# fsbolero/Bolero

Bolero brings Blazor to F# developers with an easy to use Model-View-Update architecture, HTML combinators, hot reloaded templates, type-safe endpoints, advanced routing and remoting capabilities, and more.

Repository: https://github.com/fsbolero/Bolero
Canonical: https://ross.abutalabs.com/products/bolero
Homepage: https://fsbolero.io
Language: F#
License: Apache-2.0
License Family: permissive
Topics: bolero, blazor, fsharp, webassembly
Last push: 2026-08-21T15:44:45+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 98, longevity 100
- inputs: {"age_days": 2899, "days_push": 12, "days_rel": 12, "gap_med": 20, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1130, forks 59 (observed 2026-08-28T04:03:42.383900+00:00)

## What it is
Bolero is a set of F# libraries and tools for building web applications on top of Blazor, running in WebAssembly or server-side via SignalR. It provides an Elmish Model-View-Update architecture, HTML-in-F# combinators, type-provided HTML templates with hot reloading, union-type URL routing, and type-safe server remoting.

## Use cases
- build single-page web apps in F# without writing JavaScript
- use Elmish MVU architecture with Blazor components
- write HTML templates in separate files with hot reloading
- define type-safe URL routing with F# union types
- call ASP.NET Core server functions from the client as async calls
- reduce WebAssembly app download size by stripping F# metadata

## When to choose
- your team prefers F# and functional programming for client-side web development
- you want a strongly-typed alternative to JavaScript/TypeScript SPAs on .NET
- you already use Blazor and want Elmish MVU structure and F#-idiomatic HTML

## When to avoid
- your project is JavaScript/TypeScript-first or uses React/Vue ecosystems
- you need a large ecosystem of ready-made UI component libraries
- your team has no F# experience and cannot invest in learning it

## Facets
- artifact type: framework
- maturity: active
- function: frontend-framework, routing, templating, rpc, wasm
- domain: web-development, frontend, programming-languages, cross-platform
- platform: dotnet, browser, wasm, cross-platform
- tags: fsharp, blazor, elmish, model-view-update, webassembly, spa, type-provider, hot-reload, html-combinators, server-remoting, web-server

## Member repositories
- fsbolero/Bolero (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:42.383900+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:38:14.876165+00:00, confidence not recorded.
  - readme: https://github.com/fsbolero/Bolero (fetched 2026-08-28T04:03:42.383900+00:00, sha cb649e584df2)
  - homepage: https://fsbolero.io (fetched 2026-08-29T12:42:44.923321+00:00, sha bc1dcba1cede)
  - site_page: https://fsbolero.io/docs (fetched 2026-08-29T12:42:44.932390+00:00, sha 996342d47533)
  - site_page: https://fsbolero.io/docs/Hosting (fetched 2026-08-29T12:42:44.934388+00:00, sha 6a04348c6951)
  - site_page: https://fsbolero.io/docs/Hosting-pre-blazor-8 (fetched 2026-08-29T12:42:44.936151+00:00, sha 443ff7865893)
  - site_page: https://fsbolero.io/docs/HTML (fetched 2026-08-29T12:42:44.938028+00:00, sha a1191c5514d7)
  - site_page: https://fsbolero.io/docs/HTML-list-functions (fetched 2026-08-29T12:42:44.939815+00:00, sha e4980929bedd)
  - site_page: https://fsbolero.io/docs/Templating (fetched 2026-08-29T12:42:44.941590+00:00, sha db5dc72be6ad)
  - site_page: https://fsbolero.io/docs/Elmish (fetched 2026-08-29T12:42:44.943271+00:00, sha a15e90cdc490)
  - site_page: https://fsbolero.io/docs/Routing (fetched 2026-08-29T12:42:44.945650+00:00, sha 67a75ce553a5)
- Data as of 2026-08-30T08:39:29.467469+00:00.