fix: surface configured sandbox mounts to agents (#1638)

* fix: surface configured sandbox mounts to agents

* fix: address PR review feedback

---------

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

backend/packages/harness/deerflow/agents/lead_agent/prompt.py

@@ -477,6 +477,28 @@ def _build_acp_section() -> str:
     )
 
 
+def _build_custom_mounts_section() -> str:
+    """Build a prompt section for explicitly configured sandbox mounts."""
+    try:
+        from deerflow.config import get_app_config
+
+        mounts = get_app_config().sandbox.mounts or []
+    except Exception:
+        logger.exception("Failed to load configured sandbox mounts for the lead-agent prompt")
+        return ""
+
+    if not mounts:
+        return ""
+
+    lines = []
+    for mount in mounts:
+        access = "read-only" if mount.read_only else "read-write"
+        lines.append(f"- Custom mount: `{mount.container_path}` - Host directory mapped into the sandbox ({access})")
+
+    mounts_list = "\n".join(lines)
+    return f"\n**Custom Mounted Directories:**\n{mounts_list}\n- If the user needs files outside `/mnt/user-data`, use these absolute container paths directly when they match the requested directory"
+
+
 def apply_prompt_template(subagent_enabled: bool = False, max_concurrent_subagents: int = 3, *, agent_name: str | None = None, available_skills: set[str] | None = None) -> str:
     # Get memory context
     memory_context = _get_memory_context(agent_name)
@@ -511,6 +533,8 @@ def apply_prompt_template(subagent_enabled: bool = False, max_concurrent_subagen
 
     # Build ACP agent section only if ACP agents are configured
     acp_section = _build_acp_section()
+    custom_mounts_section = _build_custom_mounts_section()
+    acp_and_mounts_section = "\n".join(section for section in (acp_section, custom_mounts_section) if section)
 
     # Format the prompt with dynamic skills and memory
     prompt = SYSTEM_PROMPT_TEMPLATE.format(
@@ -522,7 +546,7 @@ def apply_prompt_template(subagent_enabled: bool = False, max_concurrent_subagen
         subagent_section=subagent_section,
         subagent_reminder=subagent_reminder,
         subagent_thinking=subagent_thinking,
-        acp_section=acp_section,
+        acp_section=acp_and_mounts_section,
     )
 
     return prompt + f"\n<current_date>{datetime.now().strftime('%Y-%m-%d, %A')}</current_date>"

backend/packages/harness/deerflow/runtime/runs/manager.py

@@ -81,7 +81,9 @@ class RunManager:
     async def list_by_thread(self, thread_id: str) -> list[RunRecord]:
         """Return all runs for a given thread, newest first."""
         async with self._lock:
-            return list(reversed([r for r in self._runs.values() if r.thread_id == thread_id]))
+            # Dict insertion order matches creation order, so reversing it gives
+            # us deterministic newest-first results even when timestamps tie.
+            return [r for r in reversed(self._runs.values()) if r.thread_id == thread_id]
 
     async def set_status(self, run_id: str, status: RunStatus, *, error: str | None = None) -> None:
         """Transition a run to a new status."""

backend/packages/harness/deerflow/subagents/builtins/bash_agent.py

@@ -37,6 +37,7 @@ You have access to the sandbox environment:
 - User uploads: `/mnt/user-data/uploads`
 - User workspace: `/mnt/user-data/workspace`
 - Output files: `/mnt/user-data/outputs`
+- Deployment-configured custom mounts may also be available at other absolute container paths; use them directly when the task references those mounted directories
 </working_directory>
 """,
     tools=["bash", "ls", "read_file", "write_file", "str_replace"],  # Sandbox tools only

backend/packages/harness/deerflow/subagents/builtins/general_purpose.py

@@ -38,6 +38,7 @@ You have access to the same sandbox environment as the parent agent:
 - User uploads: `/mnt/user-data/uploads`
 - User workspace: `/mnt/user-data/workspace`
 - Output files: `/mnt/user-data/outputs`
+- Deployment-configured custom mounts may also be available at other absolute container paths; use them directly when the task references those mounted directories
 </working_directory>
 """,
     tools=None,  # Inherit all tools from parent