chengjingfeng / semgrep

Lightweight static analysis for many languages. Find bug variants with patterns that look like source code.

Lightweight static analysis for many languages.
Find bugs and enforce code standards.

Semgrep is a fast, open-source, static analysis tool that finds bugs and enforces code standards at editor, commit, and CI time. Precise rules look like the code you’re searching; no more traversing abstract syntax trees, wrestling with regexes, or using a painful DSL. Code analysis is performed locally (code is not uploaded) and Semgrep runs on uncompiled code.

The Semgrep Registry has 1,000+ rules written by the Semgrep community covering security, correctness, and performance bugs. No need to DIY unless you want to.

Semgrep is used in production everywhere from one-person startups to multi-billion dollar companies; it’s the engine inside tools like NodeJsScan. See tools powered by Semgrep.

Semgrep is developed and commercially supported by r2c, a software security company. r2c’s hosted service, Semgrep App, lets organizations easily deploy in CI, manage rules across many projects, monitor the efficacy of code policy, and integrate with 3rd-party services. r2c offers free and paid hosted tiers (see pricing).

Language support

General availability

Go · Java · JavaScript · JSX · JSON · Python · Ruby · TypeScript · TSX

Beta & experimental

See supported languages for the complete list.

Getting started

To install Semgrep use Homebrew or pip, or run without installation via Docker:

# For macOS
$ brew install semgrep

# For Ubuntu/WSL/Linux/macOS
$ python3 -m pip install semgrep

# To try Semgrep without installation run via Docker
$ docker run --rm -v "${PWD}:/src" returntocorp/semgrep --help

Once installed, Semgrep can run with single rules or entire rulesets. Visit Running rules to learn more or try the following:

# Check for Python == where the left and right hand sides are the same (often a bug)
$ semgrep -e '$X == $X' --lang=py path/to/src

# Run the r2c-ci ruleset (with rules for many languages) on your own code!
$ semgrep --config=p/r2c-ci path/to/src

Visit Getting started to learn more.

Rule examples

Visit Rule examples for use cases and ideas. There is also an excellent interactive tutorial.

Use case	Semgrep rule
Ban dangerous APIs	Prevent use of exec
Search routes and authentication	Extract Spring routes
Enforce the use secure defaults	Securely set Flask cookies
Enforce project best-practices	Use assertEqual for == checks, Always check subprocess calls
Codify project-specific knowledge	Verify transactions before making them
Audit security hotspots	Finding XSS in Apache Airflow, Hardcoded credentials
Audit configuration files	Find S3 ARN uses
Migrate from deprecated APIs	DES is deprecated, Deprecated Flask APIs, Deprecated Bokeh APIs
Apply automatic fixes	Use listenAndServeTLS

Integrations

Visit Integrations to learn about Semgrep editor, commit, and CI integrations. When integrated into CI and configured to scan pull requests, Semgrep will only report issues introduced by that pull request; this lets you start using Semgrep without fixing or ignoring pre-existing issues!

Documentation

Browse the full Semgrep documentation on the website. If you’re new to Semgrep, check out Getting started or the interactive tutorial.

More

• Frequently asked questions (FAQs)
• Contributing
• Ask questions in the r2c Community Slack
• CLI reference and exit codes
• r2c YouTube channel with Semgrep presentation videos
• License (LGPL-2.1)

Upgrading

To upgrade, run the command below associated with how you installed Semgrep:

# Using Homebrew
$ brew upgrade semgrep

# Using pip
$ python3 -m pip install --upgrade semgrep

# Using Docker
$ docker pull returntocorp/semgrep:latest