antigravity: permission responses are only available in defa

Error message

antigravity: permission responses are only available in default mode

What it means

RespondPermission returns this error when the session was created without a permission bridge — i.e. not in default (interactive permission) mode. In 'yolo' (permissions skipped) or 'plan' (sandbox) modes there is no TCP bridge wired up, so permission decisions have nothing to be relayed to.

Source

Thrown at agent/antigravity/session.go:393

	}
	if len(candidates) == 0 {
		return ""
	}
	sort.Slice(candidates, func(i, j int) bool {
		if candidates[i].diff == candidates[j].diff {
			return candidates[i].modTime.After(candidates[j].modTime)
		}
		return candidates[i].diff < candidates[j].diff
	})
	return candidates[0].sessionID
}

func (as *antigravitySession) RespondPermission(requestID string, result core.PermissionResult) error {
	if !as.alive.Load() {
		return fmt.Errorf("session is closed")
	}
	if as.permissionBridge == nil {
		return fmt.Errorf("antigravity: permission responses are only available in default mode")
	}
	return as.permissionBridge.RespondPermission(requestID, result)
}

func (as *antigravitySession) Events() <-chan core.Event {
	return as.events
}

func (as *antigravitySession) CurrentSessionID() string {
	v, _ := as.chatID.Load().(string)
	return v
}

func (as *antigravitySession) Alive() bool {
	return as.alive.Load()
}

func (as *antigravitySession) Close() error {

View on GitHub (pinned to 4000b2338a)

Solutions

Switch the agent mode to default in config.toml so the permission bridge is created
Suppress/hide permission-request UI for yolo/plan mode sessions before calling RespondPermission
Gate the call: only invoke RespondPermission if the session advertises permission support

Example fix

// before
return as.RespondPermission(requestID, result)
// after
if agentMode == "yolo" || agentMode == "plan" {
    return errors.New("permissions not available in this mode")
}
return as.RespondPermission(requestID, result)

Defensive patterns

Strategy: validation

Validate before calling

func permissionsSupported(mode string) bool { return mode == "" || mode == "default" }
if !permissionsSupported(cfg.Mode) { hidePermissionUI() }

Try / catch

if err := s.RespondPermission(id, res); err != nil && strings.Contains(err.Error(), "only available in default mode") {
    log.Warn("auto-denying: mode has no permission bridge")
}

Prevention

Only render permission UI for default-mode antigravity sessions
Document that yolo/plan modes cannot answer permission requests
Centralize mode checks where permission events are handled

When it happens

Trigger: Calling RespondPermission on a session whose permissionBridge field is nil, which happens when the agent was configured with mode="yolo" or mode="plan" instead of default mode.

Common situations: Config sets mode="yolo" to skip prompts, but platform UI still renders permission buttons that call RespondPermission; code assumes all antigravity sessions support interactive permissions.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/ba1bd6938c0d9e79. Report an issue: GitHub.