diff --git a/news_responder_gui.py b/news_responder_gui.py
index fc368db..015836f 100644
--- a/news_responder_gui.py
+++ b/news_responder_gui.py
@@ -651,7 +651,8 @@ def connect_thread():
                         self.root.after(0, lambda: self.update_tech_status('ai', True))
 
                 except Exception as e:
-                    self.root.after(0, lambda: self.update_status(f"Warning: Could not load API keys: {e}", 50))
+                    # Python clears the exception binding before Tk runs this callback.
+                    self.root.after(0, lambda error=str(e): self.update_status(f"Warning: Could not load API keys: {error}", 50))
 
                 self.root.after(0, lambda: self.update_status("Loading Feedly RSS feed...", 60))
                 self.refresh_rss_feed()
@@ -679,9 +680,9 @@ def connect_thread():
                 self.root.after(0, lambda: self.connect_btn.configure(text="Reconnect", bg=self.colors['bg_input']))
 
             except Exception as e:
-                self.root.after(0, lambda: self.update_status(f"Connection failed: {str(e)}", 0))
+                self.root.after(0, lambda error=str(e): self.update_status(f"Connection failed: {error}", 0))
                 self.root.after(0, lambda: self.update_progress_title("Error"))
-                self.root.after(0, lambda: messagebox.showerror("Connection Error", str(e)))
+                self.root.after(0, lambda error=str(e): messagebox.showerror("Connection Error", error))
 
         threading.Thread(target=connect_thread, daemon=True).start()
 
@@ -824,8 +825,8 @@ def process_thread():
                 self.root.after(0, lambda: self.update_progress_title("Complete"))
 
             except Exception as e:
-                self.root.after(0, lambda: self.update_status(f"Error: {str(e)}", 0))
-                self.root.after(0, lambda: messagebox.showerror("Processing Error", str(e)))
+                self.root.after(0, lambda error=str(e): self.update_status(f"Error: {error}", 0))
+                self.root.after(0, lambda error=str(e): messagebox.showerror("Processing Error", error))
 
             finally:
                 self.is_processing = False
diff --git a/tests/test_gui_callbacks.py b/tests/test_gui_callbacks.py
new file mode 100644
index 0000000..3ee4470
--- /dev/null
+++ b/tests/test_gui_callbacks.py
@@ -0,0 +1,64 @@
+"""Run worker callbacks after the worker exits, without opening a GUI."""
+import ast
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import Mock
+
+import pytest
+
+
+def worker_method(name, **globals_override):
+    # Load just the worker method so headless CI needs neither Tcl nor a display.
+    source = Path(__file__).resolve().parents[1] / "news_responder_gui.py"
+    tree = ast.parse(source.read_text())
+    gui = next(node for node in tree.body if isinstance(node, ast.ClassDef))
+    method = next(node for node in gui.body if getattr(node, "name", None) == name)
+    namespace = {
+        "threading": SimpleNamespace(Thread=lambda target, **kw: SimpleNamespace(start=target)),
+        "GSPREAD_AVAILABLE": True,
+        "GOOGLE_CREDS_FILE": "unused.json",
+        "Credentials": Mock(),
+        "gspread": Mock(),
+        "messagebox": Mock(),
+    }
+    namespace.update(globals_override)
+    exec(compile(ast.Module(body=[method], type_ignores=[]), str(source), "exec"), namespace)
+    return namespace[name], namespace
+
+
+@pytest.mark.parametrize("method_name, error_title", [
+    ("connect_sheet", "Connection Error"),
+    ("start_processing", "Processing Error"),
+])
+def test_error_callbacks_survive_worker_exit(method_name, error_title):
+    method, namespace = worker_method(method_name)
+    callbacks = []
+    gui = Mock(is_processing=False)
+    gui.root.after.side_effect = lambda delay, callback: callbacks.append(callback)
+    namespace["Credentials"].from_service_account_file.side_effect = RuntimeError("service unavailable")
+    gui.sheet.get_all_values.side_effect = RuntimeError("service unavailable")
+
+    method(gui)
+    for callback in callbacks:
+        callback()
+
+    namespace["messagebox"].showerror.assert_called_once_with(error_title, "service unavailable")
+    assert any("service unavailable" in call.args[0] for call in gui.update_status.call_args_list)
+
+
+def test_api_key_warning_survives_worker_exit():
+    method, namespace = worker_method("connect_sheet", SHEET_ID="example", SHEET_NAME="Comments", COL_CHATGPT=14)
+    callbacks = []
+    gui = Mock(api_keys={}, colors={"bg_input": "#000000"})
+    gui.root.after.side_effect = lambda delay, callback: callbacks.append(callback)
+    spreadsheet = namespace["gspread"].authorize.return_value.open_by_key.return_value
+    sheet = Mock()
+    sheet.get_all_values.return_value = [["header"]]
+    spreadsheet.worksheet.side_effect = [sheet, RuntimeError("API tab missing")]
+
+    method(gui)
+    for callback in callbacks:
+        callback()
+
+    assert any("API tab missing" in call.args[0] for call in gui.update_status.call_args_list)
+    namespace["messagebox"].showerror.assert_not_called()