---
title: "Semgrep Custom Rule Builder"
description: "Creates custom Semgrep SAST rules using the semgrep CLI and rule schema YAML format. Supports pattern-either, metavariable-regex, and taint-mode tracking for detecting framework-specific vulnerabilities in Python, Go, and JavaScript."
verification: "security_reviewed"
source: "https://github.com/semgrep/semgrep"
category:
  - "Code Quality & Review"
framework:
  - "MCP"
tool_ecosystem:
  github_repo: "semgrep/semgrep"
  github_stars: 14794
---

# Semgrep Custom Rule Builder

Creates custom Semgrep SAST rules using the semgrep CLI and rule schema YAML format. Supports pattern-either, metavariable-regex, and taint-mode tracking for detecting framework-specific vulnerabilities in Python, Go, and JavaScript.

## Installation

Choose whichever fits your setup:

1. Copy this skill folder into your local skills directory.
2. Clone the repo and symlink or copy the skill into your agent workspace.
3. Add the repo as a git submodule if you manage shared skills centrally.
4. Install it through your internal provisioning or packaging workflow.
5. Download the folder directly from GitHub and place it in your skills collection.

## Source

- [Agent Skill Exchange](https://agentskillexchange.com/skills/semgrep-custom-rule-builder-3/)