path crates/Cargo.toml -p nokturn-gen -- \
  --log-level debug \
  generate \
  --schema open-api-specs/digitalocean/digitalocean.yaml \
  --config open-api-specs/digitalocean/config.toml \
  --output-dir generated/digitalocean
nokturn-gen generate --schema <schema-file> --output-dir <output-directory> --config <config-file>

You can also run the binary directly after a release build:

(cd crates && cargo build --release)
./crates/target/release/nokturn-gen --log-level info generate \
  --schema open-api-specs/digitalocean/digitalocean.yaml \
  --config open-api-specs/digitalocean/config.toml \
  --output-dir generated/digitalocean
nokturn-gen --log-level debug generate --schema openapi.yaml --config config.toml --output-dir ./output

Supported log levels: trace, debug, info, warn, error.

Configuration

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

crate_name = "digitalocean"
version = "0.1.0-alpha"
edition = "2024" # optional
description = "Unofficial Rust SDK for DigitalOcean"
lib_status = "experimental"
keywords = ["digitalocean"]
api_url = "https://api.digitalocean.com/v2"
authors = ["Cloudflavor GmbH <foss@cloudflavor.io>"]

# Optional filtering
include_only = ["User", "Account"]
exclude = ["InternalModel"]

In-tree examples live under open-api-specs/*/config.toml.

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

nokturn-gen 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.