builtin-skills SKILL.md skillB
builtin-skills from charmbracelet/crush is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add charmbracelet/crush/builtin-skills@git:20260426.b9fdf72Pins git:20260426.b9fdf72 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- charmbracelet/crush
- Path
.agents/skills/builtin-skills/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260426.b9fdf72, committed Apr 26, 2026
- First version recorded
- Apr 16, 2026
- Size
- 1,866 bytes
- Repository stars
- 29,003
- License
- a license file GitHub does not identify
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
# Builtin Skills Crush embeds skills directly into the binary via `internal/skills/builtin/`. These are always available without user configuration. ## How It Works - Each skill lives in `internal/skills/builtin/<skill-name>/SKILL.md`. - The tree is embedded at compile time via `//go:embed builtin/*` in `internal/skills/embed.go`. - `DiscoverBuiltin()` walks the embedded FS, parses each `SKILL.md`, and sets paths with the `crush://skills/` prefix (e.g., `crush://skills/jq/SKILL.md`). - The View tool resolves `crush://` paths from the embedded FS, not disk. - User skills with the same name override builtins (last occurrence wins in `Deduplicate()`). ## Adding a New Builtin Skill 1. Create `internal/skills/builtin/<skill-name>/SKILL.md` with YAML frontmatter (`name`, `description`) and markdown instructions. The directory name must match the `name` field. 2. No extra wiring needed — `//go:embed builtin/*` picks up new directories automatically. 3. Add a test assertion in `TestDiscoverBuiltin` in `internal/skills/skills_test.go` to verify discovery. 4. Build and test: `go build . && go test ./internal/skills/...` ## Existing Builtin Skills …
Read the whole file at its exact version.
How to install
mdr add charmbracelet/crush/builtin-skills@sha256:890dde16f8f3eb3cThe line at the top of this page pins the label git:20260426.b9fdf72, 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_me5m772t2uokpxaw)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Apr 16, 2026 and Apr 26, 2026, about one every 5 days. Its first recorded version is graded A and its latest B.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260426.b9fdf72 latest | 2026-04-26 | b9fdf72 | 1,866 B | B | view · diff |
| git:20260420.0a86d5f | 2026-04-20 | 0a86d5f | 1,613 B | A | view · diff |
| git:20260416.3773b23 | 2026-04-16 | 3773b23 | 1,649 B | A | view |
Audit of the latest version
- fail: Frontmatter declares a description
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Size between 200 bytes and 200 KB (1866 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
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
charmbracelet/crush · 29,003 stars · license a license file GitHub does not identify · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_me5m772t2uokpxaw GET https://markdownregistry.com/api/v1/resolve?ref=charmbracelet/crush/builtin-skills GET https://markdownregistry.com/api/v1/blob/890dde16f8f3eb3cac4ac5e428ab2f5448af94d6c7ba834a2d277cb8b4dcc941
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.