Dual audience

One definition, four surfaces

A page's default export is the view; named exports configure the other surfaces. .json auto-derives from the loader data, so you only write what you customize:

import type { RouteContext, Loaded } from "@junejs/core/route";

export const loader = (ctx: RouteContext<{ slug: string }>) => fetchPost(ctx.params.slug);

export default function Post(post: Loaded<typeof loader>) {  // GET /posts/x   → streamed HTML
  return <article>…</article>;
}

export const md = (post: Loaded<typeof loader>) => post.original;   // GET /posts/x.md → AUTHORED markdown
export const metadata = (post: Loaded<typeof loader>) => ({ title: post.title });
// GET /posts/x.json → the loader data, auto-derived (no export needed)

The view receives loader data as props, the same shape the other three projections take it (md(data), metadata(data), .json = data): one loader, four surfaces, each a pure function of the data — nothing to drift. Deep child components can reach the same data without prop-drilling via the escape-hatch hook useLoaderData<typeof loader>() (also catches the Remix muscle-memory).

The .md projection serves the file you wrote, byte-for-byte — frontmatter included. Most frameworks reconstruct markdown from rendered HTML; June serves the source, so there is nothing to drift. Actions are the capability surface — each defineAction() is an MCP tool at /mcp (and a browser WebMCP tool).

What agents discover automatically

  • /llms.txt — route map + the framework's canonical names
  • /sitemap.xml, /robots.txt, /.well-known/api-catalog
  • /mcp — your defineAction()s as MCP tools: one definition is a UI server action AND an MCP tool AND a browser WebMCP tool

Actions are one gate

defineAction({ id, description, input, run }) — run(input, ctx) receives the same context (user, session, resources) whether the caller is your UI or an agent at /mcp. One authorization model, two kinds of callers.

The posture

Human-intent optimizations (Speculation-Rules prerender, View Transitions) apply to the HTML surface only; agent surfaces stay deliberately plain. Machines don't need view transitions.