Route files and matching

Tavo.js discovers route modules below src/pages. A normal page file contributes a URL; a special module changes how matching, layout, or failure rendering works. Route groups organize files and select layouts without adding a path segment.

textsrc/pages/
  index.tsx                    → /
  about.tsx                    → /about
  projects/
    _layout.tsx                → wraps project descendants
    index.tsx                  → /projects
    new.tsx                    → /projects/new
    [id].tsx                   → /projects/:id
    [[tab]].tsx                → /projects/:?tab
    [...path].tsx              → /projects/*path
  (account)/
    _layout.tsx                → selects a layout; no URL segment
    settings.tsx               → /settings
  404.tsx                      → unmatched and notFound() UI
  _error.tsx                  → fallback for page-loader errors

The default export renders the page. Named exports add behavior without changing the route path. defineRoutePage is optional route-aware typing; it does not register the route or override its filename. Its path literal is checked with RouteParamsFromPath, while the filesystem remains authoritative.

tsximport type {
  PageLoadContext,
  PageProps
} from "@tavojs/core/router";
import { Page, Text } from "@tavojs/ui";

type Project = { id: string; name: string };
type ProjectParams = { id: string };

export async function load({
  params,
  signal,
  url
}: PageLoadContext): Promise<Project> {
  const response = await fetch(
    new URL(`/api/projects/${params.id}`, url),
    { signal }
  );
  if (!response.ok) {
    throw new Error("Could not load project");
  }
  return response.json() as Promise<Project>;
}

export function head({ data }: { data: Project | null }) {
  return <title>{data ? data.name : "Project"}</title>;
}

export default function ProjectPage({
  data
}: PageProps<Project, ProjectParams>) {
  return (
    <Page>
      <Text as="h1" variant="h1">
        {data?.name}
      </Text>
    </Page>
  );
}

• Page modules may export load, action, middleware, head, pending, error, render, prerender, revalidate, vary, cacheTags, and generateStaticParams.

• Layout modules use the same data, middleware, head, and rendering exports and receive children from the route beneath them.

• Use defineRoutePage from @tavojs/core/router later when path-derived params and one object are clearer for a complex route.

• Keep the helper path literal aligned with the file path and inspect the generated manifest; the filesystem remains authoritative.

Matching is independent of filesystem discovery order. Tavo.js compares each segment from left to right and tries the more specific pattern first.

textstatic
  → required dynamic [id]
  → optional dynamic [[id]]
  → required catch-all [...path]
  → optional catch-all [[...path]]

/projects/new       wins over /projects/[id]
/docs/[version]     wins over /docs/[...path]
/files/[...path]    wins over /files/[[...path]]

When two compiled patterns have identical specificity, Tavo.js uses a lexical path tie-break. Treat equivalent patterns as a collision to fix, not as a way to choose behavior by declaration order.

• src/pages/404.tsx renders when no route matches and when a loader or middleware calls notFound(). The response status is 404.

• A page-local error export handles that page loader's failure and implements the PageErrorProps contract: pathname, params, route layers, page data, and the error.

• src/pages/_error.tsx is the fallback when a page loader fails and the page has no local error export.

• A layout receives its own loader error through its error prop. Descendant loaders still run unless the failure is notFound(), and page pending UI is skipped while a layout error exists.

• Files whose stem begins with an underscore are not public routes. Only documented special filenames receive special behavior.

tsximport { Page, Text } from "@tavojs/ui";

export default function NotFoundPage({
  pathname
}: {
  pathname?: string;
}) {
  return (
    <Page>
      <Text as="h1" variant="h1">
        Page not found
      </Text>
      <Text>The path {pathname ?? "you requested"} does not exist.</Text>
    </Page>
  );
}

Current Core source and tests recognize a top-level _root.tsx and a page-level layout = false export. Their final public 1.0 semantics are not yet ratified.

• _root.tsx currently wraps every matched route before directory layouts and uses the layer ID _root.

• layout = false currently skips directory _layout.tsx modules for that page while retaining _root.tsx.

• Do not make reusable application architecture depend on either convention until Core publishes its stable contract, inheritance rules, and migration guarantees.

• Use explicit directory layouts for production documentation and examples in the meantime.

bashnpx tavo routes
npx tavo inspect route /projects/new --json
npx tavo inspect route /projects/example --json
npx tavo check

Verify both the static and dynamic examples so precedence is observable. Also request an unknown path and a loader path that calls notFound() to confirm the same 404 module and status are used.