remix-run/remix · error · TypeError

hmr must be provided

Error message

hmr must be provided

What it means

`--verbose` adds extra decoration to the human-readable routes output and is incompatible with `--json`, which must stay machine-parseable. The parser rejects the pair at parse time.

Source

Thrown at packages/assets/src/lib/asset-server.ts:922

  let hmrBase = `${basePath}/__remix_hmr`
  return {
    client: `${hmrBase}/client.js`,
    events: `${hmrBase}/events`,
  }
}

function createHmrClientResponse(eventPathname: string, method: string): Response {
  return new Response(method === 'HEAD' ? null : createHmrClientSource({ eventPathname }), {
    headers: {
      'Cache-Control': 'no-cache',
      'Content-Type': 'application/javascript; charset=utf-8',
    },
  })
}

function assertBrowserEventUrl(url: string | undefined): asserts url is string {
  if (url === undefined) {
    throw new TypeError('hmr must be provided')
  }
}

function createHmrPayloadSender(): (payload: HmrPayload) => void {
  return () => {}
}

function createBrowserHmrEvent(
  payload: Extract<HmrPayload, { type: 'browser:reload' | 'browser:update' }>,
  files: readonly string[],
): BrowserHmrEvent {
  if (payload.type === 'browser:reload') {
    return {
      ...(files.length === 0 ? {} : { files: [...files] }),
      type: 'reload',
    }
  }

View on GitHub (pinned to 9696913134)

Solutions

1. Drop `--verbose` when using `--json`
2. If you need more data in JSON, the JSON output already includes full route info — parse it directly
3. Remove stale flags from shared scripts

Example fix

# before
remix routes --json --verbose
# after
remix routes --json

let args = ['remix','routes'];
if (json) args.push('--json');
else if (verbose) args.push('--verbose'); // mutually exclusive by construction

function isValidRoutesFlags(f: { json?: boolean; verbose?: boolean }): boolean {
  return !(f.json && f.verbose);
}

When it happens

Trigger: Running `remix routes --json --verbose` — both flags truthy in `parseRoutesCommandArgs`.

Common situations: Scripts that used `--verbose` and later gained `--json`; wanting extra detail in JSON output and assuming verbose applies.

Related errors

• hmr requires watch mode
• Missing app/routes.ts path.
• Route module ${routesFile} must export a named "routes" valu
• RMX_ROUTE_MAP_LOADER_FAILED
• RMX_ROUTE_MAP_LOADER_INVALID_JSON

AI-assisted analysis of remix-run/remix@9696913134 (2026-08-27). Data as JSON: /api/errors/9331af00d7200c4c. Report an issue: GitHub.