Orchestrator

A runtime micro-frontend orchestrator that loads Native Federation remotes into any web page, with advanced dependency resolution and cross-reload caching.

The Orchestrator — @softarc/native-federation-orchestrator — is the next-generation browser runtime for Native Federation. It replaces the classic Runtime (@softarc/native-federation-runtime) as the way to load remotes on the host, whether the host is a SPA, a plain HTML page, or a server-rendered application (PHP, Rails, Java, …).

What makes it different

Compared to the classic runtime, the orchestrator adds five things:

• Semver-aware version resolution. When remotes disagree on a shared dependency version, the orchestrator picks the most compatible version per share-scope and falls back to scoped downloads only when it has to. See Version Resolver.
• Cross-reload caching. Resolved remoteEntry.json metadata and shared externals can be persisted in sessionStorage or localStorage, so server-rendered hosts that refresh on every navigation don't re-download what the browser already has.
• A zero-setup quickstart bundle. For HTML-only hosts, a single <script> tag reads a manifest out of the DOM and wires everything up — no npm install, no build step.
• Built-in Trusted Types & SRI. The two DOM sinks (the injected <script type="importmap"> and the dynamic import()) flow through a vetted Trusted Types policy, and every artifact the orchestrator touches — the manifest, every remoteEntry.json, every JavaScript module — can be pinned against an SRI hash. See Security.
• Server-side orchestration. The same pipeline runs in Node through @softarc/native-federation-orchestrator/node, so SSR / edge-render hosts use the same version resolver, SRI verification and dynamic-init flow as the browser. See Node.js / SSR.

The orchestrator stays fully compatible with the Native Federation ecosystem — any remote built with @softarc/native-federation (v3 or v4) that emits a standard remoteEntry.json can be loaded by it.

SSR

On v4 the Orchestrator runs server-side too, so remote modules execute during SSR itself — not just client-side after the page arrives. The /node entry installs a module.register() loader hook and bridges the host's shared singletons (hostInstances) so a remote's @angular/core resolves to the host's single instance. For Angular, the adapter's node-preload wires this for you — see Angular Adapter → SSR & Hydration. For the general picture see SSR & Hydration.

In this section

• Getting Started — the quickstart bundle, the event registry, and writing your own orchestrator script.
• Architecture — the manifest, remoteEntry.json, the internal caches, and how the final import map is built.
• Configuration — the full initFederation options reference: host entry, import-map implementation, logging, modes and storage.
• Version Resolver — how shared dependencies are resolved across scopes, the shareScope mechanism, the strict scope, and dynamic init.
• Dependency Pooling — the opt-in feature that keeps a coupled package family (@angular/*, react/react-dom, your own design system) from being assembled out of builds that never shipped together.
• Event Registry — the window.__NF_REGISTRY__ event bus: race-free init, cross-MFE resources, and event streams.
• Node.js / SSR — initNodeFederation, the module.register() loader hook, and migration from @softarc/native-federation-node.
• Module Federation — createGetShared, the bridge that hands Native Federation's resolved singletons to webpack Module Federation's shared config.
• Security & Subresource Integrity — CSP setup for the built-in Trusted Types policy and the SRI trust chain (manifest → remoteEntry.json → modules).

Legacy Runtime

The classic runtime — @softarc/native-federation-runtime — was Native Federation's original browser runtime: one version of each shared dependency per scope, no semver resolution, no persistent caching. It shipped through v3 and v4 (up to 4.1.2) and is now deprecated and end-of-life on npm, with the Orchestrator named as its replacement. Existing installs keep working — same remoteEntry.json contract — but there will be no further fixes or features.

Its API pages live in the v3 docs rather than here: they document an initFederation / loadRemoteModule pair close enough to the Orchestrator's to be mistaken for it. Legacy Runtime is what remains in this tree — a summary of the gaps that motivated the Orchestrator. To move off, see Migration to v4 and v3 vs v4.

Example repositories

• Vanilla JS/HTML host — the orchestrator inside a plain HTML page.
• Angular host (v3) — the orchestrator inside an Angular monorepo using Native Federation v3.
• Angular host (v4) — same, using Native Federation v4.