clawhub/docs/skill-format.md

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Skill folder format, required files, allowed file types, limits.	Publishing skills Debugging publish/sync failures

Skill format

On disk

A skill is a folder.

Required:

• SKILL.md (or skill.md)

Optional:

• any supporting text-based files (see “Allowed files”)
• .clawhubignore (ignore patterns for publish/sync, legacy .clawdhubignore)
• .gitignore (also honored)

Local install metadata (written by the CLI):

• <skill>/.clawhub/origin.json (legacy .clawdhub)

Workdir install state (written by the CLI):

• <workdir>/.clawhub/lock.json (legacy .clawdhub)

SKILL.md

• Markdown with optional YAML frontmatter.
• The server extracts metadata from frontmatter during publish.
• description is used as the skill summary in the UI/search.

Frontmatter metadata

Skill metadata is declared in the YAML frontmatter at the top of your SKILL.md. This tells the registry (and security analysis) what your skill needs to run.

Basic frontmatter

---
name: my-skill
description: Short summary of what this skill does.
version: 1.0.0
---

Runtime metadata (metadata.openclaw)

Declare your skill's runtime requirements under metadata.openclaw (aliases: metadata.clawdbot, metadata.clawdis).

---
name: my-skill
description: Manage tasks via the Todoist API.
metadata:
  openclaw:
    requires:
      env:
        - TODOIST_API_KEY
      bins:
        - curl
    primaryEnv: TODOIST_API_KEY
---

Full field reference

Field	Type	Description
requires.env	string[]	Environment variables your skill expects.
requires.bins	string[]	CLI binaries that must all be installed.
requires.anyBins	string[]	CLI binaries where at least one must exist.
requires.config	string[]	Config file paths your skill reads.
primaryEnv	string	The main credential env var for your skill.
always	boolean	If true, skill is always active (no explicit install needed).
skillKey	string	Override the skill's invocation key.
emoji	string	Display emoji for the skill.
homepage	string	URL to the skill's homepage or docs.
os	string[]	OS restrictions (e.g. ["macos"], ["linux"]).
install	array	Install specs for dependencies (see below).
nix	object	Nix plugin spec (see README).
config	object	Clawdbot config spec (see README).

Install specs

If your skill needs dependencies installed, declare them in the install array:

metadata:
  openclaw:
    install:
      - kind: brew
        formula: jq
        bins: [jq]
      - kind: node
        package: typescript
        bins: [tsc]

Supported install kinds: brew, node, go, uv.

Why this matters

ClawHub's security analysis checks that what your skill declares matches what it actually does. If your code references TODOIST_API_KEY but your frontmatter doesn't declare it under requires.env, the analysis will flag a metadata mismatch. Keeping declarations accurate helps your skill pass review and helps users understand what they're installing.

Example: complete frontmatter

---
name: todoist-cli
description: Manage Todoist tasks, projects, and labels from the command line.
version: 1.2.0
metadata:
  openclaw:
    requires:
      env:
        - TODOIST_API_KEY
      bins:
        - curl
    primaryEnv: TODOIST_API_KEY
    emoji: "\u2705"
    homepage: https://github.com/example/todoist-cli
---

Allowed files

Only “text-based” files are accepted by publish.

• Extension allowlist is in packages/schema/src/textFiles.ts (TEXT_FILE_EXTENSIONS).
• Content types starting with text/ are treated as text; plus a small allowlist (JSON/YAML/TOML/JS/TS/Markdown/SVG).

Limits (server-side):

• Total bundle size: 50MB.
• Embedding text includes SKILL.md + up to ~40 non-.md files (best-effort cap).

Slugs

• Derived from folder name by default.
• Must be lowercase and URL-safe: ^[a-z0-9][a-z0-9-]*$.

Versioning + tags

• Each publish creates a new version (semver).
• Tags are string pointers to a version; latest is commonly used.