Plugin module must export a function, default plugin, or plu

Error message

Plugin module must export a function, default plugin, or plugin object.

What it means

Error "Plugin module must export a function, default plugin, or plugin object." thrown in musistudio/claude-code-router.

Source

Thrown at packages/core/src/plugins/service.ts:1007

function isProtocolSpecifier(value: string): boolean {
  return /^[a-zA-Z][a-zA-Z0-9+.-]*:/.test(value);
}

function isPathInside(file: string, root: string): boolean {
  const relative = path.relative(root, file);
  return relative === "" || (Boolean(relative) && !relative.startsWith("..") && !path.isAbsolute(relative));
}

function normalizeLoadedPlugin(moduleValue: unknown): LoadedPlugin {
  const record = isRecord(moduleValue) ? moduleValue : {};
  const candidate = record.default ?? record.plugin ?? moduleValue;
  if (typeof candidate === "function") {
    return { setup: candidate as LoadedPlugin["setup"] };
  }
  if (isRecord(candidate)) {
    return candidate as LoadedPlugin;
  }
  throw new Error("Plugin module must export a function, default plugin, or plugin object.");
}

function matchProxyRoute(route: RegisteredProxyRoute, targetUrl: URL): string | undefined {
  if (!matchesHost(route.host, targetUrl.hostname)) {
    return undefined;
  }
  if (!route.paths?.length) {
    return "";
  }
  let matchedPathPrefix: string | undefined;
  for (const pathPrefix of route.paths) {
    const normalizedPathPrefix = normalizeRoutePath(pathPrefix) ?? "/";
    if (!matchesPathPrefix(normalizedPathPrefix, targetUrl.pathname)) {
      continue;
    }
    if (!matchedPathPrefix || normalizedPathPrefix.length > matchedPathPrefix.length) {
      matchedPathPrefix = normalizedPathPrefix;
    }

View on GitHub (pinned to 99f24806c6)

When it happens

Trigger: Thrown at packages/core/src/plugins/service.ts:1007 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of musistudio/claude-code-router@99f24806c6 (2026-08-27). Data as JSON: /api/errors/4b8273ab6383a564. Report an issue: GitHub.