feat: add token budget tracking and enforcement

- Add max_budget and on_budget_exceeded to ExecutionConfig
- Track total cost, tokens, and LLM calls per agent run
- Enforce budget limits with stop/warn/callable actions
- Zero overhead when budget tracking is disabled
- Add BudgetExceededError exception
- Update config serialization to include budget fields

Provides cost control for agent deployments with configurable limits.

src/praisonai-agents/patch_loader_and_agent.py

@@ -0,0 +1,148 @@
+import re
+
+# 1. Update config/loader.py to compute is_empty once
+with open("praisonaiagents/config/loader.py", "r") as f:
+    loader_code = f.read()
+
+# Replace the @property is_empty with just a cached boolean mechanism
+old_prop = """    @property
+    def is_empty(self) -> bool:
+        \"\"\"Return True if all features are empty/default.\"\"\"
+        return (
+            self.model is None and
+            self.base_url is None and
+            self.allow_delegation is False and
+            self.allow_code_execution is False and
+            self.code_execution_mode == "safe" and
+            self.memory is None and
+            self.knowledge is None and
+            self.planning is None and
+            self.reflection is None and
+            self.web is None and
+            self.output is None and
+            self.execution is None and
+            self.caching is None and
+            self.autonomy is None and
+            self.skills is None
+        )"""
+
+new_prop = """    _is_empty: Optional[bool] = None
+
+    @property
+    def is_empty(self) -> bool:
+        \"\"\"Return True if all features are empty/default.\"\"\"
+        if self._is_empty is not None:
+            return self._is_empty
+            
+        self._is_empty = (
+            self.model is None and
+            self.base_url is None and
+            self.allow_delegation is False and
+            self.allow_code_execution is False and
+            self.code_execution_mode == "safe" and
+            self.memory is None and
+            self.knowledge is None and
+            self.planning is None and
+            self.reflection is None and
+            self.web is None and
+            self.output is None and
+            self.execution is None and
+            self.caching is None and
+            self.autonomy is None and
+            self.skills is None
+        )
+        return self._is_empty"""
+
+loader_code = loader_code.replace(old_prop, new_prop)
+with open("praisonaiagents/config/loader.py", "w") as f:
+    f.write(loader_code)
+
+
+# 2. Update agent/agent.py to use _defaults
+with open("praisonaiagents/agent/agent.py", "r") as f:
+    agent_code = f.read()
+
+old_llm_block = """        # Apply config defaults for LLM if not explicitly set
+        if llm is None and model is None:
+            config_model = get_default("model")
+            if config_model:
+                llm = config_model
+        
+        # Apply config defaults for base_url if not explicitly set
+        if base_url is None:
+            config_base_url = get_default("base_url")
+            if config_base_url:
+                base_url = config_base_url"""
+
+new_llm_block = """        # Delay config loading to avoid _loader_get_defaults unless needed"""
+
+# Actually we need _defaults ANYWAY for the rest of features, so let's just initialize _defaults FIRST!
+
+old_everything = """        from ..config.loader import apply_config_defaults, get_default
+        
+        # Apply config defaults for LLM if not explicitly set
+        if llm is None and model is None:
+            config_model = get_default("model")
+            if config_model:
+                llm = config_model
+        
+        # Apply config defaults for base_url if not explicitly set
+        if base_url is None:
+            config_base_url = get_default("base_url")
+            if config_base_url:
+                base_url = config_base_url
+        
+        # Apply config defaults for feature params (memory, knowledge, etc.)
+        from ..config.loader import get_defaults_config as _loader_get_defaults"""
+
+new_everything = """        from ..config.loader import get_defaults_config as _loader_get_defaults
+        global _CACHED_DEFAULTS
+        if _CACHED_DEFAULTS is None:
+            _CACHED_DEFAULTS = _loader_get_defaults()
+        _defaults = _CACHED_DEFAULTS
+        _defaults_empty = _defaults.is_empty if hasattr(_defaults, 'is_empty') else False
+
+        # Apply config defaults for LLM if not explicitly set
+        if llm is None and model is None and _defaults.model:
+            llm = _defaults.model
+            
+        # Apply config defaults for base_url if not explicitly set
+        if base_url is None and _defaults.base_url:
+            base_url = _defaults.base_url
+
+        # Note: We already set __CACHED_DEFAULTS above, so no need here"""
+
+agent_code = agent_code.replace(old_everything, new_everything)
+
+old_redundant = """        from ..config.loader import get_defaults_config as _loader_get_defaults
+        global _CACHED_DEFAULTS
+        if _CACHED_DEFAULTS is None:
+            _CACHED_DEFAULTS = _loader_get_defaults()
+        _defaults = _CACHED_DEFAULTS
+        _defaults_empty = _defaults.is_empty if hasattr(_defaults, 'is_empty') else False
+
+        if not _defaults_empty:"""
+new_redundant = """        if not _defaults_empty:"""
+
+# Just replace the second occurrence manually (or find it):
+if "        from ..config.loader import get_defaults_config as _loader_get_defaults" in agent_code[agent_code.find("if not _defaults_empty:") - 400 : agent_code.find("if not _defaults_empty:")]:
+    # It exists! We just drop the duplicate initialization
+    pass
+
+# A cleaner way using regex:
+agent_code = re.sub(
+    r"        from \.\.config\.loader import get_defaults_config as _loader_get_defaults\n"
+    r"        global _CACHED_DEFAULTS\n"
+    r"        if _CACHED_DEFAULTS is None:\n"
+    r"            _CACHED_DEFAULTS = _loader_get_defaults\(\)\n"
+    r"        _defaults = _CACHED_DEFAULTS\n"
+    r"        _defaults_empty = _defaults\.is_empty if hasattr\(_defaults, 'is_empty'\) else False\n\n"
+    r"        if not _defaults_empty:",
+    "        if not _defaults_empty:",
+    agent_code
+)
+
+with open("praisonaiagents/agent/agent.py", "w") as f:
+    f.write(agent_code)
+
+print("success!")

src/praisonai-agents/praisonaiagents/config/feature_configs.py

@@ -723,7 +723,7 @@ class ExecutionConfig:
 
     # Action when budget exceeded: "stop" (default) raises BudgetExceededError,
     # "warn" logs warning but continues, or callable(total_cost, max_budget).
-    on_budget_exceeded: Any = "stop"
+    on_budget_exceeded: Union[str, Callable, None] = "stop"
 
     def to_dict(self) -> Dict[str, Any]:
         """Convert to dictionary."""
@@ -738,6 +738,7 @@ class ExecutionConfig:
             "context_compaction": self.context_compaction,
             "max_context_tokens": self.max_context_tokens,
             "max_budget": self.max_budget,
+            "on_budget_exceeded": self.on_budget_exceeded,
         }