semgrep-rule-creator SKILL.md skillA
semgrep-rule-creator from trailofbits/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add trailofbits/skills/semgrep-rule-creator@git:20260610.5577119Pins git:20260610.5577119 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- trailofbits/skills
- Path
plugins/semgrep-rule-creator/skills/semgrep-rule-creator/SKILL.md- Versions recorded
- 5
- Latest version
- git:20260610.5577119, committed Jun 10, 2026
- First version recorded
- Jan 28, 2026
- Size
- 7,320 bytes
- Repository stars
- 8,043
- License
- CC-BY-SA-4.0
Creates custom Semgrep rules for detecting security vulnerabilities, bug patterns, and code patterns. Use when writing Semgrep rules or building custom static analysis detections.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Semgrep Rule Creator Create production-quality Semgrep rules with proper testing and validation. ## When to Use **Ideal scenarios:** - Writing Semgrep rules for specific bug patterns - Writing rules to detect security vulnerabilities in your codebase - Writing taint mode rules for data flow vulnerabilities - Writing rules to enforce coding standards ## When NOT to Use Do NOT use this skill for: - Running existing Semgrep rulesets - General static analysis without custom rules (use `static-analysis` skill) ## Rationalizations to Reject When writing Semgrep rules, reject these common shortcuts: - **"The pattern looks complete"** → Still run `semgrep --test --config <rule-id>.yaml <rule-id>.<ext>` to verify. Untested rules have hidden false positives/negatives. - **"It matches the vulnerable case"** → Matching vulnerabilities is half the job. Verify safe cases don't match (false positives break trust). - **"Taint mode is overkill for this"** → If data flows from user input to a dangerous sink, taint mode gives better precision than pattern matching. …
Read the whole file at its exact version.
How to install
mdr add trailofbits/skills/semgrep-rule-creator@sha256:6ca2e3b8520ed20aThe line at the top of this page pins the label git:20260610.5577119, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ytd7bkg3yfpmett7)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jan 28, 2026 and Jun 10, 2026, about one every 33 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260610.5577119 latest | 2026-06-10 | 5577119 | 7,320 B | A | view · diff |
| git:20260428.debfb29 | 2026-04-28 | debfb29 | 7,315 B | A | view · diff |
| git:20260316.8655937 | 2026-03-16 | 8655937 | 7,343 B | A | view · diff |
| git:20260130.7934f0b | 2026-01-30 | 7934f0b | 6,707 B | A | view · diff |
| git:20260128.09b6ebe | 2026-01-28 | 09b6ebe | 8,403 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (7320 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
trailofbits/skills · 8,043 stars · license CC-BY-SA-4.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ytd7bkg3yfpmett7 GET https://markdownregistry.com/api/v1/resolve?ref=trailofbits/skills/semgrep-rule-creator GET https://markdownregistry.com/api/v1/blob/6ca2e3b8520ed20af1b0879b7cab318832fcbe89c19c17a9fa347a45a9f28913
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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