Semgrep Mcp Server

What is MCP?

MCP, or Multi-Component Platform, is a server designed to use Semgrep for scanning code to find security vulnerabilities. It acts as a powerful tool for developers and security professionals, helping them ensure the integrity and safety of their codebases by detecting potential security issues early in the development process.

Features of MCP

• Security Scanning: MCP uses Semgrep's capabilities to scan code for various security vulnerabilities, assisting teams in maintaining secure coding practices.
• User-Friendly Interface: The platform provides an intuitive interface that simplifies the scanning process, making it accessible for users of all skill levels.
• Integration with CI/CD: MCP can be integrated into Continuous Integration and Continuous Deployment (CI/CD) pipelines, allowing for automated security checks as part of the development workflow.
• Customizable Rules: Users can define custom rules tailored to their specific security needs, enhancing the effectiveness of the scanning process.
• Real-Time Feedback: The platform offers immediate feedback on code vulnerabilities, enabling developers to address issues quickly.

How to Use MCP

1. Set Up Your Environment: Start by installing MCP on your server or local machine. Follow the installation instructions provided in the documentation.
2. Configure Your Project: Create a new project within MCP and set up the necessary settings, including the programming languages and frameworks you are using.
3. Define Scanning Rules: Use the built-in rules or create custom rules that reflect your organization's security policies.
4. Run Scans: Start a scan on your codebase. MCP will analyze the code and identify any vulnerabilities based on the defined rules.
5. Review Results: After the scan is complete, review the results to understand the vulnerabilities detected. The platform will provide detailed information about each issue.
6. Remediate Vulnerabilities: Address the identified vulnerabilities in your code. Use the feedback provided by MCP to guide your remediation efforts.
7. Integrate into CI/CD: For ongoing security assurance, integrate MCP into your CI/CD pipeline to automate scanning with each code change.

Frequently Asked Questions

What programming languages does MCP support?

MCP supports a wide range of programming languages, including but not limited to Python, JavaScript, Java, and Go. Check the documentation for a complete list of supported languages.

Is MCP open-source?

Yes, MCP is an open-source project, allowing users to contribute to its development and customize it according to their needs.

How can I report a vulnerability found in MCP?

If you find a vulnerability in MCP itself, please report it through the project's issue tracker on GitHub. Provide detailed information to help the maintainers address the issue quickly.

Can I use MCP for commercial projects?

Absolutely! MCP is designed for both personal and commercial use, making it a versatile tool for developers and organizations alike.

Where can I find more information about MCP?

For more information, visit the official MCP website at mcp.semgrep.ai or check the GitHub repository for documentation and updates.

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Semgrep MCP Server

A Model Context Protocol (MCP) server for using Semgrep to scan code for security vulnerabilities. Secure your vibe coding! 😅

Model Context Protocol (MCP) is a standardized API for LLMs, Agents, and IDEs like Cursor, VS Code, Windsurf, or anything that supports MCP, to get specialized help, get context, and harness the power of tools. Semgrep is a fast, deterministic static analysis tool that semantically understands many languages and comes with over 5,000 rules. 🛠️

[!NOTE] This beta project is under active development. We would love your feedback, bug reports, feature requests, and code. Join the #mcp community Slack channel!

Contents

• Semgrep MCP Server
  • Contents
  • Getting started
    • Cursor
    • ChatGPT
    • Hosted Server
      • Cursor
  • Demo
  • API
    • Tools
      • Scan Code
      • Understand Code
      • Cloud Platform (login and Semgrep token required)
      • Meta
    • Prompts
    • Resources
  • Usage
    • Standard Input/Output (stdio)
      • Python
      • Docker
    • Streamable HTTP
      • Python
      • Docker
    • Server-sent events (SSE)
      • Python
      • Docker
  • Semgrep AppSec Platform
  • Integrations
    • Cursor IDE
    • VS Code / Copilot
      • Manual Configuration
      • Using Docker
    • Windsurf
    • Claude Desktop
    • Claude Code
    • OpenAI
      • Agents SDK
    • Custom clients
      • Example Python SSE client
  • Contributing, community, and running from source
    • Similar tools 🔍
    • Community projects 🌟
    • MCP server registries

Getting started

Run the Python package as a CLI command using uv:

uvx semgrep-mcp # see --help for more options

Or, run as a Docker container:

docker run -i --rm ghcr.io/semgrep/mcp -t stdio 

Cursor

Example mcp.json

{
  "mcpServers": {
    "semgrep": {
      "command": "uvx",
      "args": ["semgrep-mcp"],
      "env": {
        "SEMGREP_APP_TOKEN": "<token>"
      }
    }
  }
}

Add an instruction to your .cursor/rules to use automatically:

Always scan code generated using Semgrep for security vulnerabilities

ChatGPT

1. Go to the Connector Settings page (direct link)
2. Name the connection Semgrep
3. Set MCP Server URL to https://mcp.semgrep.ai/sse
4. Set Authentication to No authentication
5. Check the I trust this application checkbox
6. Click Create

See more details at the official docs.

Hosted Server

[!WARNING] mcp.semgrep.ai is an experimental server that may break unexpectedly. It will rapidly gain new functionality.🚀

Cursor

1. Cmd + Shift + J to open Cursor Settings
2. Select MCP Tools
3. Click New MCP Server.

{
  "mcpServers": {
    "semgrep": {
      "type": "streamable-http",
      "url": "https://mcp.semgrep.ai/mcp"
    }
  }
}

Demo

<a href="https://www.loom.com/share/8535d72e4cfc4e1eb1e03ea223a702df"> <img style="max-width:300px;" src="https://cdn.loom.com/sessions/thumbnails/8535d72e4cfc4e1eb1e03ea223a702df-1047fabea7261abb-full-play.gif"> </a>

API

Tools

Enable LLMs to perform actions, make deterministic computations, and interact with external services.

Scan Code

• security_check: Scan code for security vulnerabilities
• semgrep_scan: Scan code files for security vulnerabilities with a given config string
• semgrep_scan_with_custom_rule: Scan code files using a custom Semgrep rule

Understand Code

• get_abstract_syntax_tree: Output the Abstract Syntax Tree (AST) of code

Cloud Platform (login and Semgrep token required)

• semgrep_findings: Fetch Semgrep findings from the Semgrep AppSec Platform API

Meta

• supported_languages: Return the list of languages Semgrep supports
• semgrep_rule_schema: Fetches the latest semgrep rule JSON Schema

Prompts

Reusable prompts to standardize common LLM interactions.

• write_custom_semgrep_rule: Return a prompt to help write a Semgrep rule

Resources

Expose data and content to LLMs

• semgrep://rule/schema: Specification of the Semgrep rule YAML syntax using JSON schema
• semgrep://rule/{rule_id}/yaml: Full Semgrep rule in YAML format from the Semgrep registry

Usage

This Python package is published to PyPI as semgrep-mcp and can be installed and run with pip, pipx, uv, poetry, or any Python package manager.

$ pipx install semgrep-mcp
$ semgrep-mcp --help

Usage: semgrep-mcp [OPTIONS]

  Entry point for the MCP server

  Supports both stdio and sse transports. For stdio, it will read from stdin
  and write to stdout. For sse, it will start an HTTP server on port 8000.

Options:
  -v, --version                Show version and exit.
  -t, --transport [stdio|sse]  Transport protocol to use (stdio or sse)
  -h, --help                   Show this message and exit.

Standard Input/Output (stdio)

The stdio transport enables communication through standard input and output streams. This is particularly useful for local integrations and command-line tools. See the spec for more details.

Python

semgrep-mcp

By default, the Python package will run in stdio mode. Because it's using the standard input and output streams, it will look like the tool is hanging without any output, but this is expected.

Docker

This server is published to Github's Container Registry (ghcr.io/semgrep/mcp)

docker run -i --rm ghcr.io/semgrep/mcp -t stdio

By default, the Docker container is in SSE mode, so you will have to include -t stdio after the image name and run with -i to run in interactive mode.

Streamable HTTP

Streamable HTTP enables streaming responses over JSON RPC via HTTP POST requests. See the spec for more details.

By default, the server listens on 127.0.0.1:8000/mcp for client connections. To change any of this, set FASTMCP_* environment variables. The server must be running for clients to connect to it.

Python

semgrep-mcp -t streamable-http

By default, the Python package will run in stdio mode, so you will have to include -t streamable-http.

Docker

docker run -p 8000:0000 ghcr.io/semgrep/mcp

Server-sent events (SSE)

[!WARNING] The MCP communiity considers this a legacy transport portcol and is really intended for backwards compatibility. Streamable HTTP is the recommended replacement.

SSE transport enables server-to-client streaming with Server-Send Events for client-to-server and server-to-client communication. See the spec for more details.

By default, the server listens on 127.0.0.1:8000/sse for client connections. To change any of this, set FASTMCP_* environment variables. The server must be running for clients to connect to it.

Python

semgrep-mcp -t sse

By default, the Python package will run in stdio mode, so you will have to include -t sse.

Docker

docker run -p 8000:0000 ghcr.io/semgrep/mcp -t sse

Semgrep AppSec Platform

Optionally, to connect to Semgrep AppSec Platform:

1. Login or sign up
2. Generate a token from Settings
3. Add the token to your environment variables:

   • CLI (export SEMGREP_APP_TOKEN=<token>)

   • Docker (docker run -e SEMGREP_APP_TOKEN=<token>)

   • MCP config JSON

    "env": {
      "SEMGREP_APP_TOKEN": "<token>"
    }

[!TIP] Please reach out for support if needed. ☎️

Integrations

Cursor IDE

Add the following JSON block to your ~/.cursor/mcp.json global or .cursor/mcp.json project-specific configuration file:

{
  "mcpServers": {
    "semgrep": {
      "command": "uvx",
      "args": ["semgrep-mcp"]
    }
  }
}

See cursor docs for more info.

VS Code / Copilot

Click the install buttons at the top of this README for the quickest installation.

Manual Configuration

Add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open User Settings (JSON).

{
  "mcp": {
    "servers": {
      "semgrep": {
        "command": "uvx",
        "args": ["semgrep-mcp"]
      }
    }
  }
}

Optionally, you can add it to a file called .vscode/mcp.json in your workspace:

{
  "servers": {
    "semgrep": {
      "command": "uvx",
        "args": ["semgrep-mcp"]
    }
  }
}

Using Docker

{
  "mcp": {
    "servers": {
      "semgrep": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "ghcr.io/semgrep/mcp",
          "-t",
          "stdio"
        ]
      }
    }
  }
}

See VS Code docs for more info.

Windsurf

Add the following JSON block to your ~/.codeium/windsurf/mcp_config.json file:

{
  "mcpServers": {
    "semgrep": {
      "command": "uvx",
      "args": ["semgrep-mcp"]
    }
  }
}

See Windsurf docs for more info.

Claude Desktop

Here is a short video showing Claude Desktop using this server to write a custom rule.

Add the following JSON block to your claude_desktop_config.json file:

{
  "mcpServers": {
    "semgrep": {
      "command": "uvx",
      "args": ["semgrep-mcp"]
    }
  }
}

See Anthropic docs for more info.

Claude Code

claude mcp add semgrep uvx semgrep-mcp

See Claude Code docs for more info.

OpenAI

See the offical docs:

• https://platform.openai.com/docs/mcp
• https://platform.openai.com/docs/guides/tools-remote-mcp

Agents SDK

async with MCPServerStdio(
    params={
        "command": "uvx",
        "args": ["semgrep-mcp"],
    }
) as server:
    tools = await server.list_tools()

See OpenAI Agents SDK docs for more info.

Custom clients

Example Python SSE client

See a full example in examples/sse_client.py

from mcp.client.session import ClientSession
from mcp.client.sse import sse_client


async def main():
    async with sse_client("http://localhost:8000/sse") as (read_stream, write_stream):
        async with ClientSession(read_stream, write_stream) as session:
            await session.initialize()
            results = await session.call_tool(
                "semgrep_scan",
                {
                    "code_files": [
                        {
                            "filename": "hello_world.py",
                            "content": "def hello(): print('Hello, World!')",
                        }
                    ]
                },
            )
            print(results)

[!TIP] Some client libraries want the URL: http://localhost:8000/sse and others only want the HOST: localhost:8000. Try out the URL in a web browser to confirm the server is running, and there are no network issues.

See official SDK docs for more info.

Contributing, community, and running from source

[!NOTE] We love your feedback, bug reports, feature requests, and code. Join the #mcp community Slack channel!

See CONTRIBUTING.md for more info and details on how to run from the MCP server from source code.

Similar tools 🔍

• semgrep-vscode - Official VS Code extension
• semgrep-intellij - IntelliJ plugin

Community projects 🌟

• semgrep-rules - The official collection of Semgrep rules
• mcp-server-semgrep - Original inspiration written by Szowesgad and stefanskiasan

MCP server registries

• Glama

<a href="https://glama.ai/mcp/servers/@semgrep/mcp"> <img width="380" height="200" src="https://glama.ai/mcp/servers/4iqti5mgde/badge" alt="Semgrep Server MCP server" /> </a>

• MCP.so

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