fibrae

Imported from DanielFGray/fibrae (AGENTS.md). Install upstream with npx skills add DanielFGray/fibrae. Copyright stays with the author.

fibrae

Effect-native JSX browser renderer with SSR, SSG, routing, live SSE sync, and automatic reactivity.

Branches

• develop — default branch, day-to-day development
• main — release branch (merge develop → main triggers release-please → npm publish)
• smol — v4 rewrite (Effect 4.0.0-beta.8, uses effect/unstable/reactivity)

Commands

bun run build         # TypeScript compile (packages/fibrae)
bun run types:check   # Type check all workspaces
oxlint                # Lint
cd packages/demo && bun cypress:run  # E2E tests

Style

Write idiomatic Effect code. See AGENTS.md for full coding guidelines.

• FP patterns: map/reduce/pipe, not imperative loops
• Effect stdlib: forEach, all, reduce, iterate, Mailbox, RcMap — don't reinvent
• Atom APIs: prefer Atom.get/set/update (Effect-based) over manual registry access
• Schema.TaggedError for all errors — never Data.TaggedError, never throw new Error
• Schema.decodeUnknown (Effect-returning) — never sync decode variants
• Pipe style, no console.log, minimize as casts — fix inference rather than casting
• Casts belong at type-erasure boundaries in the library, never in consumer code

Key Patterns

• JSX uses classic transform with jsxInject for fibrae/jsx-runtime
• JSX event handlers accept both onClick and onclick, can return Effects
• Layer.fresh() prevents Layer memoization sharing state across render() calls
• resubscribeFiber() closes alternate's componentScope to prevent subscription leaks
• Event handlers can return Effects — forked with full app context via runForkWithRuntime
• Components return VElement | Effect<VElement> | Stream<VElement>
• Fiber.componentScope is Scope.Closeable (not just Scope)
• FiberRef.currentContext returns Context<never> — store and pass as Context<never>
• Link uses real paths: <Link href="/posts/42"> — type-safe via RegisteredRouter + PatternToHref
• Router/RouteGroup accumulate route paths as literal types — <Link href="/typo"> is a type error
• RouterBuilder.group() takes RouteGroup directly (not string name) for type-safe handle()
• Route.match/interpolate return Effects — RouteError for failures
• RouteHandler stores Effects with R=never (type erasure boundary in handle())