diff --git a/backend/package/yuxi/agents/backends/sandbox/paths.py b/backend/package/yuxi/agents/backends/sandbox/paths.py
index 04976085..e949414f 100644
--- a/backend/package/yuxi/agents/backends/sandbox/paths.py
+++ b/backend/package/yuxi/agents/backends/sandbox/paths.py
@@ -4,21 +4,19 @@ import re
 from pathlib import Path
 
 from yuxi import config as conf
+from yuxi.utils.paths import (
+    VIRTUAL_PATH_PREFIX,
+    WORKSPACE_DIR_NAME,
+    OUTPUTS_DIR_NAME,
+    UPLOADS_DIR_NAME
+)
 
-DEFAULT_VIRTUAL_PATH_PREFIX = "/home/gem/user-data"
-VIRTUAL_PATH_PREFIX = DEFAULT_VIRTUAL_PATH_PREFIX
-_WORKSPACE_DIR_NAME = "workspace"
-_UPLOADS_DIR_NAME = "uploads"
-_OUTPUTS_DIR_NAME = "outputs"
 
 _SAFE_THREAD_ID_RE = re.compile(r"^[A-Za-z0-9_-]+$")
 
 
 def get_virtual_path_prefix() -> str:
-    configured = str(getattr(conf, "sandbox_virtual_path_prefix", "") or "").strip()
-    if not configured:
-        return DEFAULT_VIRTUAL_PATH_PREFIX
-    return "/" + configured.strip("/")
+    return "/" + VIRTUAL_PATH_PREFIX.strip("/")
 
 
 def _validate_thread_id(thread_id: str) -> str:
@@ -46,15 +44,15 @@ def sandbox_user_data_dir(thread_id: str) -> Path:
 
 def sandbox_workspace_dir(thread_id: str) -> Path:
     _validate_thread_id(thread_id)
-    return _global_user_data_dir() / _WORKSPACE_DIR_NAME
+    return _global_user_data_dir() / WORKSPACE_DIR_NAME
 
 
 def sandbox_uploads_dir(thread_id: str) -> Path:
-    return _thread_root_dir(thread_id) / _UPLOADS_DIR_NAME
+    return _thread_root_dir(thread_id) / UPLOADS_DIR_NAME
 
 
 def sandbox_outputs_dir(thread_id: str) -> Path:
-    return _thread_root_dir(thread_id) / _OUTPUTS_DIR_NAME
+    return _thread_root_dir(thread_id) / OUTPUTS_DIR_NAME
 
 
 def ensure_thread_dirs(thread_id: str) -> None:
@@ -72,16 +70,16 @@ def _resolve_user_data_base_dir(thread_id: str, relative_path: str) -> tuple[Pat
         return base_dir.resolve(), base_dir.resolve()
 
     namespace = parts[0]
-    if namespace == _WORKSPACE_DIR_NAME:
+    if namespace == WORKSPACE_DIR_NAME:
         # Workspace is shared across threads, so it lives outside the per-thread root.
         base_dir = sandbox_workspace_dir(thread_id)
         target_path = base_dir.joinpath(*parts[1:]) if len(parts) > 1 else base_dir
         return base_dir.resolve(), target_path.resolve()
-    if namespace == _UPLOADS_DIR_NAME:
+    if namespace == UPLOADS_DIR_NAME:
         base_dir = sandbox_uploads_dir(thread_id)
         target_path = base_dir.joinpath(*parts[1:]) if len(parts) > 1 else base_dir
         return base_dir.resolve(), target_path.resolve()
-    if namespace == _OUTPUTS_DIR_NAME:
+    if namespace == OUTPUTS_DIR_NAME:
         base_dir = sandbox_outputs_dir(thread_id)
         target_path = base_dir.joinpath(*parts[1:]) if len(parts) > 1 else base_dir
         return base_dir.resolve(), target_path.resolve()
@@ -124,7 +122,7 @@ def virtual_path_for_thread_file(thread_id: str, path: str | Path) -> str:
     else:
         workspace_relative = relative_path.as_posix()
         relative_path_str = (
-            _WORKSPACE_DIR_NAME if workspace_relative in {"", "."} else f"{_WORKSPACE_DIR_NAME}/{workspace_relative}"
+            WORKSPACE_DIR_NAME if workspace_relative in {"", "."} else f"{WORKSPACE_DIR_NAME}/{workspace_relative}"
         )
 
     prefix = get_virtual_path_prefix().rstrip("/")
diff --git a/backend/package/yuxi/agents/buildin/chatbot/prompt.py b/backend/package/yuxi/agents/buildin/chatbot/prompt.py
index 367fd924..591b7bdc 100644
--- a/backend/package/yuxi/agents/buildin/chatbot/prompt.py
+++ b/backend/package/yuxi/agents/buildin/chatbot/prompt.py
@@ -1,19 +1,28 @@
-PROMPT = """
+from yuxi.utils.paths import (
+    VIRTUAL_PATH_PREFIX,
+    VIRTUAL_PATH_WORKSPACE,
+    VIRTUAL_PATH_OUTPUTS,
+    VIRTUAL_PATH_UPLOADS,
+    VIRTUAL_KBS_PATH
+)
+
+
+PROMPT = f"""
 你是一个人工智能助手 “语析”，专门用来回答用户的问题。请根据用户提供的信息，尽可能详细地回答问题。
 如果你不确定答案，可以说你不知道，但请尽量提供相关的信息或建议。请保持礼貌和专业。
 
-系统主要工作路径为 /home/gem/user-data/，但必须遵守规范：
-- /home/gem/user-data/workspace/：用于存放工作文件（用户目录，不要轻易写入）
-- /home/gem/user-data/outputs/：用于写入的文件夹
-    - /home/gem/user-data/outputs/tmp/：用于存放中间结果或备份内容
-- /home/gem/user-data/uploads/：用于存放用户上传的文件
+系统主要工作路径为 {VIRTUAL_PATH_PREFIX}，但必须遵守规范：
+- {VIRTUAL_PATH_WORKSPACE}：用于存放工作文件（用户目录，不要轻易写入）
+- {VIRTUAL_PATH_OUTPUTS}：用于写入的文件夹
+    - {VIRTUAL_PATH_OUTPUTS}/tmp/：用于存放中间结果或备份内容
+- {VIRTUAL_PATH_UPLOADS}：用于存放用户上传的文件
 
 非必要不写入其他路径
 
 如果启用了知识库，除了使用知识库工具之外，
 当需要精准获取信息的时候，或者 query_kb 中没有找到相关的内容，还可以直接访问知识库文件系统
-（路径为 /home/gem/kbs/）来获取信息。
-源文件可能无法解析，可以在 /home/gem/kbs/<db_name>/parsed/ 中找到解析后的 markdown 文件。
+（路径为 {VIRTUAL_KBS_PATH}）来获取信息。
+源文件可能无法解析，可以在 {VIRTUAL_KBS_PATH}/<db_name>/parsed/ 中找到解析后的 markdown 文件。
 
 你需要根据任务的复杂程度来使用 write_todos 来记录规划和待办事项，确保任务的每个步骤都被记录和跟踪。
 """
diff --git a/backend/package/yuxi/agents/buildin/deep_agent/prompt.py b/backend/package/yuxi/agents/buildin/deep_agent/prompt.py
index 02b3da70..983d3690 100644
--- a/backend/package/yuxi/agents/buildin/deep_agent/prompt.py
+++ b/backend/package/yuxi/agents/buildin/deep_agent/prompt.py
@@ -1,4 +1,12 @@
-DEEP_PROMPT = """你是一位专家级研究员。你的工作是进行彻底的研究，然后撰写一份精美的报告。
+from yuxi.utils.paths import (
+    VIRTUAL_PATH_PREFIX,
+    VIRTUAL_PATH_WORKSPACE,
+    VIRTUAL_PATH_OUTPUTS,
+    VIRTUAL_PATH_UPLOADS,
+)
+
+
+DEEP_PROMPT = f"""你是一位专家级研究员。你的工作是进行彻底的研究，然后撰写一份精美的报告。
 
 你应该做的第一件事是把原始的用户问题写入 `question.txt`，以便你有一个记录。
 
@@ -78,9 +86,9 @@ DEEP_PROMPT = """你是一位专家级研究员。你的工作是进行彻底的
 
 你可以使用一些工具。
 
-允许的写入路径为 /home/gem/user-data/，请将需要保存的文件写入该目录下。
-推荐使用的路径：
-- /home/gem/user-data/workspace/：用于存放工作文件和中间结果
-- /home/gem/user-data/outputs/：用于存放最终输出结果
-- /home/gem/user-data/uploads/：用于存放用户上传的文件
+系统主要工作路径为 {VIRTUAL_PATH_PREFIX}，但必须遵守规范：
+- {VIRTUAL_PATH_WORKSPACE}：用于存放工作文件（用户目录，不要轻易写入）
+- {VIRTUAL_PATH_OUTPUTS}：用于写入的文件夹
+    - {VIRTUAL_PATH_OUTPUTS}/tmp/：用于存放中间结果或备份内容
+- {VIRTUAL_PATH_UPLOADS}：用于存放用户上传的文件
 """
diff --git a/backend/package/yuxi/agents/toolkits/buildin/tools.py b/backend/package/yuxi/agents/toolkits/buildin/tools.py
index 7b9a984d..3dfcfd98 100644
--- a/backend/package/yuxi/agents/toolkits/buildin/tools.py
+++ b/backend/package/yuxi/agents/toolkits/buildin/tools.py
@@ -16,6 +16,7 @@ from yuxi.agents.toolkits.registry import ToolExtraMetadata, _all_tool_instances
 from yuxi.storage.minio import aupload_file_to_minio
 from yuxi.utils import logger
 from yuxi.utils.question_utils import normalize_questions
+from yuxi.utils.paths import VIRTUAL_PATH_OUTPUTS
 
 # Lazy initialization for TavilySearch (only when API key is available)
 _tavily_search_instance = None
@@ -67,7 +68,7 @@ class PresentArtifactsInput(BaseModel):
     """Expose artifact files to the frontend after the agent finishes."""
 
     filepaths: list[str] = Field(
-        description="需要展示给用户的文件绝对路径列表，只允许位于 /home/gem/user-data/outputs/ 下"
+        description=f"需要展示给用户的文件绝对路径列表，只允许位于 {VIRTUAL_PATH_OUTPUTS} 下"
     )
 
 
@@ -130,16 +131,16 @@ def calculator(a: float, b: float, operation: str) -> float:
         raise
 
 
-PRESENT_ARTIFACTS_DESCRIPTION = """
+PRESENT_ARTIFACTS_DESCRIPTION = f"""
 将已经生成好的结果文件展示给用户。
 
 使用场景：
-1. 你已经在 `/home/gem/user-data/outputs/` 下写好了最终结果文件
+1. 你已经在 `{VIRTUAL_PATH_OUTPUTS}` 下写好了最终结果文件
 2. 你希望前端在对话结束后显示这些结果文件卡片
 3. 这些文件需要支持下载或预览
 
 注意事项：
-1. 只能传入 `/home/gem/user-data/outputs/` 下的文件
+1. 只能传入 `{VIRTUAL_PATH_OUTPUTS}` 下的文件
 2. 不要传入中间过程文件，只有真正需要给用户看的结果文件才调用
 3. 可以一次传多个文件
 """
diff --git a/backend/package/yuxi/services/conversation_service.py b/backend/package/yuxi/services/conversation_service.py
index 6ab17977..46cde9f0 100644
--- a/backend/package/yuxi/services/conversation_service.py
+++ b/backend/package/yuxi/services/conversation_service.py
@@ -13,12 +13,14 @@ from yuxi.agents.buildin import agent_manager
 from yuxi.config import config as app_config
 from yuxi.plugins.parser import Parser
 from yuxi.repositories.conversation_repository import ConversationRepository
-from yuxi.services.doc_converter import ATTACHMENT_ALLOWED_EXTENSIONS, MAX_ATTACHMENT_SIZE_BYTES
 from yuxi.utils.datetime_utils import utc_isoformat
 from yuxi.utils.logging_config import logger
+from yuxi.utils.paths import VIRTUAL_PATH_UPLOADS
 
-UPLOADS_VIRTUAL_PREFIX = "/home/gem/user-data/uploads"
+ATTACHMENT_ALLOWED_EXTENSIONS: tuple[str, ...] = ()
+MAX_ATTACHMENT_SIZE_BYTES = 5 * 1024 * 1024  # 5 MB
 MAX_ATTACHMENT_MARKDOWN_CHARS = 32_000
+MAX_ATTACHMENT_MARKDOWN_CHARS = 32_000  # TODO: 转 MARKDOWN的时候，不应该裁剪
 
 
 @dataclass(slots=True)
@@ -107,7 +109,7 @@ async def require_user_conversation(conv_repo: ConversationRepository, thread_id
 
 def _make_upload_virtual_path(file_name: str) -> str:
     safe_name = file_name.replace("/", "_").replace("\\", "_").strip(" .")
-    return f"{UPLOADS_VIRTUAL_PREFIX}/{safe_name or 'attachment.bin'}"
+    return f"{VIRTUAL_PATH_UPLOADS}/{safe_name or 'attachment.bin'}"
 
 
 def _make_attachment_path(file_name: str) -> str:
@@ -127,7 +129,7 @@ def _make_attachment_path(file_name: str) -> str:
 def _build_attachment_storage_path(*, user_id: str, thread_id: str, file_name: str) -> tuple[str, Path]:
     """返回附件虚拟路径和宿主机落盘路径。"""
     relative_name = _make_attachment_path(file_name)
-    virtual_path = f"/home/gem/user-data/uploads/attachments/{relative_name}"
+    virtual_path = f"{VIRTUAL_PATH_UPLOADS}/attachments/{relative_name}"
 
     host_dir = Path(app_config.save_dir) / "threads" / thread_id / "user-data" / "uploads" / "attachments"
     host_dir.mkdir(parents=True, exist_ok=True)
diff --git a/backend/package/yuxi/services/doc_converter.py b/backend/package/yuxi/services/doc_converter.py
deleted file mode 100644
index a32427e9..00000000
--- a/backend/package/yuxi/services/doc_converter.py
+++ /dev/null
@@ -1,94 +0,0 @@
-"""Helpers for converting uploaded documents into markdown snippets."""
-
-from __future__ import annotations
-
-import uuid
-from dataclasses import dataclass
-from pathlib import Path
-
-import aiofiles
-from fastapi import UploadFile
-from yuxi.config import config as app_config
-from yuxi.plugins.parser import Parser
-from yuxi.utils import logger
-
-ATTACHMENT_ALLOWED_EXTENSIONS: tuple[str, ...] = ()
-MAX_ATTACHMENT_SIZE_BYTES = 5 * 1024 * 1024  # 5 MB
-MAX_ATTACHMENT_MARKDOWN_CHARS = 32_000
-
-
-@dataclass(slots=True)
-class ConversionResult:
-    """Represents the normalized output of an uploaded attachment."""
-
-    file_id: str
-    file_name: str
-    file_type: str | None
-    file_size: int
-    markdown: str
-    truncated: bool
-
-
-def _ensure_workdir() -> Path:
-    workdir = Path(app_config.save_dir) / "uploads" / "chat_attachments"
-    workdir.mkdir(parents=True, exist_ok=True)
-    return workdir
-
-
-async def _write_upload_to_disk(upload: UploadFile, dest: Path) -> int:
-    await upload.seek(0)
-    written = 0
-    chunk_size = 1024 * 1024
-
-    async with aiofiles.open(dest, "wb") as buffer:
-        while True:
-            chunk = await upload.read(chunk_size)
-            if not chunk:
-                break
-            written += len(chunk)
-            if written > MAX_ATTACHMENT_SIZE_BYTES:
-                raise ValueError("附件过大，当前仅支持 5 MB 以内的文件")
-            await buffer.write(chunk)
-
-    return written
-
-
-def _truncate_markdown(markdown: str) -> tuple[str, bool]:
-    if len(markdown) <= MAX_ATTACHMENT_MARKDOWN_CHARS:
-        return markdown, False
-
-    truncated_content = markdown[: MAX_ATTACHMENT_MARKDOWN_CHARS - 100].rstrip()
-    truncated_content = f"{truncated_content}\n\n[内容已截断，超出 {MAX_ATTACHMENT_MARKDOWN_CHARS} 字符限制]"
-    return truncated_content, True
-
-
-async def convert_upload_to_markdown(upload: UploadFile) -> ConversionResult:
-    """Persist an UploadFile temporarily, convert it to markdown, and clean up."""
-    if not upload.filename:
-        raise ValueError("无法识别的文件名")
-
-    file_name = Path(upload.filename).name
-    suffix = Path(file_name).suffix.lower()
-
-    if ATTACHMENT_ALLOWED_EXTENSIONS and suffix not in ATTACHMENT_ALLOWED_EXTENSIONS:
-        allowed = ", ".join(ATTACHMENT_ALLOWED_EXTENSIONS)
-        raise ValueError(f"不支持的文件类型: {suffix or '未知'}，当前仅支持 {allowed}")
-
-    temp_dir = _ensure_workdir()
-    temp_path = temp_dir / f"{uuid.uuid4().hex}{suffix}"
-
-    try:
-        file_size = await _write_upload_to_disk(upload, temp_path)
-        markdown = await Parser.aparse(str(temp_path))
-        markdown, truncated = _truncate_markdown(markdown)
-        return ConversionResult(
-            file_id=uuid.uuid4().hex,
-            file_name=file_name,
-            file_type=upload.content_type,
-            file_size=file_size,
-            markdown=markdown,
-            truncated=truncated,
-        )
-    except Exception as exc:  # noqa: BLE001
-        logger.error("Attachment conversion failed: %s", exc)
-        raise
diff --git a/backend/package/yuxi/utils/paths.py b/backend/package/yuxi/utils/paths.py
new file mode 100644
index 00000000..79555e1c
--- /dev/null
+++ b/backend/package/yuxi/utils/paths.py
@@ -0,0 +1,25 @@
+from pathlib import Path
+from yuxi import config
+
+VIRTUAL_PATH_PREFIX = config.sandbox_virtual_path_prefix
+WORKSPACE_DIR_NAME = "workspace"
+UPLOADS_DIR_NAME = "uploads"
+OUTPUTS_DIR_NAME = "outputs"
+VIRTUAL_SKILLS_PATH = "/home/gem/skills"
+VIRTUAL_KBS_PATH = "/home/gem/kbs"
+
+VIRTUAL_PATH_WORKSPACE = (Path(VIRTUAL_PATH_PREFIX) / WORKSPACE_DIR_NAME).as_posix()
+VIRTUAL_PATH_UPLOADS = (Path(VIRTUAL_PATH_PREFIX) / UPLOADS_DIR_NAME).as_posix()
+VIRTUAL_PATH_OUTPUTS = (Path(VIRTUAL_PATH_PREFIX) / OUTPUTS_DIR_NAME).as_posix()
+
+__all__ = [
+    "VIRTUAL_PATH_PREFIX",
+    "WORKSPACE_DIR_NAME",
+    "UPLOADS_DIR_NAME",
+    "OUTPUTS_DIR_NAME",
+    "VIRTUAL_PATH_WORKSPACE",
+    "VIRTUAL_PATH_UPLOADS",
+    "VIRTUAL_PATH_OUTPUTS",
+    "VIRTUAL_SKILLS_PATH",
+    "VIRTUAL_KBS_PATH",
+]
diff --git a/backend/server/routers/chat_router.py b/backend/server/routers/chat_router.py
index 6ed2a0c9..8951eb35 100644
--- a/backend/server/routers/chat_router.py
+++ b/backend/server/routers/chat_router.py
@@ -43,6 +43,7 @@ from yuxi.services.feedback_service import get_message_feedback_view, submit_mes
 from yuxi.repositories.agent_config_repository import AgentConfigRepository
 from yuxi.utils.logging_config import logger
 from yuxi.utils.image_processor import process_uploaded_image
+from yuxi.utils.paths import VIRTUAL_PATH_PREFIX
 
 
 # TODO：当前文件的功能过于庞杂，路由标签混乱
@@ -817,7 +818,7 @@ async def delete_thread_attachment(
 @chat.get("/thread/{thread_id}/files", response_model=ThreadFileListResponse)
 async def list_thread_files(
     thread_id: str,
-    path: str = Query("/home/gem/user-data"),
+    path: str = Query(f"{VIRTUAL_PATH_PREFIX}"),
     recursive: bool = Query(False),
     db: AsyncSession = Depends(get_db),
     current_user: User = Depends(get_required_user),