Add Shell Tool (#3335)

Create an official bash shell tool to replace the dynamically generated one

docs/modules/agents/tools/examples/bash.ipynb

@@ -5,158 +5,158 @@
       "id": "8f210ec3",
       "metadata": {},
       "source": [
-        "# Bash\n",
-        "It can often be useful to have an LLM generate bash commands, and then run them. A common use case for this is letting the LLM interact with your local file system. We provide an easy util to execute bash commands."
+        "# Shell Tool\n",
+        "\n",
+        "Giving agents access to the shell is powerful (though risky outside a sandboxed environment).\n",
+        "\n",
+        "The LLM can use it to execute any shell commands. A common use case for this is letting the LLM interact with your local file system."
       ]
     },
     {
       "cell_type": "code",
       "execution_count": 1,
       "id": "f7b3767b",
-      "metadata": {},
+      "metadata": {
+        "tags": []
+      },
       "outputs": [],
       "source": [
-        "from langchain.utilities import BashProcess"
+        "from langchain.tools import ShellTool\n",
+        "\n",
+        "shell_tool = ShellTool()"
       ]
     },
     {
       "cell_type": "code",
       "execution_count": 2,
-      "id": "cf1c92f0",
-      "metadata": {},
-      "outputs": [],
-      "source": [
-        "bash = BashProcess()"
-      ]
-    },
-    {
-      "cell_type": "code",
-      "execution_count": 3,
-      "id": "2fa952fc",
-      "metadata": {},
+      "id": "c92ac832-556b-4f66-baa4-b78f965dfba0",
+      "metadata": {
+        "tags": []
+      },
       "outputs": [
         {
           "name": "stdout",
           "output_type": "stream",
           "text": [
-            "apify.ipynb\n",
-            "arxiv.ipynb\n",
-            "bash.ipynb\n",
-            "bing_search.ipynb\n",
-            "chatgpt_plugins.ipynb\n",
-            "ddg.ipynb\n",
-            "google_places.ipynb\n",
-            "google_search.ipynb\n",
-            "google_serper.ipynb\n",
-            "gradio_tools.ipynb\n",
-            "human_tools.ipynb\n",
-            "ifttt.ipynb\n",
-            "openweathermap.ipynb\n",
-            "python.ipynb\n",
-            "requests.ipynb\n",
-            "search_tools.ipynb\n",
-            "searx_search.ipynb\n",
-            "serpapi.ipynb\n",
-            "wikipedia.ipynb\n",
-            "wolfram_alpha.ipynb\n",
-            "zapier.ipynb\n",
+            "Hello World!\n",
+            "\n",
+            "real\t0m0.000s\n",
+            "user\t0m0.000s\n",
+            "sys\t0m0.000s\n",
             "\n"
           ]
-        }
-      ],
-      "source": [
-        "print(bash.run(\"ls\"))"
-      ]
-    },
-    {
-      "cell_type": "code",
-      "execution_count": 4,
-      "id": "e7896f8e",
-      "metadata": {},
-      "outputs": [
+        },
         {
-          "name": "stdout",
+          "name": "stderr",
           "output_type": "stream",
           "text": [
-            "apify.ipynb\n",
-            "arxiv.ipynb\n",
-            "bash.ipynb\n",
-            "bing_search.ipynb\n",
-            "chatgpt_plugins.ipynb\n",
-            "ddg.ipynb\n",
-            "google_places.ipynb\n",
-            "google_search.ipynb\n",
-            "google_serper.ipynb\n",
-            "gradio_tools.ipynb\n",
-            "human_tools.ipynb\n",
-            "ifttt.ipynb\n",
-            "openweathermap.ipynb\n",
-            "python.ipynb\n",
-            "requests.ipynb\n",
-            "search_tools.ipynb\n",
-            "searx_search.ipynb\n",
-            "serpapi.ipynb\n",
-            "wikipedia.ipynb\n",
-            "wolfram_alpha.ipynb\n",
-            "zapier.ipynb\n",
-            "\n"
+            "/Users/wfh/code/lc/lckg/langchain/tools/shell/tool.py:34: UserWarning: The shell tool has no safeguards by default. Use at your own risk.\n",
+            "  warnings.warn(\n"
           ]
         }
       ],
       "source": [
-        "bash.run(\"cd ..\")\n",
-        "# The commands are executed in a new subprocess each time, meaning that\n",
-        "# this call will return the same results as the last.\n",
-        "print(bash.run(\"ls\"))"
+        "print(shell_tool.run({\"commands\": [\"echo 'Hello World!'\", \"time\"]}))"
       ]
     },
     {
-      "attachments": {},
       "cell_type": "markdown",
-      "id": "851fee9f",
+      "id": "2fa952fc",
       "metadata": {},
       "source": [
-        "## Terminal Persistance\n",
+        "### Use with Agents\n",
         "\n",
-        "By default, the bash command will be executed in a new subprocess each time. To retain a persistent bash session, we can use the `persistent=True` arg."
+        "As with all tools, these can be given to an agent to accomplish more complex tasks. Let's have the agent fetch some links from a web page."
       ]
     },
     {
       "cell_type": "code",
-      "execution_count": 5,
-      "id": "4a93ea2c",
-      "metadata": {},
-      "outputs": [],
-      "source": [
-        "bash = BashProcess(persistent=True)"
-      ]
-    },
-    {
-      "cell_type": "code",
-      "execution_count": 6,
-      "id": "a1e98b78",
-      "metadata": {},
+      "execution_count": 3,
+      "id": "851fee9f",
+      "metadata": {
+        "tags": []
+      },
       "outputs": [
         {
           "name": "stdout",
           "output_type": "stream",
           "text": [
-            "custom_tools.ipynb\t\tmulti_input_tool.ipynb\n",
-            "examples\t\t\ttool_input_validation.ipynb\n",
-            "getting_started.md\n"
+            "\n",
+            "\n",
+            "\u001b[1m> Entering new AgentExecutor chain...\u001b[0m\n",
+            "\u001b[32;1m\u001b[1;3mQuestion: What is the task?\n",
+            "Thought: We need to download the langchain.com webpage and extract all the URLs from it. Then we need to sort the URLs and return them.\n",
+            "Action:\n",
+            "```\n",
+            "{\n",
+            "  \"action\": \"shell\",\n",
+            "  \"action_input\": {\n",
+            "    \"commands\": [\n",
+            "      \"curl -s https://langchain.com | grep -o 'http[s]*://[^\\\" ]*' | sort\"\n",
+            "    ]\n",
+            "  }\n",
+            "}\n",
+            "```\n",
+            "\u001b[0m"
           ]
+        },
+        {
+          "name": "stderr",
+          "output_type": "stream",
+          "text": [
+            "/Users/wfh/code/lc/lckg/langchain/tools/shell/tool.py:34: UserWarning: The shell tool has no safeguards by default. Use at your own risk.\n",
+            "  warnings.warn(\n"
+          ]
+        },
+        {
+          "name": "stdout",
+          "output_type": "stream",
+          "text": [
+            "\n",
+            "Observation: \u001b[36;1m\u001b[1;3mhttps://blog.langchain.dev/\n",
+            "https://discord.gg/6adMQxSpJS\n",
+            "https://docs.langchain.com/docs/\n",
+            "https://github.com/hwchase17/chat-langchain\n",
+            "https://github.com/hwchase17/langchain\n",
+            "https://github.com/hwchase17/langchainjs\n",
+            "https://github.com/sullivan-sean/chat-langchainjs\n",
+            "https://js.langchain.com/docs/\n",
+            "https://python.langchain.com/en/latest/\n",
+            "https://twitter.com/langchainai\n",
+            "\u001b[0m\n",
+            "Thought:\u001b[32;1m\u001b[1;3mThe URLs have been successfully extracted and sorted. We can return the list of URLs as the final answer.\n",
+            "Final Answer: [\"https://blog.langchain.dev/\", \"https://discord.gg/6adMQxSpJS\", \"https://docs.langchain.com/docs/\", \"https://github.com/hwchase17/chat-langchain\", \"https://github.com/hwchase17/langchain\", \"https://github.com/hwchase17/langchainjs\", \"https://github.com/sullivan-sean/chat-langchainjs\", \"https://js.langchain.com/docs/\", \"https://python.langchain.com/en/latest/\", \"https://twitter.com/langchainai\"]\u001b[0m\n",
+            "\n",
+            "\u001b[1m> Finished chain.\u001b[0m\n"
+          ]
+        },
+        {
+          "data": {
+            "text/plain": [
+              "'[\"https://blog.langchain.dev/\", \"https://discord.gg/6adMQxSpJS\", \"https://docs.langchain.com/docs/\", \"https://github.com/hwchase17/chat-langchain\", \"https://github.com/hwchase17/langchain\", \"https://github.com/hwchase17/langchainjs\", \"https://github.com/sullivan-sean/chat-langchainjs\", \"https://js.langchain.com/docs/\", \"https://python.langchain.com/en/latest/\", \"https://twitter.com/langchainai\"]'"
+            ]
+          },
+          "execution_count": 3,
+          "metadata": {},
+          "output_type": "execute_result"
         }
       ],
       "source": [
-        "bash.run(\"cd ..\")\n",
-        "# Note the list of files is different\n",
-        "print(bash.run(\"ls\"))"
+        "from langchain.chat_models import ChatOpenAI\n",
+        "from langchain.agents import initialize_agent\n",
+        "from langchain.agents import AgentType\n",
+        "\n",
+        "llm = ChatOpenAI(temperature=0)\n",
+        "\n",
+        "shell_tool.description = shell_tool.description + f\"args {shell_tool.args}\".replace(\"{\", \"{{\").replace(\"}\", \"}}\")\n",
+        "self_ask_with_search = initialize_agent([shell_tool], llm, agent=AgentType.CHAT_ZERO_SHOT_REACT_DESCRIPTION, verbose=True)\n",
+        "self_ask_with_search.run(\"Download the langchain.com webpage and grep for all urls. Return only a sorted list of them. Be sure to use double quotes.\")"
       ]
     },
     {
       "cell_type": "code",
       "execution_count": null,
-      "id": "e13c1c9c",
+      "id": "8d0ea3ac-0890-4e39-9cec-74bd80b4b8b8",
       "metadata": {},
       "outputs": [],
       "source": []

langchain/agents/load_tools.py

@@ -27,6 +27,7 @@ from langchain.tools.requests.tool import (
     RequestsPutTool,
 )
 from langchain.tools.searx_search.tool import SearxSearchResults, SearxSearchRun
+from langchain.tools.shell.tool import ShellTool
 from langchain.tools.wikipedia.tool import WikipediaQueryRun
 from langchain.tools.wolfram_alpha.tool import WolframAlphaQueryRun
 from langchain.utilities import ArxivAPIWrapper
@@ -67,11 +68,7 @@ def _get_tools_requests_delete() -> BaseTool:
 
 
 def _get_terminal() -> BaseTool:
-    return Tool(
-        name="Terminal",
-        description="Executes commands in a terminal. Input should be valid commands, and the output will be any output from running that command.",
-        func=BashProcess().run,
-    )
+    return ShellTool()
 
 
 _BASE_TOOLS: Dict[str, Callable[[], BaseTool]] = {

langchain/tools/__init__.py

@@ -26,9 +26,11 @@ from langchain.tools.playwright import (
     NavigateTool,
 )
 from langchain.tools.plugin import AIPluginTool
+from langchain.tools.shell.tool import ShellTool
 
 __all__ = [
     "AIPluginTool",
+    "APIOperation",
     "BaseBrowserTool",
     "BaseTool",
     "BaseTool",
@@ -55,6 +57,6 @@ __all__ = [
     "NavigateTool",
     "OpenAPISpec",
     "ReadFileTool",
+    "ShellTool",
     "WriteFileTool",
-    "APIOperation",
 ]

langchain/tools/shell/__init__.py

@@ -0,0 +1,5 @@
+"""Shell tool."""
+
+from langchain.tools.shell.tool import ShellTool
+
+__all__ = ["ShellTool"]

langchain/tools/shell/tool.py

@@ -0,0 +1,71 @@
+import asyncio
+import platform
+import warnings
+from typing import List, Type
+
+from pydantic import BaseModel, Field, root_validator
+
+from langchain.tools.base import BaseTool
+from langchain.utilities.bash import BashProcess
+
+
+class ShellInput(BaseModel):
+    """Commands for the Bash Shell tool."""
+
+    commands: List[str] = Field(
+        ...,
+        description="List of shell commands to run. Deserialized using json.loads",
+    )
+    """List of shell commands to run."""
+
+    @root_validator
+    def _validate_commands(cls, values: dict) -> dict:
+        """Validate commands."""
+        # TODO: Add real validators
+        commands = values.get("commands")
+        if not isinstance(commands, list):
+            values["commands"] = [commands]
+        # Warn that the bash tool is not safe
+        warnings.warn(
+            "The shell tool has no safeguards by default. Use at your own risk."
+        )
+        return values
+
+
+def _get_default_bash_processs() -> BashProcess:
+    """Get file path from string."""
+    return BashProcess(return_err_output=True)
+
+
+def _get_platform() -> str:
+    """Get platform."""
+    system = platform.system()
+    if system == "Darwin":
+        return "MacOS"
+    return system
+
+
+class ShellTool(BaseTool):
+    """Tool to run shell commands."""
+
+    process: BashProcess = Field(default_factory=_get_default_bash_processs)
+    """Bash process to run commands."""
+
+    name: str = "terminal"
+    """Name of tool."""
+
+    description: str = f"Run shell commands on this {_get_platform()} machine."
+    """Description of tool."""
+
+    args_schema: Type[BaseModel] = ShellInput
+    """Schema for input arguments."""
+
+    def _run(self, commands: List[str]) -> str:
+        """Run commands and return final output."""
+        return self.process.run(commands)
+
+    async def _arun(self, commands: List[str]) -> str:
+        """Run commands asynchronously and return final output."""
+        return await asyncio.get_event_loop().run_in_executor(
+            None, self.process.run, commands
+        )

tests/unit_tests/tools/shell/test_shell.py

@@ -0,0 +1,43 @@
+import warnings
+
+import pytest
+
+from langchain.tools.shell.tool import ShellInput, ShellTool
+
+# Test data
+test_commands = ["echo 'Hello, World!'", "echo 'Another command'"]
+
+
+def test_shell_input_validation() -> None:
+    shell_input = ShellInput(commands=test_commands)
+    assert isinstance(shell_input.commands, list)
+    assert len(shell_input.commands) == 2
+
+    with warnings.catch_warnings(record=True) as w:
+        ShellInput(commands=test_commands)
+        assert len(w) == 1
+        assert (
+            str(w[-1].message)
+            == "The shell tool has no safeguards by default. Use at your own risk."
+        )
+
+
+def test_shell_tool_init() -> None:
+    shell_tool = ShellTool()
+    assert shell_tool.name == "terminal"
+    assert isinstance(shell_tool.description, str)
+    assert shell_tool.args_schema == ShellInput
+    assert shell_tool.process is not None
+
+
+@pytest.mark.asyncio
+async def test_shell_tool_arun() -> None:
+    shell_tool = ShellTool()
+    result = await shell_tool._arun(commands=test_commands)
+    assert result.strip() == "Hello, World!\nAnother command"
+
+
+def test_shell_tool_run() -> None:
+    shell_tool = ShellTool()
+    result = shell_tool._run(commands=test_commands)
+    assert result.strip() == "Hello, World!\nAnother command"