Hmbown/CodeWhale · error · ServerError

foreground_denied

foreground_denied

Error message

the user denied shared-desktop (foreground) control on this computer — continue with open_application activate:false (background control) or ask them to reconsider.

What it means

Thrown by consentCheck() when open_application is called with activate:true but the user has recorded a deny decision for shared-desktop (foreground) control. Taking the shared pointer/focus is a second, separate consent from per-app access on every platform. The error offers the supported alternative: background control with activate:false, or asking the user to reconsider.

Solutions

1. Re-call open_application with activate:false for background control.
2. Ask the user to reconsider; if they agree, record it with consent {action:"allow", scope:"foreground"}.
3. If the deny was persisted by mistake, revoke it with consent {action:"revoke", scope:"foreground"}.

Example fix

// before
await callTool({ name: "open_application", arguments: { name: "Firefox", activate: true } }); // throws foreground_denied

// after: background control needs no foreground consent
await callTool({ name: "open_application", arguments: { name: "Firefox", activate: false } });

try {
  return await callTool({ name: "open_application", arguments: { ...args, activate: true } });
} catch (e) {
  if (e.code === "foreground_denied") {
    // fall back to background control, which requires no foreground consent
    return await callTool({ name: "open_application", arguments: { ...args, activate: false } });
  }
  throw e;
}

When it happens

Trigger: open_application with args.activate === true while consent.foregroundDecision(computer.id).state === "denied".

Common situations: User denied foreground control earlier in the session or via a persisted decision; an agent habitually passes activate:true and hits the deny on every launch attempt.

Understand the failure class

Background: Permission denied / not authorized / 403 Forbidden: access-control rejections when the caller lacks the required role, grant, or ownership — this error's family across 18 libraries.

Related errors

• app_denied
• consent_required
• foreground_consent_required
• computer_observation_required
• control_stopped

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/fd893e06e6be24e8. Report an issue: GitHub.

Appendix: source

Thrown at crates/tui/plugins/computer-use/mcp/server.mjs:596

    if (verdict.state === "denied") {
      throw new ServerError("app_denied",
        `the user denied access to ${desc} on this computer — do not work around it; only they can change it (consent {action:"revoke"}).`,
        { app: known });
    }
    if (verdict.state === "undecided") {
      throw new ServerError("consent_required",
        `Codewhale needs the user's permission to use ${desc} on this computer — ask them, then record their answer with consent {action:"allow"|"deny", app:"${arg}"}.`,
        { app: known });
    }
    grant = { ref: known, persisted: verdict.persisted === true };
  }
  // Taking the shared pointer/focus is a second, separate consent: the first
  // activate:true is the moment the agent stops being background — on every
  // platform, not just macOS.
  if (name === "open_application" && args.activate === true) {
    const fg = consent.foregroundDecision(computer.id);
    if (fg.state === "denied") {
      throw new ServerError("foreground_denied",
        `the user denied shared-desktop (foreground) control on this computer — continue with open_application activate:false (background control) or ask them to reconsider.`,
        { scope: "foreground" });
    }
    if (fg.state === "undecided") {
      throw new ServerError("foreground_consent_required",
        `open_application activate:true would take this computer's shared pointer and focus — ask the user, then record their answer with consent {action:"allow"|"deny", scope:"foreground"}. Background control (activate:false) needs no such consent.`,
        { scope: "foreground" });
    }
  }
  return grant ? { grant } : null;
}

// ---------- tool dispatch ----------
async function callTool(params) {
  const requested = params.name;
  if (!TOOL_NAMES.has(requested)) {
    return { content: [{ type: "text", text: JSON.stringify({ ok: false, error: { code: "unknown_tool", message: `unknown tool "${requested}"` } }) }], isError: true };
  }

View on GitHub (pinned to 73e0f67d83)