fix:env AGENT_RECURSION_LIMIT not work (#453)

* fix:env AGENT_RECURSION_LIMIT not work

* fix:add test

* black tests/unit/config/test_configuration.py

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

src/config/configuration.py

@@ -1,6 +1,7 @@
 # Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
+import logging
 import os
 from dataclasses import dataclass, field, fields
 from typing import Any, Optional
@@ -10,6 +11,39 @@ from langchain_core.runnables import RunnableConfig
 from src.rag.retriever import Resource
 from src.config.report_style import ReportStyle
 
+logger = logging.getLogger(__name__)
+
+
+def get_recursion_limit(default: int = 25) -> int:
+    """Get the recursion limit from environment variable or use default.
+
+    Args:
+        default: Default recursion limit if environment variable is not set or invalid
+
+    Returns:
+        int: The recursion limit to use
+    """
+    try:
+        env_value_str = os.getenv("AGENT_RECURSION_LIMIT", str(default))
+        parsed_limit = int(env_value_str)
+
+        if parsed_limit > 0:
+            logger.info(f"Recursion limit set to: {parsed_limit}")
+            return parsed_limit
+        else:
+            logger.warning(
+                f"AGENT_RECURSION_LIMIT value '{env_value_str}' (parsed as {parsed_limit}) is not positive. "
+                f"Using default value {default}."
+            )
+            return default
+    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}."
+        )
+        return default
+
 
 @dataclass(kw_only=True)
 class Configuration:

src/server/app.py

@@ -14,6 +14,7 @@ from fastapi.responses import Response, StreamingResponse
 from langchain_core.messages import AIMessageChunk, BaseMessage, ToolMessage
 from langgraph.types import Command
 
+from src.config.configuration import get_recursion_limit
 from src.config.report_style import ReportStyle
 from src.config.tools import SELECTED_RAG_PROVIDER
 from src.graph.builder import build_graph_with_memory
@@ -150,6 +151,7 @@ async def _astream_workflow_generator(
             "mcp_settings": mcp_settings,
             "report_style": report_style.value,
             "enable_deep_thinking": enable_deep_thinking,
+            "recursion_limit": get_recursion_limit(),
         },
         stream_mode=["messages", "updates"],
         subgraphs=True,

src/workflow.py

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 import logging
+from src.config.configuration import get_recursion_limit
 from src.graph import build_graph
 
 # Configure logging
@@ -71,7 +72,7 @@ async def run_agent_workflow_async(
                 }
             },
         },
-        "recursion_limit": 100,
+        "recursion_limit": get_recursion_limit(default=100),
     }
     last_message_cnt = 0
     async for s in graph.astream(

tests/unit/config/test_configuration.py

@@ -88,3 +88,49 @@ def test_from_runnable_config_with_no_config():
     assert config.max_search_results == 3
     assert config.resources == []
     assert config.mcp_settings is None
+
+
+def test_get_recursion_limit_default():
+    from src.config.configuration import get_recursion_limit
+
+    result = get_recursion_limit()
+    assert result == 25
+
+
+def test_get_recursion_limit_custom_default():
+    from src.config.configuration import get_recursion_limit
+
+    result = get_recursion_limit(50)
+    assert result == 50
+
+
+def test_get_recursion_limit_from_env(monkeypatch):
+    from src.config.configuration import get_recursion_limit
+
+    monkeypatch.setenv("AGENT_RECURSION_LIMIT", "100")
+    result = get_recursion_limit()
+    assert result == 100
+
+
+def test_get_recursion_limit_invalid_env_value(monkeypatch):
+    from src.config.configuration import get_recursion_limit
+
+    monkeypatch.setenv("AGENT_RECURSION_LIMIT", "invalid")
+    result = get_recursion_limit()
+    assert result == 25
+
+
+def test_get_recursion_limit_negative_env_value(monkeypatch):
+    from src.config.configuration import get_recursion_limit
+
+    monkeypatch.setenv("AGENT_RECURSION_LIMIT", "-5")
+    result = get_recursion_limit()
+    assert result == 25
+
+
+def test_get_recursion_limit_zero_env_value(monkeypatch):
+    from src.config.configuration import get_recursion_limit
+
+    monkeypatch.setenv("AGENT_RECURSION_LIMIT", "0")
+    result = get_recursion_limit()
+    assert result == 25