Semgrep MCP Server

What is Semgrep MCP Server about?

Enables automated static analysis through the Model Context Protocol, allowing AI assistants and development tools to invoke Semgrep for security checks, AST generation, and rule look‑ups without leaving the chat or editor environment.

How to use Semgrep MCP Server?

Run the server – install the Python package (semgrep-mcp) via uvx, pipx, or Docker and start it with the desired transport (stdio, streamable-http, or sse).
Configure a client – add an MCP server entry to Cursor, VS Code, Claude, or any MCP‑compatible client, pointing to the command (uvx semgrep-mcp) or Docker container.
Invoke tools – LLMs call tools such as semgrep_scan, security_check, or get_abstract_syntax_tree to analyze code, retrieve findings, or fetch rule schemas.

Key features of Semgrep MCP Server

Multiple transports: support for stdio, streamable‑HTTP, and Server‑Sent Events.
Rich tool set: security scanning, custom‑rule scanning, AST extraction, language list, rule schema lookup, and cloud platform findings.
Cross‑IDE integration: ready‑made configuration snippets for Cursor, VS Code, Windsurf, Claude Desktop/Code, and OpenAI agents.
Docker image: official ghcr.io/semgrep/mcp container for easy deployment.
Extensible prompts: reusable prompts for writing custom Semgrep rules.

Use cases of Semgrep MCP Server

AI‑assisted code review – let ChatGPT, Claude, or other agents automatically scan PRs for vulnerabilities.
IDE tooling – developers receive real‑time security feedback inside Cursor or VS Code without installing separate extensions.
Custom rule generation – agents can guide users to create bespoke Semgrep rules via the provided prompt.
Enterprise compliance – integrate with the Semgrep AppSec Platform to pull existing findings and enforce policies.

FAQ

Q: Do I need a Semgrep token? A: Only for cloud‑platform features (fetching findings). Set SEMGREP_APP_TOKEN in the environment or Docker run command.

Q: Which transport should I pick? A: Use stdio for local CLI integrations, streamable-http for HTTP‑based clients, and sse only for legacy support.

Q: Can I run the server without Docker? A: Yes – install the Python package via pipx, uv, or poetry and launch with semgrep-mcp.

Q: How do I add the server to VS Code? A: Add a JSON block to your user settings or workspace .vscode/mcp.json specifying the command (uvx semgrep-mcp) and optionally Docker args.

Q: Is the repository still active? A: The standalone repo is deprecated; continued development occurs in the main semgrep repository and the official binary.

⚠️ The Semgrep MCP server has been moved from a standalone repo to the main `semgrep` repository! ⚠️

This repository has been deprecated, and further updates to the Semgrep MCP server will be made via the official semgrep binary.

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!

Semgrep MCP Server

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

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

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

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

Demo

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

semgrep_findings: Fetch Semgrep findings from the Semgrep AppSec Platform API

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:

Login or sign up
Generate a token from Settings
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"]
    }
  }
}

cursor MCP settings

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:

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": [
                        {
                            "path": "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

MCP.so

Made with ❤️ by the Semgrep Team

Semgrep MCP Server