Configure file must export configuration as default.

Error message

Configure file must export configuration as default.

What it means

Cube loaded the configuration module from memory (compiled/register-hooked source, e.g. from a TypeScript or embedded config) but it did not export the CreateOptions object as the default export. Cube only reads `exports.default` from in-memory configuration modules. This enforces the convention that config files use `export default`.

Source

Thrown at packages/cubejs-server/src/server/container.ts:331

    const script = new vm.Script(content);
    script.runInNewContext(
      {
        require,
        console,
        // Workaround for ES5 exports
        exports
      },
      {
        filename: 'cube.js',
        displayErrors: true,
      }
    );

    if (exports.default) {
      return exports.default;
    }

    throw new Error(
      'Configure file must export configuration as default.'
    );
  }

  protected async loadConfigurationFromPythonFile(): Promise<CreateOptions> {
    const content = await fsAsync.readFile(
      path.join(process.cwd(), 'cube.py'),
      'utf-8'
    );

    if (this.configuration.debug) {
      console.log('Loaded python configuration file', content);
    }

    return this.loadConfigurationFromPythonMemory(content);
  }

  protected async loadConfigurationFromPythonMemory(content: string): Promise<CreateOptions> {

View on GitHub (pinned to 7d981676b3)

Solutions

Change the config module to use a default export: `export default { ... }`
If using CommonJS, set `module.exports.default = { ... }` or `module.exports = { default: opts }`
Check the transpiler/interop settings (esModuleInterop / __esModule flag) so exports.default is populated
Verify the file being loaded is the intended config file

Example fix

// before
module.exports = {
  driverFactory: () => new PostgresDriver({}),
};

// after
export default {
  driverFactory: () => new PostgresDriver({}),
};

Defensive patterns

Strategy: validation

Validate before calling

// check before relying on in-memory config loading
const mod = require('./cube.ts-compiled');
if (!mod.default) {
  throw new Error('Config module must use export default');
}

Type guard

function hasDefaultExport(m: unknown): m is { default: Record<string, unknown> } {
  return typeof m === 'object' && m !== null && 'default' in m;
}

Try / catch

try {
  await server.listen();
} catch (e) {
  if (e.message === 'Configure file must export configuration as default.') {
    console.error('Add `export default { ... }` to your TypeScript config');
  }
  throw e;
}

Prevention

Always use `export default` in TypeScript config modules
Avoid mixing module.exports and export default in the same file
Enable esModuleInterop for consistent interop
Smoke-test config loading in CI before deploy

When it happens

Trigger: A cube.ts / config module compiled and loaded via loadConfigurationFromMemory that uses `module.exports = {...}` or named exports only (`export const cube = ...`) instead of `export default`.

Common situations: Porting an older CommonJS cube.js config to the TS pipeline without converting to default export; writing `exports.config = ...`; Babel/TS interop quirks where module.exports shape lacks `.default`.

Related errors

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/23a2b05c414b007e. Report an issue: GitHub.