system prompt suspport

ai_client.py

@@ -48,6 +48,18 @@ _SYSTEM_PROMPT = (
     "need to re-read files that are already provided in the <context> block."
 )
 
+
+_custom_system_prompt: str = ""
+
+def set_custom_system_prompt(prompt: str):
+    global _custom_system_prompt
+    _custom_system_prompt = prompt
+
+def _get_combined_system_prompt() -> str:
+    if _custom_system_prompt.strip():
+        return f"{_SYSTEM_PROMPT}\n\n[USER SYSTEM PROMPT]\n{_custom_system_prompt}"
+    return _SYSTEM_PROMPT
+
 # ------------------------------------------------------------------ comms log
 
 _comms_log: list[dict] = []
@@ -403,7 +415,7 @@ def _send_gemini(md_content: str, user_message: str, base_dir: str, file_items:
             _gemini_chat = _gemini_client.chats.create(
                 model=_model,
                 config=types.GenerateContentConfig(
-                    system_instruction=_SYSTEM_PROMPT,
+                    system_instruction=_get_combined_system_prompt(),
                     tools=[_gemini_tool_declaration()]
                 )
             )
@@ -635,7 +647,7 @@ def _send_anthropic(md_content: str, user_message: str, base_dir: str, file_item
                 system=[
                     {
                         "type": "text",
-                        "text": _SYSTEM_PROMPT,
+                        "text": _get_combined_system_prompt(),
                         "cache_control": {"type": "ephemeral"},
                     }
                 ],