* fix: add base_dir path containment to FileWriterTool os.path.join does not prevent traversal — joining "./" with "../../../etc/cron.d/pwned" resolves cleanly outside any intended scope. The tool also called os.makedirs on the unvalidated path, meaning it would create arbitrary directory structures. Adds a base_dir parameter that uses os.path.realpath() to resolve the final path (including symlinks) before checking containment. Any filename or directory argument that resolves outside base_dir is rejected before any filesystem operation occurs. When base_dir is not set the tool behaves as before — only use that in fully sandboxed environments. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix: make directory relative to base_dir for better UX When base_dir is set, the directory arg is now treated as a subdirectory of base_dir rather than an absolute path. This means the LLM only needs to specify a filename (and optionally a relative subdirectory) — it does not need to repeat the base_dir path. FileWriterTool(base_dir="./output") → filename="report.txt" writes to ./output/report.txt → filename="f.txt", directory="sub" writes to ./output/sub/f.txt Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix: remove directory field from LLM schema when base_dir is set When a developer sets base_dir, they control where files are written. The LLM should only supply filename and content — not a directory path. Adds ScopedFileWriterToolInput (no directory field) which is used when base_dir is provided at construction, following the same pattern as FileReadTool/ScrapeWebsiteTool. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix: prevent path traversal in FileWriterTool without interface changes Adds containment check inside _run() using os.path.realpath() to ensure the resolved file path stays within the resolved directory. Blocks ../ sequences, absolute filenames, and symlink escapes transparently — no schema or interface changes required. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix: use Path.is_relative_to() for path containment check Replaces startswith(real_directory + os.sep) with Path.is_relative_to(), which does a proper path-component comparison. This avoids the edge case where real_directory == "/" produces a "//" prefix, and is safe on case-insensitive filesystems. Also explicitly rejects the case where the filepath resolves to the directory itself (not a valid file target). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * test: fix portability issues in path traversal tests - test_blocks_traversal_in_filename: use a sibling temp dir instead of asserting against a potentially pre-existing ../outside.txt - test_blocks_absolute_path_in_filename: use a temp-dir-derived absolute path instead of hardcoding /etc/passwd - test_blocks_symlink_escape: symlink to a temp "outside" dir instead of /etc, assert target file was not created Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com> Co-authored-by: Greyson LaLonde <greyson.r.lalonde@gmail.com>
CrewAI Tools
Empower your CrewAI agents with powerful, customizable tools to elevate their capabilities and tackle sophisticated, real-world tasks.
CrewAI Tools provide the essential functionality to extend your agents, helping you rapidly enhance your automations with reliable, ready-to-use tools or custom-built solutions tailored precisely to your needs.
Quick Links
Homepage | Documentation | Examples | Community
Available Tools
CrewAI provides an extensive collection of powerful tools ready to enhance your agents:
- File Management:
FileReadTool,FileWriteTool - Web Scraping:
ScrapeWebsiteTool,SeleniumScrapingTool - Database Integrations:
MySQLSearchTool - Vector Database Integrations:
MongoDBVectorSearchTool,QdrantVectorSearchTool,WeaviateVectorSearchTool - API Integrations:
SerperApiTool,EXASearchTool - AI-powered Tools:
DallETool,VisionTool,StagehandTool
And many more robust tools to simplify your agent integrations.
Creating Custom Tools
CrewAI offers two straightforward approaches to creating custom tools:
Subclassing BaseTool
Define your tool by subclassing:
from crewai.tools import BaseTool
class MyCustomTool(BaseTool):
name: str = "Tool Name"
description: str = "Detailed description here."
def _run(self, *args, **kwargs):
# Your tool logic here
Using the tool Decorator
Quickly create lightweight tools using decorators:
from crewai import tool
@tool("Tool Name")
def my_custom_function(input):
# Tool logic here
return output
CrewAI Tools and MCP
CrewAI Tools supports the Model Context Protocol (MCP). It gives you access to thousands of tools from the hundreds of MCP servers out there built by the community.
Before you start using MCP with CrewAI tools, you need to install the mcp extra dependencies:
pip install crewai-tools[mcp]
# or
uv add crewai-tools --extra mcp
To quickly get started with MCP in CrewAI you have 2 options:
Option 1: Fully managed connection
In this scenario we use a contextmanager (with statement) to start and stop the the connection with the MCP server.
This is done in the background and you only get to interact with the CrewAI tools corresponding to the MCP server's tools.
For an STDIO based MCP server:
from mcp import StdioServerParameters
from crewai_tools import MCPServerAdapter
serverparams = StdioServerParameters(
command="uvx",
args=["--quiet", "pubmedmcp@0.1.3"],
env={"UV_PYTHON": "3.12", **os.environ},
)
with MCPServerAdapter(serverparams) as tools:
# tools is now a list of CrewAI Tools matching 1:1 with the MCP server's tools
agent = Agent(..., tools=tools)
task = Task(...)
crew = Crew(..., agents=[agent], tasks=[task])
crew.kickoff(...)
For an SSE based MCP server:
serverparams = {"url": "http://localhost:8000/sse"}
with MCPServerAdapter(serverparams) as tools:
# tools is now a list of CrewAI Tools matching 1:1 with the MCP server's tools
agent = Agent(..., tools=tools)
task = Task(...)
crew = Crew(..., agents=[agent], tasks=[task])
crew.kickoff(...)
Option 2: More control over the MCP connection
If you need more control over the MCP connection, you can instanciate the MCPServerAdapter into an mcp_server_adapter object which can be used to manage the connection with the MCP server and access the available tools.
important: in this case you need to call mcp_server_adapter.stop() to make sure the connection is correctly stopped. We recommend that you use a try ... finally block run to make sure the .stop() is called even in case of errors.
Here is the same example for an STDIO MCP Server:
from mcp import StdioServerParameters
from crewai_tools import MCPServerAdapter
serverparams = StdioServerParameters(
command="uvx",
args=["--quiet", "pubmedmcp@0.1.3"],
env={"UV_PYTHON": "3.12", **os.environ},
)
try:
mcp_server_adapter = MCPServerAdapter(serverparams)
tools = mcp_server_adapter.tools
# tools is now a list of CrewAI Tools matching 1:1 with the MCP server's tools
agent = Agent(..., tools=tools)
task = Task(...)
crew = Crew(..., agents=[agent], tasks=[task])
crew.kickoff(...)
# ** important ** don't forget to stop the connection
finally:
mcp_server_adapter.stop()
And finally the same thing but for an SSE MCP Server:
from mcp import StdioServerParameters
from crewai_tools import MCPServerAdapter
serverparams = {"url": "http://localhost:8000/sse"}
try:
mcp_server_adapter = MCPServerAdapter(serverparams)
tools = mcp_server_adapter.tools
# tools is now a list of CrewAI Tools matching 1:1 with the MCP server's tools
agent = Agent(..., tools=tools)
task = Task(...)
crew = Crew(..., agents=[agent], tasks=[task])
crew.kickoff(...)
# ** important ** don't forget to stop the connection
finally:
mcp_server_adapter.stop()
Considerations & Limitations
Staying Safe with MCP
Always make sure that you trust the MCP Server before using it. Using an STDIO server will execute code on your machine. Using SSE is still not a silver bullet with many injection possible into your application from a malicious MCP server.
Limitations
- At this time we only support tools from MCP Server not other type of primitives like prompts, resources...
- We only return the first text output returned by the MCP Server tool using
.content[0].text
Why Use CrewAI Tools?
- Simplicity & Flexibility: Easy-to-use yet powerful enough for complex workflows.
- Rapid Integration: Seamlessly incorporate external services, APIs, and databases.
- Enterprise Ready: Built for stability, performance, and consistent results.
Contribution Guidelines
We welcome contributions from the community!
- Fork and clone the repository.
- Create a new branch (
git checkout -b feature/my-feature). - Commit your changes (
git commit -m 'Add my feature'). - Push your branch (
git push origin feature/my-feature). - Open a pull request.
Developer Quickstart
pip install crewai[tools]
Development Setup
- Install dependencies:
uv sync - Run tests:
uv run pytest - Run static type checking:
uv run pyright - Set up pre-commit hooks:
pre-commit install
Support and Community
Join our rapidly growing community and receive real-time support:
Build smarter, faster, and more powerful AI solutions—powered by CrewAI Tools.
