Fix :This PR can resolve the issue of exceeding the default tool invocation limit by setting the recursion limit through an environment variable.mit (#138)

* set ecursion limit

* set ecursion limit

* fix:check if the recession_limit within a reasonalbe range

* style: format code with black

.env.example

@@ -5,6 +5,8 @@ APP_ENV=development
 # docker build args
 NEXT_PUBLIC_API_URL="http://localhost:8000/api"
 
+AGENT_RECURSION_LIMIT=30
+
 # Search Engine, Supported values: tavily (recommended), duckduckgo, brave_search, arxiv
 SEARCH_API=tavily
 TAVILY_API_KEY=tvly-xxx

src/graph/nodes.py

@@ -3,6 +3,7 @@
 
 import json
 import logging
+import os
 from typing import Annotated, Literal
 
 from langchain_core.messages import AIMessage, HumanMessage
@@ -350,7 +351,31 @@ async def _execute_agent_step(
         )
 
     # Invoke the agent
-    result = await agent.ainvoke(input=agent_input)
+    default_recursion_limit = 25
+    try:
+        env_value_str = os.getenv("AGENT_RECURSION_LIMIT", str(default_recursion_limit))
+        parsed_limit = int(env_value_str)
+
+        if parsed_limit > 0:
+            recursion_limit = parsed_limit
+            logger.info(f"Recursion limit set to: {recursion_limit}")
+        else:
+            logger.warning(
+                f"AGENT_RECURSION_LIMIT value '{env_value_str}' (parsed as {parsed_limit}) is not positive. "
+                f"Using default value {default_recursion_limit}."
+            )
+            recursion_limit = default_recursion_limit
+    except ValueError:
+        raw_env_value = os.getenv("AGENT_RECURSION_LIMIT")
+        logger.warning(
+            f"Invalid AGENT_RECURSION_LIMIT value: '{raw_env_value}'. "
+            f"Using default value {default_recursion_limit}."
+        )
+        recursion_limit = default_recursion_limit
+
+    result = await agent.ainvoke(
+        input=agent_input, config={"recursion_limit": recursion_limit}
+    )
 
     # Process the result
     response_content = result["messages"][-1].content