What causes "Auth isn't set" in cube-js/cube?

Call setAuth(validLivePreviewJwt) before startWatch().

Auth isn't set

Error message

Auth isn't set

What it means

LivePreviewWatcher.startWatch requires setAuth to have been called first; if this.auth is null it throws "Auth isn't set". The watcher cannot sync files to Cube Cloud without the deployment identity stored in the auth object.

Source

Thrown at packages/cubejs-backend-cloud/src/live-preview.ts:45

  public setAuth(token: string): AuthObject {
    try {
      const payload = JSON.parse(Buffer.from(token.split('.')[1], 'base64').toString());
      this.auth = {
        auth: token,
        deploymentId: payload.deploymentId,
        url: payload.url,
      };

      return this.auth;
    } catch (e: any) {
      internalExceptions(e);
      throw new Error('Live-preview token is invalid');
    }
  }

  public startWatch(): void {
    if (!this.auth) {
      throw new Error('Auth isn\'t set');
    }

    if (!this.watcher) {
      this.log('Start with Cube Cloud');
      this.watcher = chokidar.watch(
        process.cwd(),
        {
          ignoreInitial: false,
          ignored: [
            '**/node_modules/**',
            '**/.*'
          ]
        }
      );

      let preSaveTimeout: NodeJS.Timeout;
      this.watcher.on('all', (/* event, p */) => {
        if (preSaveTimeout) clearTimeout(preSaveTimeout);

View on GitHub (pinned to 7d981676b3)

Solutions

Call setAuth(validLivePreviewJwt) before startWatch().
Ensure the live-preview token is supplied through your startup flow (env var/config) so the auth step runs before watching begins.
If setAuth throws, fix the token first — startWatch will keep failing until auth is successfully set.
Order your boot code: create watcher → setAuth → startWatch.

Example fix

// before
const watcher = new LivePreviewWatcher();
watcher.startWatch(); // throws 'Auth isn't set'
// after
const watcher = new LivePreviewWatcher();
watcher.setAuth(process.env.CUBE_LIVE_PREVIEW_TOKEN!);
watcher.startWatch();

Defensive patterns

Strategy: validation

Validate before calling

if (!watcher['auth']) throw new Error('Call setAuth(token) before startWatch()');
// or expose/check via a wrapper that tracks auth state

Try / catch

try {
  watcher.startWatch();
} catch (e) {
  if (e instanceof Error && e.message === "Auth isn't set") {
    watcher.setAuth(process.env.CUBE_LIVE_PREVIEW_TOKEN!);
    watcher.startWatch();
  } else throw e;
}

Prevention

Enforce boot order: construct watcher → setAuth → startWatch.
Guard startup code to require the live-preview token env var when live preview mode is enabled.
Handle setAuth failure explicitly so startWatch is never called in an unauthenticated state.

When it happens

Trigger: Calling startWatch() on a freshly constructed LivePreviewWatcher without calling setAuth(token) beforehand, or after setAuth failed earlier and left this.auth unset.

Common situations: Running the dev server in live-preview mode without providing the live-preview token; providing an invalid token (see 'Live-preview token is invalid') so auth never gets set; a code path that starts watching before authentication completes.

Related errors

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/249ccd17f5ea93a4. Report an issue: GitHub.