frontmatter-guard SKILL.md skillA
frontmatter-guard from garrytan/gbrain is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add garrytan/gbrain/frontmatter-guard@v1.1.0Pins v1.1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- garrytan/gbrain
- Path
skills/frontmatter-guard/SKILL.md- Versions recorded
- 8
- Latest version
- v1.1.0, committed Oct 28, 2026
- First version recorded
- Aug 11, 2026
- Size
- 15,628 bytes
- Repository stars
- 31,587
- License
- MIT
Validate and auto-repair YAML frontmatter on brain pages. Catches malformed pages before they enter the brain (missing closing ---, nested quotes, slug mismatches, null bytes, empty frontmatter, YAML parse failures), explains files sync holds instead of importing, and drives the previewed `gbrain repair frontmatter` fix. Wraps the `gbrain frontmatter` CLI for agent-driven workflows.
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
# Frontmatter Guard Skill > **Convention:** see `skills/conventions/quality.md` for citation rules; this skill is structural validation, not citation auditing. ## Contract This skill guarantees: - Every brain page is scanned against the eight canonical frontmatter validation classes - Mechanical errors (nested quotes, missing closing `---`, null bytes, slug mismatch) are auto-repairable on demand with `.bak` backups - Validation logic is shared with `gbrain doctor`'s `frontmatter_integrity` subcheck — single source of truth - Reports per source (gbrain is multi-source since v0.18.0); never silently audits the wrong root - Files sync holds are explained from their hold record (code, reason, key, line, fix) and fixed only through a previewed, hash-bound repair the user approved ## Why This Exists Brain pages pile up over months. Agents write them with malformed frontmatter: - Missing closing `---` (entity detector bugs) - Unstructured YAML in meeting pages (ingestion bugs) - Slug mismatches (path renames not propagated) - Null bytes (binary corruption from copy-paste accidents) - Nested double quotes in titles (`title: "Alice "Ace" Example"`) …
Read the whole file at its exact version.
How to install
mdr add garrytan/gbrain/frontmatter-guard@sha256:a64ab4281d3a7d05The line at the top of this page pins the label v1.1.0, 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_izbzwmkc3dvheagq)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 8 versions of this file, between Aug 11, 2026 and Oct 28, 2026, about one every 11 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.1.0 latest | 2026-10-28 | f93052f | 15,628 B | A | view · diff |
| v1.1.0 | 2026-10-14 | 44dcdf3 | 15,500 B | A | view · diff |
| v1.1.0 | 2026-10-07 | 590bb9a | 15,221 B | A | view · diff |
| v1.1.0 | 2026-10-04 | f75a79d | 15,220 B | A | view · diff |
| v1.0.0 | 2026-10-03 | 2343669 | 10,478 B | A | view · diff |
| v1.0.0 | 2026-09-15 | f1fbdfb | 9,803 B | A | view · diff |
| v1.0.0 | 2026-08-16 | df4feda | 9,669 B | A | view · diff |
| v1.0.0 | 2026-08-11 | d35c9c9 | 9,666 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 (15628 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
garrytan/gbrain · 31,587 stars · license MIT · pushed 2026-11-06 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_izbzwmkc3dvheagq GET https://markdownregistry.com/api/v1/resolve?ref=garrytan/gbrain/frontmatter-guard GET https://markdownregistry.com/api/v1/blob/a64ab4281d3a7d05b596b9c56e5c63c9c45c229e4a43f4270850682335402af6
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.