diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 0179967de..082b4f997 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -39,6 +39,11 @@ jobs:
           OPENAI_API_KEY: ""
           NOUS_API_KEY: ""
 
+      - name: Syntax guard
+        run: |
+          source .venv/bin/activate
+          python scripts/syntax_guard.py
+
       - name: Green-path E2E
         run: |
           source .venv/bin/activate
diff --git a/scripts/syntax_guard.py b/scripts/syntax_guard.py
new file mode 100755
index 000000000..7c41dc9b4
--- /dev/null
+++ b/scripts/syntax_guard.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+"""Syntax guard — compile all Python files to catch syntax errors before merge."""
+import py_compile
+import sys
+from pathlib import Path
+
+errors = []
+for p in Path(".").rglob("*.py"):
+    if ".venv" in p.parts or "__pycache__" in p.parts:
+        continue
+    try:
+        py_compile.compile(str(p), doraise=True)
+    except py_compile.PyCompileError as e:
+        errors.append(f"{p}: {e}")
+        print(f"SYNTAX ERROR: {p}: {e}", file=sys.stderr)
+
+if errors:
+    print(f"\n{len(errors)} file(s) with syntax errors", file=sys.stderr)
+    sys.exit(1)
+print("All Python files compile successfully")