Installation

Thoth.Json is split into a core package holding the API, and one package per runtime.

Core

Thoth.Json.Core contains Decode, Encode, Codec and the computation expressions. It doesn't read or write JSON on its own.

dotnet add package Thoth.Json.Core

Runtime

Add the package matching the runtime your code targets. It supplies Decode.fromString and Encode.toString.

dotnet add package Thoth.Json.JavaScript

A project can reference more than one runtime package. This is what an isomorphic application does: the Fable code opens Thoth.Json.JavaScript, the server code opens one of the .NET packages, and both use the same coders.

Auto API

Thoth.Json.Core.Auto generates coders from your F# types using reflection. It's a separate package because reflection has a cost on bundle size.

dotnet add package Thoth.Json.Core.Auto

Sharing code between Fable and .NET

Coders are written against Thoth.Json.Core, which compiles everywhere. Only the runtime package differs, so a compiler directive is needed for its open alone.

open Thoth.Json.Core

#if FABLE_COMPILER_JAVASCRIPT
open Thoth.Json.JavaScript
#endif

#if FABLE_COMPILER_PYTHON
open Thoth.Json.Python
#endif

#if !FABLE_COMPILER
open Thoth.Json.Newtonsoft
#endif

// Here you can write your code as usual

Migrating from Thoth.Json 10 and Thoth.Json.Net

Thoth.Json and Thoth.Json.Net are the previous generation of the library. Their documentation lives under the Legacy version, in the picker at the top of this page.

The API is the same in spirit. The differences you'll meet when moving over:

• Thoth.Json and Thoth.Json.Net become Thoth.Json.Core plus a runtime package.
• Decoder<'T> is an interface instead of a function. A decoder written as fun path value -> ... becomes an object expression, see Override defaults.
• An encoder returns IEncodable instead of JsonValue.
• Extra moves to Thoth.Json.Core.Auto.