Kona

A dotnet CLI tool to generate type-safe Fable clients from OpenAPI/Swagger services, specifically designed for SolidJS applications with native JS.Promise support.

Note: Kona is a fork of Hawaii by Zaid Ajaj. For server-side .NET/F# API clients, use Kiota (Microsoft's official tool) or Hawaii. Kona focuses exclusively on client-side Fable/SolidJS code generation with promise { } computation expressions and future createResource integration.

Key Features

Feature	Kona	Hawaii
Local YAML/YML schemas	✅	❌
Fable/SolidJS optimized	✅	❌
promise { } CE	✅	❌
Thoth.Fetch	✅	❌
Server-side .NET	❌	✅

Why Kona?

Kona generates API clients optimized for SolidJS:

• Local YAML schema support - Use local .yaml or .yml schema files directly (not supported in Hawaii)
• promise { } computation expressions - Works seamlessly with SolidJS createResource
• Thoth.Fetch - Native browser fetch API, returns JS.Promise<int * string>
• Fable-only - No .NET server-side bloat, focused on client-side excellence

Install

dotnet tool install -g kona

Configuration

Create a kona.json file:

{ "schema": "https://petstore3.swagger.io/api/v3/openapi.json", "output": "./output", "project": "PetStore" }

Using Local YAML Schemas

Kona supports local YAML/YML schema files—a feature not available in Hawaii:

{ "schema": "./schemas/api.yaml", "output": "./output", "project": "MyApi" }

Run:

kona --config ./kona.json

Configuration Options

Option	Type	Required	Description
schema	string	✅	URL or local path to OpenAPI/Swagger schema (.json, .yaml, .yml)
project	string	✅	Name of generated project
output	string	✅	Output directory
resolveReferences	boolean		Resolve external schema references (default: false)
emptyDefinitions	"ignore" | "free-form"		Handle empty type definitions (default: ignore)
overrideSchema	object		Override schema properties
filterTags	string[]		Filter operations by OpenAPI tags

Supported Schema Formats

Format	Local File	Remote URL
JSON (.json)	✅	✅
YAML (.yaml, .yml)	✅	✅

Note: OData schemas are not supported. Kona only supports OpenAPI/Swagger specifications.

Usage with SolidJS

open Fable.Core.JS open PetStore open PetStore.Types let client = PetStoreClient("https://petstore3.swagger.io/api/v3", []) // Works directly with SolidJS createResource! let fetchPets () : JS.Promise<Pet list> = client.findPetsByStatus("available") |> Promise.map (function | FindPetsByStatus.OK pets -> pets | _ -> []) // In your SolidJS component let [pets] = createResource(fetchPets)

Roadmap

• Generate createResource wrapper functions automatically
• Generate typed query/mutation hooks for SolidJS
• Optimistic updates support

Credits

Kona is built on Hawaii by Zaid Ajaj. All credit for the core OpenAPI parsing and type generation goes to Hawaii.

License

MIT