Semgrep Guardian: AI coding agent security plugin

Semgrep Guardian integrates natively with AI coding agents like Claude Code and Cursor to catch security issues before they ship. It bundles the Semgrep MCP server, Hooks, and Skills into a single install, and scans every file an agent generates using Semgrep Code, Supply Chain, and Secrets. When findings are detected, the agent is prompted to regenerate code until Semgrep returns clean results or you choose to dismiss them. Claude Code uses Semgrep’s hosted remote server and authenticates through OAuth, so developers don’t need to install or run the Semgrep CLI. Every other supported IDE runs Semgrep through a locally installed CLI. See Authentication for details on sign-in and enterprise rollout. The plugin uses each IDE’s native hook or MCP system:

Claude Code: hooks and plugins
Codex: MCP
Cursor: hooks and MCP
GitHub Copilot (Visual Studio, JetBrains, Xcode, Eclipse): MCP
Kiro: MCP
VS Code: MCP
Devin (Windsurf): Cascade hooks

This guide covers setup for each of the preceding products listed, but the plugin works with any MCP client.

Prerequisites

A Semgrep account

Authentication

How you sign in depends on which IDE you use. Claude Code (remote scans): The plugin handles authentication through OAuth. Each developer completes a one-time browser login when they first use the plugin. Semgrep refreshes access tokens automatically, so developers rarely need to sign in again. Other IDEs: These integrations run Semgrep through a locally installed CLI. Each developer signs in with semgrep login, which opens a browser-based login flow. See Install the Semgrep CLI.

CLI and OAuth credentials

Guardian stores credentials in two local files under ~/.semgrep/:

settings.yml: written when you sign in through semgrep login or set an API token manually. This is the same file the Semgrep CLI uses.
guardian.yml: written when you sign in through OAuth in the remote Claude Code plugin.

If you are already logged in through semgrep login, Guardian can use the credentials from settings.yml. For the remote Claude Code plugin, Guardian checks for OAuth credentials in guardian.yml first. If OAuth credentials are present, Guardian uses them instead of any API token in settings.yml. At startup, Guardian fetches its default authentication method from Semgrep’s remote server. OAuth is currently the default for users who are not yet signed in. This setting is global and not configurable per user. If you are switching from a local CLI setup to the remote Claude Code plugin, keep in mind that an existing OAuth session in guardian.yml takes precedence over CLI credentials in settings.yml. If scans run under a different account than you expect, check which file contains active credentials. Use semgrep logout to remove CLI credentials from settings.yml. To sign in with the legacy API-token method in Claude Code, ask the Guardian MCP to log in to Semgrep using the legacy method.

Semgrep may disable API-token login for Guardian in the future, but there are no definite plans as of now.

Enterprise rollout

Shared API tokens and service accounts are not recommended for Guardian. Each developer should authenticate individually through OAuth for Claude Code or semgrep login for local CLI integrations. For Claude Code with remote scans, OAuth helps Semgrep associate activity with the correct user and avoids the risks of shared credentials. Semgrep discourages sharing app or API tokens across a team because:

Revoking a shared token affects every user who depends on it.
Shared credentials are rate-limited as a single user, which can throttle scans when many developers run Guardian concurrently.

If you set an API token in ~/.semgrep/settings.yml, Guardian can use it when no OAuth session exists in guardian.yml. Semgrep does not recommend this pattern for enterprise rollouts.

Connect to your IDE

Claude Code uses Semgrep’s hosted remote server by default, so you do not need to install the Semgrep CLI locally.

Start a Claude Code instance:

claude

Open the plugin manager:

/plugin

Go to Discover, search for Semgrep, and click Install.

Tell Claude to load the plugin:

/reload-plugins

Start a new session in Claude to begin the OAuth login flow:

/clear

The plugin registers a post-tool hook so Claude Code scans every file it writes. Learn more about Claude Code plugins and hooks.

Run Semgrep Guardian locally

The remote server is the recommended default. If you need to run Semgrep locally instead, you can install the local plugin from the semgrep/guardian-local repo.

Install the Semgrep CLI.

Start a Claude Code instance:

claude

Add the Semgrep marketplace:

/plugin marketplace add semgrep/guardian-local

Install the plugin from the marketplace:

/plugin install semgrep@semgrep-marketplace

Tell Claude to load the plugin:

/reload-plugins

Set up the plugin:

/setup-semgrep-plugin

Install the Semgrep CLI.

Update your ~/.codex/config.toml file and paste the following:

[mcp_servers.semgrep]
command = "semgrep"
args = ["mcp"]

Codex does not expose a post-write hook, so Semgrep tools are surfaced through MCP and invoked when the agent calls them. Learn more about Codex MCP configuration.

Install the Semgrep CLI.

Find Semgrep in the Cursor Plugin Marketplace, or open Cursor > ⌘⇧J > Plugins. Search “Semgrep” and click Add to Cursor.

Restart Cursor to apply configuration.

In Cursor’s chat, run the /setup-semgrep-plugin skill to finish wiring up the plugin.The plugin uses Cursor hooks (afterFileEdit and stop) to scan code as the agent writes it, and exposes Semgrep tools through Cursor MCP.

Use this tab for GitHub Copilot in Visual Studio, JetBrains IDEs, Xcode, or Eclipse. (For Copilot in VS Code, use the VS Code tab.)

Install the Semgrep CLI.

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

Follow your IDE’s instructions for where to put this entry: Extending Copilot Chat with MCP servers covers Visual Studio, JetBrains, Xcode, and Eclipse.

Restart your IDE and open Copilot Chat. Semgrep tools become available in Agent mode.

Copilot does not expose a post-write hook, so Semgrep tools are invoked when the agent calls them through MCP.

Install the Semgrep CLI.

Add the Semgrep MCP server to VS Code. Create .vscode/mcp.json in your workspace (or run the MCP: Open User Configuration command from the Command Palette for a user-wide entry) and paste the following:

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

Reload VS Code. Semgrep tools become available in the Copilot Chat Agent mode.

VS Code does not expose a post-write hook today, so Semgrep tools are invoked when the agent calls them through MCP. Learn more about adding and managing MCP servers in VS Code.

Install the Semgrep CLI.

Create a hooks.json file at ~/.codeium/windsurf/hooks.json and paste the following configuration:

{
  "hooks": {
    "post_write_code": [
      {
        "command": "semgrep mcp -k post-tool-cli-scan -a windsurf",
        "show_output": true
      }
    ]
  }
}

Restart Windsurf to apply hook configuration.

The post_write_code event fires after Cascade writes or modifies any file. Learn more about Windsurf Cascade hooks.

Kiro uses your locally installed Semgrep CLI to run Semgrep on your machine, so install the Semgrep CLI first. Clicking the box below opens Kiro directly so you can add the server; it will not open a new browser tab.

Alternatively, follow the Kiro MCP docs and add this file to your .kiro/settings/mcp.json:

{
  "mcpServers": {
    "semgrep": {
      "command": "semgrep",
      "args": ["mcp"],
      "env": {
        "SEMGREP_APP_TOKEN": "${SEMGREP_TOKEN}"
      }
    }
  }
}

See Kiro docs for more info.

Install the Semgrep CLI, then add the Semgrep MCP Server to your IDE. Semgrep provides sample configuration information that you can use as a starting point. Refer to your IDE’s documentation for specific details on where to add the MCP server configuration.If your IDE supports a post-write or post-tool hook, point it at semgrep mcp -k post-tool-cli-scan -a <ide-name> to scan generated code automatically. The Windsurf tab above shows this pattern.

Install the Semgrep CLI

This section applies only if you use an IDE other than Claude Code, or if you run the local Claude Code plugin. Claude Code’s default remote plugin handles authentication through OAuth and does not require a local CLI.

Install the Semgrep CLI using Homebrew, pipx, or uv. This requires Python 3.10 or later (the Semgrep CLI needs it at runtime regardless of how it was installed):

# install using Homebrew
brew install semgrep

# or, install using pipx (https://pipx.pypa.io/stable/how-to/install-pipx/)
pipx install semgrep

# or, install using uv (https://docs.astral.sh/uv/)
uv tool install semgrep

Verify that you’ve installed the latest version of Semgrep:

semgrep --version

semgrep login && semgrep install-semgrep-pro

semgrep login launches a browser window. You can also use the activation link printed in the terminal.

Enterprise deployment guide

To roll out Semgrep Guardian across an organization, standardize the install so every developer’s agent picks up the plugin automatically instead of relying on each developer to install it by hand.

Use your agent’s built-in enterprise controls

Most coding agents let you pin an approved marketplace or plugin for your whole team. This is the simplest way to make Guardian available (or required) everywhere:

Claude Code: Require marketplaces for your team
Cursor: Team marketplaces

Deploy through a mobile device management (MDM) platform for more granularity

Deploy through your MDM platform to scope rollout by device group, or to combine Guardian with other managed configuration deployed via your MDM. Anthropic maintains a set of MDM deployment examples and best practices that cover managed settings for macOS (.plist and .mobileconfig profiles via Jamf, Kandji, and similar) and Windows (PowerShell file deployment or ADMX/registry policy via Intune and Group Policy), along with how to verify that managed settings are applied.

Get help with a custom rollout

Reach out if you want help building something custom for your MDM or agent fleet. You can find us in Semgrep’s #mcp Slack community or check out our support options.

Additional resources

Semgrep’s #mcp Slack community
The Semgrep MCP server repo on GitHub

Get started

Set up and deploy scans

Scan and triage

Semgrep Multimodal

Semgrep Community Edition

References

Semgrep Guardian: AI coding agent security plugin

Prerequisites

Authentication

CLI and OAuth credentials

Enterprise rollout

Connect to your IDE

Install the Semgrep CLI

Enterprise deployment guide

Use your agent’s built-in enterprise controls

Deploy through a mobile device management (MDM) platform for more granularity

Get help with a custom rollout

Additional resources

​Prerequisites

​Authentication

​CLI and OAuth credentials

​Enterprise rollout

​Connect to your IDE

​Install the Semgrep CLI

​Enterprise deployment guide

​Use your agent’s built-in enterprise controls

​Deploy through a mobile device management (MDM) platform for more granularity

​Get help with a custom rollout

​Additional resources

Prerequisites

Authentication

CLI and OAuth credentials

Enterprise rollout

Connect to your IDE

Install the Semgrep CLI

Enterprise deployment guide

Use your agent’s built-in enterprise controls

Deploy through a mobile device management (MDM) platform for more granularity

Get help with a custom rollout

Additional resources