windmill-labs/windmill · warning

Could not fetch schema to validate args: ${e.message}

Error message

Could not fetch schema to validate args: ${e.message}

What it means

In `wmill flow run`, the CLI fetches the flow's schema from the workspace to validate that all required args are supplied. If that schema fetch/validation fails for any reason other than a genuine 'Missing required' error, it warns and proceeds to run the flow without arg validation.

Source

Thrown at cli/src/commands/flow/flow.ts:443

  if (opts.silent) {
    log.setSilent(true);
  }
  const workspace = await resolveWorkspace(opts);
  await requireLogin(opts);

  const input = opts.data ? await resolve(opts.data) : {};

  // Validate required args against schema when no data provided
  if (!opts.data) {
    try {
      const flow = await wmill.getFlowByPath({
        workspace: workspace.workspaceId,
        path,
      });
      validateRequiredArgs(flow.schema as Record<string, unknown>);
    } catch (e: any) {
      if (e.message?.startsWith("Missing required")) throw e;
      log.warn(`Could not fetch schema to validate args: ${e.message}`);
    }
  }

  const id = await wmill.runFlowByPath({
    workspace: workspace.workspaceId,
    path,
    tag: opts.tag,
    requestBody: input,
  });

  // Build step label map from raw_flow if available
  const stepLabels = new Map<string, string>();
  try {
    const initialJob = await wmill.getJob({
      workspace: workspace.workspaceId,
      id,
    });
    const rawFlow = (initialJob as any).raw_flow;

View on GitHub (pinned to e474e8803c)

Solutions

1. Check backend reachability and credentials: `wmill workspace show` and a simple `wmill flow list`.
2. Verify the flow path exists in the workspace and is spelled correctly.
3. Provide all required args explicitly with `-e/--extra-args` or a value file so validation failure does not matter.
4. Re-authenticate: `wmill login` to refresh the token.

Example fix

// before: relies on server-side schema, fails silently offline
wmill flow run u/company/etl
// after: supply args explicitly so the run is correct even without validation
wmill flow run u/company/etl --extra-args '{"date":"2026-09-03"}'

// preflight: confirm the flow is fetchable before relying on schema validation
try { await wmill.getFlowByPath(path); console.log('flow reachable'); }
catch (e) { console.error('backend/path unreachable:', e.message); }

null

try {
  await wmill.runFlowByPath({ workspace, path, args });
} catch (e: any) {
  if (/Could not fetch schema|ECONNREFUSED|401|404/.test(e.message ?? '')) {
    // check `wmill workspace show`, then retry with explicit --extra-args
  }
  throw e;
}

When it happens

Trigger: Running `wmill flow run <path>` when the schema fetch fails: offline/unreachable backend, invalid or expired credentials, flow path not found, or a transient network error during `wmill.getFlowByPath`.

Common situations: VPN/proxy down or flaky network; workspace token expired; typos in the flow path so the schema 404s; backend temporarily unavailable in self-hosted setups; the flow was deleted after the command line was composed.

Related errors

• Dependency generation failed: ${queueResponse.status} ${queu
• Failed to poll dependencies job ${jobId}: ${e?.message ?? e}
• No response body for SSE stream
• Failed to poll flow dependencies job ${jobId}: ${e?.message
• Couldn't fetch resource types from hub ${hubBaseUrl}: ${(awa

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/975bae09b2b614df. Report an issue: GitHub.