diff --git a/surfsense_backend/app/agents/multi_agent_v1/subagents/utils.py b/surfsense_backend/app/agents/multi_agent_v1/subagents/utils.py
new file mode 100644
index 000000000..fade0a60a
--- /dev/null
+++ b/surfsense_backend/app/agents/multi_agent_v1/subagents/utils.py
@@ -0,0 +1,143 @@
+"""Shared helpers for multi-agent v1 subagents."""
+
+from __future__ import annotations
+
+from collections.abc import Sequence
+from typing import Any
+
+from langchain_core.messages import AIMessage, BaseMessage, HumanMessage
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.agents.new_chat.llm_config import (
+    create_chat_litellm_from_agent_config,
+    load_agent_config,
+)
+
+
+async def load_llm_for_request(
+    *,
+    session: AsyncSession,
+    llm_config_id: int,
+    search_space_id: int,
+) -> Any | None:
+    """Load the configured chat model for a subagent run."""
+    agent_config = await load_agent_config(
+        session=session,
+        config_id=llm_config_id,
+        search_space_id=search_space_id,
+    )
+    if agent_config is None:
+        return None
+    return create_chat_litellm_from_agent_config(agent_config)
+
+
+def build_subagent_input_state(
+    *,
+    goal: str,
+    stream_kwargs: dict[str, Any],
+) -> dict[str, Any]:
+    """Build the initial state payload passed to a subagent."""
+    return {
+        "messages": [HumanMessage(content=goal)],
+        "search_space_id": stream_kwargs["search_space_id"],
+        "request_id": read_optional_nonempty_string(
+            stream_kwargs, "request_id", "unknown"
+        ),
+        "turn_id": f"subagent:{read_optional_integer(stream_kwargs, 'chat_id') or 'unknown'}",
+        "architecture_mode": "multi_agent_v1_subagent",
+    }
+
+
+def build_subagent_run_config(
+    *,
+    stream_kwargs: dict[str, Any],
+    scope: str,
+) -> dict[str, Any]:
+    """Build runnable config with a scope-specific thread id."""
+    return {
+        "configurable": {
+            "thread_id": build_subagent_thread_id(stream_kwargs=stream_kwargs, scope=scope),
+            "request_id": read_optional_nonempty_string(
+                stream_kwargs, "request_id", "unknown"
+            ),
+            "turn_id": f"subagent:{read_optional_integer(stream_kwargs, 'chat_id') or 'unknown'}",
+            "architecture_mode": "multi_agent_v1_subagent",
+        },
+        "recursion_limit": 40,
+    }
+
+
+def build_subagent_error_result(error_class: str) -> dict[str, Any]:
+    """Build a standardized error result payload for subagents."""
+    return {
+        "status": "error",
+        "summary": "",
+        "evidence": [],
+        "artifacts": [],
+        "needs_human": False,
+        "error_class": error_class,
+    }
+
+
+def extract_final_ai_message_text_from_state(state: Any) -> str:
+    """Return the latest AI message text from an agent state payload."""
+    if not isinstance(state, dict):
+        return ""
+    messages = state.get("messages")
+    if not isinstance(messages, Sequence):
+        return ""
+    for message in reversed(messages):
+        if isinstance(message, AIMessage):
+            return extract_plain_text_from_message_content(message).strip()
+    return ""
+
+
+def extract_plain_text_from_message_content(message: BaseMessage) -> str:
+    """Flatten a LangChain message content payload into plain text."""
+    content = getattr(message, "content", "")
+    if isinstance(content, str):
+        return content
+    if isinstance(content, list):
+        parts: list[str] = []
+        for item in content:
+            if isinstance(item, str):
+                parts.append(item)
+            elif isinstance(item, dict) and item.get("type") == "text":
+                parts.append(str(item.get("text", "")))
+        return "\n".join(part for part in parts if part)
+    return str(content)
+
+
+def build_disabled_tools_list(disabled_tools: Any) -> list[str]:
+    """Normalize disabled tools input to a list of tool names."""
+    if not isinstance(disabled_tools, list):
+        return []
+    return [tool_name for tool_name in disabled_tools if isinstance(tool_name, str)]
+
+
+def read_optional_nonempty_string(
+    payload: dict[str, Any],
+    key: str,
+    default: str | None = None,
+) -> str | None:
+    """Read a non-empty string from payload, otherwise return default."""
+    value = payload.get(key)
+    if isinstance(value, str) and value.strip():
+        return value.strip()
+    return default
+
+
+def read_optional_integer(payload: dict[str, Any], key: str) -> int | None:
+    """Read an integer from payload when present and valid."""
+    value = payload.get(key)
+    if isinstance(value, int):
+        return value
+    return None
+
+
+def build_subagent_thread_id(*, stream_kwargs: dict[str, Any], scope: str) -> str:
+    """Build a stable thread id for a scope-specific subagent run."""
+    chat_id = read_optional_integer(stream_kwargs, "chat_id")
+    if chat_id is None:
+        return "ma-subagent:unknown"
+    return f"ma-subagent:{chat_id}:{scope}"