Overview

Build reactive state for .NET: update a value, and the computations that depend on it update too.

• Signals hold values you can read and write.
• Memos derive values from tracked reads.
• Effects run when a value they read changes.

A taste

open Ranvier

let graph = new Graph ()

let doubled =
    graph.Run (fun () ->
        let count = createSignal 1
        let doubled = createMemo (fun _ -> count.Value * 2)
        createEffect (fun () -> printfn "doubled = %d" doubled.Value)
        count.Value <- 5
        doubled)

doubled = 2
doubled = 10

What you get

Targets

net10.0, net8.0 and netstandard2.1 and Fable (JavaScript).

Guide

• Installation: preview packages, supported targets and Native AOT.
• Getting started: a short walkthrough of a reactive graph.
• Graphs, Signals, Memos and Effects: the core primitives.
• Roots and owners, Cleanup, Untrack and Batch: lifetime and tracking controls.
• Editable values and Drafts: local edits over upstream state.
• Async and pending: in-flight values, async memos, boundaries, and threading.
• Testing async state: deterministic tests that decide when each flight lands.
• Blazor Server: one graph per circuit, with ThreadAffinity.Serialised.
• Collections: an overview linking to projections, lookups, selectors and collection views.
• Aggregates: totals, counts and folds over collection rows.
• Forms: records of reactive fields and batched resets.
• Tracing: why a node ran or did not run, where it was created, and the graph as it stands.
• Signal maps: how to read the live graph maps beneath the examples, and how to write one.
• Troubleshooting: each exception message and common symptom, with its cause and fix.
• Migrating from Elmish: an MVU model read through selector memos, one view at a time.
• C#: C# factories, XAML bindings and reactive commands.

Status