RMT Node SSR Adapter

Server-side light DOM and hydration payloads for Node hosts.

What it covers

The Node SSR adapter renders RMT core records on the server and returns a hydration envelope for the browser. It owns no browser DOM and may therefore emit serializable, policy-checked output only.

Public building blocks

xtendrmt/rmt-node-ssr-adapter.js implements rendering and streaming.
xtendrmt/rmt-node-ssr-adapter.d.ts describes the public adapter API.
rmt-node-ssr-adapter checks envelopes, CSP, hydration, and JSONL streaming.

.rmt sources.
Core records and source maps.
Host adapters for DOM, routing and components.
Adapter contract xtend.rmt.node-ssr-adapter.v1.
JSONL streaming frames with xtend.rmt.node-ssr-jsonl-frame.v1.

Hydration Response Envelope

render().response uses rmt_template_prerender_response with executionMode: "server_prerender_hydrate". The response carries chunk, chunks, request, metadata.adapterKind: "node-ssr" and hydrate_existing target metadata so the client runtime can process it through hydrateResponse or degrade in a controlled way when diagnostics block the render.

Hydration Policies explains the choice between regular SSR hydration, deferred hydration, and a full resume handoff with RMT examples.

Automatic CSP

The adapter creates a framework-managed xtend.rmt.ssr-csp-policy.v1 policy for every render. render().headers, render().response.headers, hydration metadata, JSONL start frames and toHttpResponse() include Content-Security-Policy automatically, so hosts do not need separate CSP plumbing for the default SSR path.

Example

import { createRmtNodeSsrAdapter } from '@ccslabs/xtend/rmt/node-ssr-adapter';

const adapter = createRmtNodeSsrAdapter({ manifest, sourceTexts });
const result = await adapter.render({ source, filePath: 'app.rmt' });

Recommended workflow

Pass normalized core records, validate response status, and send markup, resume data, and CSP metadata together. On a policy diagnostic, return an error report rather than unsafe replacement HTML.

If your backend uses PHP or Laravel, use the same core output with the RMT PHP/Laravel SSR Adapter. Both adapters share the JSONL frame shape for incremental SSR output.

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