usebruno/bruno · error · Error

Mock server is a beta feature. Enable it in Preferences > Be

Error message

Mock server is a beta feature. Enable it in Preferences > Beta.

What it means

Error "Mock server is a beta feature. Enable it in Preferences > Beta." thrown in usebruno/bruno.

Source

Thrown at packages/bruno-electron/src/app/mock-server/mock-server.js:504

  }, 3000);

  httpServer.on('close', () => clearTimeout(forceCloseTimeout));
});

const start = async ({
  mockServerUid,
  serverName,
  sourceType = 'collection',
  collectionPath,
  collectionName,
  brunoConfig,
  specPath,
  workspacePath,
  port = DEFAULT_GATEWAY_PORT,
  globalDelay = 0
}) => {
  if (!preferencesUtil.isBetaFeatureEnabled('mock-server')) {
    throw new Error('Mock server is a beta feature. Enable it in Preferences > Beta.');
  }

  if (!mockServerUid) {
    throw new Error('Mock server id is required.');
  }

  if (collections.has(mockServerUid)) {
    await stop(mockServerUid);
  }

  const routeMap = buildRouteMapFromMockResponses({
    mockServerUid,
    sourceType,
    collectionPath,
    workspacePath
  });

  let resolvedPort = Number(port) || DEFAULT_GATEWAY_PORT;

View on GitHub (pinned to 9bdd81c7bd)

Solutions

1. Enable the mock server beta feature in Preferences > Beta, then retry.

When it happens

Trigger: Thrown at packages/bruno-electron/src/app/mock-server/mock-server.js:504 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of usebruno/bruno@9bdd81c7bd (2026-08-13). Data as JSON: /api/errors/d57477de90a7e362. Report an issue: GitHub.