skilllint
Static analysis linter for AI agent plugins, skills, and agents — for Claude Code, Cursor, Codex, and any agentskills.io-compatible platform.
What it does
skilllint validates the structure and content of AI agent files: plugins, skills, agents, and commands. It catches broken references, missing frontmatter, oversized skills, invalid hook configurations, and more — before they cause silent failures at runtime.
$ skilllint check plugins/my-plugin
plugins/my-plugin/skills/my-skill/SKILL.md
SK006 Token count 14823 exceeds recommended limit of 8192
plugins/my-plugin/agents/my-agent.md
NR001 Namespace reference 'other-plugin:some-skill' — plugin directory not found
2 errors in 2 files
Installation
pip install skilllint
Or with uv:
uv add skilllint # add to a project
uv tool install skilllint # install as a global tool
Requires Python 3.11–3.14.
Quick start
# Validate a plugin directory
skilllint check plugins/my-plugin
# Validate a single skill file
skilllint check plugins/my-plugin/skills/my-skill/SKILL.md
# Validate everything and show a summary
skilllint check --show-summary plugins/
# Auto-fix issues where possible
skilllint check --fix plugins/my-plugin
# Count tokens in any markdown file
skilllint check --tokens-only .claude/CLAUDE.md
Exit codes: 0 = all checks passed · 1 = validation errors · 2 = usage error
GitHub Action
Use bitflight-devops/skilllint as a GitHub Action to validate skills, plugins, and agents in any repository.
Replace X.Y.Z in the examples with the release you intend to pin. The Action
ref and the version input pin the Action and the installed package
independently.
- uses: bitflight-devops/skilllint@vX.Y.Z
with:
paths: "plugins/"
platform: "claude-code"
version: "X.Y.Z"
show-summary: "true"
Full input reference
| Input | Description | Default |
|---|---|---|
paths |
Space-separated paths to validate | . |
platform |
Platform adapter: claude-code, cursor, codex; omit to validate each selected file with every matching adapter |
(matching adapters) |
fix |
Auto-fix issues where possible | false |
check-only |
Validate only, do not auto-fix | false |
verbose |
Show detailed output including info messages | false |
no-color |
Disable color output | true |
tokens-only |
Output only the integer token count | false |
show-progress |
Show per-file PASSED/FAILED status | false |
show-summary |
Show summary panel at the end | true |
filter |
Glob pattern to restrict files within a directory | (none) |
filter-type |
File type filter: skills, agents, commands |
(all) |
version |
skilllint version to install (latest or 1.2.3) |
latest |
python-version |
Python version to use | 3.12 |
Outputs
| Output | Description |
|---|---|
result |
passed when exit code is 0; failed for any non-zero exit code |
exit-code |
Raw exit code: 0 = pass · 1 = errors · 2 = usage error |
inspected-count |
Number of files inspected by skilllint |
findings |
Distinct finding codes emitted by skilllint |
tool-python |
Python runtime used by the installed skilllint tool |
tool-version |
Version reported by the installed skilllint tool |
Example: fail the CI on validation errors
name: Validate skills
on: [push, pull_request]
jobs:
skilllint:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- name: Lint skills and plugins
uses: bitflight-devops/skilllint@vX.Y.Z
with:
paths: "plugins/ .claude/"
platform: "claude-code"
version: "X.Y.Z"
show-summary: "true"
verbose: "false"
Example: report results without blocking
- name: Lint skills and plugins
id: lint
uses: bitflight-devops/skilllint@vX.Y.Z
with:
paths: "plugins/"
version: "X.Y.Z"
continue-on-error: true
- name: Print result
run: echo "skilllint result=${{ steps.lint.outputs.result }}"
Pre-commit hook
Add to .pre-commit-config.yaml, replacing X.Y.Z with the release you intend to pin:
repos:
- repo: https://github.com/bitflight-devops/skilllint
rev: vX.Y.Z
hooks:
- id: skilllint
Contributor quality checks (local)
Run this sequence before pushing:
# Auto-fix hooks first (whitespace, pypfmt, oxlint/oxfmt, ruff --fix, etc.)
uv run prek run --all-files
uv run pytest
Platform support
skilllint ships with adapters for three platforms and supports third-party adapters via Python entry points:
| Platform | Adapter ID | Bundled |
|---|---|---|
| Claude Code | claude-code |
✓ |
| Cursor | cursor |
✓ |
| OpenAI Codex | codex |
✓ |
| OpenCode, Gemini, and others | — | via entry points |
Restrict validation to one platform:
skilllint check --platform claude-code plugins/my-plugin
Runtime rule reference
The installed runtime owns the active rule catalog, severity, platform scope, fixability, and rule documentation. Query it directly instead of relying on a copied table in this README:
skilllint rules
skilllint rule SK006
This keeps rule additions, retirements, and metadata changes synchronized with the executable that will perform the scan.
CLI reference
Use the executable's help for the current command and option inventory:
skilllint --help
skilllint check --help
skilllint rules --help
skilllint rule --help
skilllint docs --help
See Usage and integrations for maintained workflows and configuration examples.
Vendor documentation cache
skilllint docs provides the project's offline-first authority cache. Query
the current command surface with skilllint docs --help; see
Vendor documentation cache for cache ownership,
lifecycle, integrity, and contributor guidance.
Suppressing warnings
Use a .skilllint.json file to suppress specific rule codes for a directory tree. Place the file at any level — skilllint walks up from each scanned file and uses the nearest config it finds.
{
"ignore": {
"": ["AS008"],
"skills/legacy": ["FM007", "SK006"]
}
}
Key format:
| Key | Scope |
|---|---|
"" (empty string) |
All files under this .skilllint.json |
"skills/legacy" |
Files whose path (relative to the config file) starts with that prefix |
Plugin-level suppression (inside a .claude-plugin/ plugin):
Place validator.json inside .claude-plugin/:
{
"ignore": {
"": ["PA001"],
"agents/generated": ["FM004", "FM007"]
}
}
The same key format applies. Plugin-level config takes priority over a .skilllint.json in a parent directory.
Third-party adapters
Register a custom platform adapter via Python entry points in your pyproject.toml:
[project.entry-points."skilllint.adapters"]
my-platform = "my_package.adapter:MyPlatformAdapter"
Your adapter must implement the AdapterProtocol interface from skilllint.adapters.protocol.
Links
License
MIT
1 maintainer
Metadata
1 maintainer
Release files for skilllint 1.20.5
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| skilllint-1.20.5.tar.gz | 1.2 MB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| skilllint-1.20.5-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 2.2 MB
Release files / skilllint-1.20.5.tar.gz
| Download URL | skilllint-1.20.5.tar.gz |
|---|---|
| Size | 1.2 MB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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BLAKE2b-256 checksum How to use checksums |
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Yes |
| Uploaded via |
uv/0.12.21 {"installer":{"name":"uv","version":"0.12.21","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}
|
Release files / skilllint-1.20.5-py3-none-any.whl
| Download URL | skilllint-1.20.5-py3-none-any.whl |
|---|---|
| Size | 1.0 MB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
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Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
uv/0.12.21 {"installer":{"name":"uv","version":"0.12.21","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}
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