fix: Replace shallow copy with deep copy in _build_messages()

- Added import copy to both agent.py and test file
- Changed prompt.copy() to copy.deepcopy(prompt) to prevent mutation of original objects
- Ensures nested dictionaries in multimodal prompts are not modified

This fixes the issue where modifying item["text"] would mutate the original prompt objects.

Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

Author: claude[bot]

src/praisonai-agents/praisonaiagents/agent/agent.py

@@ -1,6 +1,7 @@
 import os
 import time
 import json
+import copy
 import logging
 import asyncio
 from typing import List, Optional, Any, Dict, Union, Literal, TYPE_CHECKING, Callable, Tuple
@@ -868,8 +869,8 @@ def _build_messages(self, prompt, temperature=0.2, output_json=None, output_pyda
             if isinstance(prompt, str):
                 prompt = prompt + "\nReturn ONLY a valid JSON object. No other text or explanation."
             elif isinstance(prompt, list):
-                # Create a copy to avoid modifying the original
-                prompt = prompt.copy()
+                # Create a deep copy to avoid modifying the original
+                prompt = copy.deepcopy(prompt)
                 for item in prompt:
                     if item.get("type") == "text":
                         item["text"] = item["text"] + "\nReturn ONLY a valid JSON object. No other text or explanation."

src/praisonai/tests/unit/test_agent_refactor.py

@@ -5,6 +5,7 @@
 """
 
 import asyncio
+import copy
 import logging
 from typing import Dict, Any
 
@@ -66,8 +67,8 @@ def _build_messages(self, prompt, temperature=0.2, output_json=None, output_pyda
             if isinstance(prompt, str):
                 prompt = prompt + "\nReturn ONLY a valid JSON object. No other text or explanation."
             elif isinstance(prompt, list):
-                # Create a copy to avoid modifying the original
-                prompt = prompt.copy()
+                # Create a deep copy to avoid modifying the original
+                prompt = copy.deepcopy(prompt)
                 for item in prompt:
                     if item.get("type") == "text":
                         item["text"] = item["text"] + "\nReturn ONLY a valid JSON object. No other text or explanation."