skillit

skillit — Compile-time generator of AI agent skills from your codebase.

Inline docs, CLI definitions, config schemas, and examples compile into progressively disclosed SKILL.md files that any LLM can discover. Integrated with TypeDoc, with support for conventional repo docs, and plugins for Docusaurus and VitePress provided for what code can't cover.

MCP Servers (orthogonal workflow)

skillit can also generate skills from any live MCP server, even when the server was not authored with skillit.

This is separate from the TypeDoc/docs extraction flow above: it introspects MCP tools/resources/prompts over stdio or HTTP and emits a progressive-disclosure SKILL.md. You can render:

native MCP launch instructions (mcp: frontmatter in SKILL.md, which tells MCP-capable agents how to start/connect to the server), or
CLI-proxy launch instructions for non-MCP harnesses (such as mcpc/fastmcp).

# Inspect any running or launchable MCP server and generate skills
npx skillit mcp extract \
  --command "npx -y @modelcontextprotocol/server-filesystem /tmp" \
  --out ./skills

# Optional: install non-default CLI invocation adapters
npm install --save-dev @skillit/target-mcpc @skillit/target-fastmcp

# Emit CLI-proxy invocation variants for non-MCP agents
npx skillit mcp extract \
  --command "npx -y @modelcontextprotocol/server-filesystem /tmp" \
  --invocation cli:mcpc \
  --invocation cli:fastmcp \
  --out ./skills

For server package authors, skillit mcp bundle can be run in your build to ship pre-generated skills with your MCP package.

See packages/mcp/README.md for install, extract, bundle, config-file batch mode (mcp.json / claude_desktop_config.json), and programmatic API details.

Bootstrap (recommended): `/skillit-bootstrap`

The primary way to create or improve a skill is the /skillit-bootstrap Claude Code skill (bundled with @skillit/client). It runs the deterministic generate → audit loop and lets the agent enrich your repo's source (JSDoc, README, examples, package.json) until the skill hits its grade target — you never hand-edit a SKILL.md.

# Install the bundled skill into your project (one time)
cp -R node_modules/@skillit/client/skills/skillit-bootstrap .claude/skills/

# Then, in Claude Code:
/skillit-bootstrap --source cli --program ./dist/cli.js#program
/skillit-bootstrap --source typedoc

Supported sources this release: cli and typedoc. For config / mcp, use skillit refine (below); slash-command support for those lands in a later phase. The CLI commands (skillit gen, skillit audit --json, skillit refine) remain for headless/CI use.

Init: detect → install

skillit init wires a project up. It detects the project's nature and installs the matching @skillit/* package with your package manager, then points you at skillit gen to produce the skill. It does not generate or refine — those are separate, explicit commands (skillit gen, skillit refine).

# Auto-detects nature and package manager, installs the right @skillit package
npx skillit init

# Force the source kind
npx skillit init --source mcp

# Config source is built in (no install) — init just points at `skillit gen`
npx skillit init --source config --config-type ./src/config.ts#MyConfig

Detection:

Nature — commander / yargs dep → cli; @modelcontextprotocol/sdk → mcp; otherwise a plain TS library → typedoc. Override with --source.
Package — cli → @skillit/cli, mcp → @skillit/mcp, typedoc → typedoc-plugin-skillit. The config source is built into the CLI (no install).
Package manager — pnpm-lock.yaml → pnpm, yarn.lock → yarn, else npm.

If the install step fails, init prints the exact add command and stops.

Flag	Default	Description
`--source <cli\|mcp\|typedoc>`	auto	Override project-nature detection
`--config-type <file#export>`	—	Config type entry (config source)

Gen: deterministic skill generation

skillit gen (re)generates the skill from the current source — no install, no model, no network. It is the deterministic, side-effect-free generate primitive: the same source always yields the same skill. Run it after init, and again whenever you change the documented source (JSDoc, config type, README).

# Generate from the auto-detected source into skills/
npx skillit gen

# CLI source with an explicit commander program entry
npx skillit gen --source cli --program ./dist/cli.js#program

# Config source
npx skillit gen --source config --config-type ./src/config.ts#MyConfig

# Generate into a custom directory (default: skills)
npx skillit gen --out docs/skills

This release implements gen for the cli and config sources; mcp and typedoc generation land in a later phase (use skillit mcp extract for MCP servers meanwhile).

Flag	Default	Description
`--source <cli\|config>`	auto	Source kind (cli/config this release)
`--program <file#export>`	—	Commander program entry (cli source)
`--config-type <file#export>`	—	Config type entry (config source)
`--out <dir>`	`skills`	Output directory for the generated skill

Audit: score + findings as JSON

skillit audit runs the same audit + judge the refine loop uses and prints the result. With --json it emits the full AuditResult + score estimate, plus a resolved on-disk location for each improvement target — the machine-readable read-surface an agent (or CI) can act on without re-deriving anything.

# Human summary (grade + severity counts)
npx skillit audit --source cli

# Full machine-readable report
npx skillit audit --source config --config-type ./src/config.ts#MyConfig --json

Like gen, audit supports the cli and config sources this release; mcp / typedoc land in a later phase.

Flag	Default	Description
`--source <cli\|config>`	auto	Source kind (cli/config this release)
`--program <file#export>`	—	Commander program entry (cli source)
`--config-type <file#export>`	—	Config type entry (config source)
`--json`	off	Emit the full audit + estimate as JSON

Refine: autonomous annotation loop

skillit refine runs an audit → draft → review loop that iteratively improves the useWhen / avoidWhen annotations in your generated skills. On each pass it asks an LLM to evaluate the current guidance, proposes improvements, and applies them — no manual editing required.

Refine is source-aware. It auto-detects the source from the installed @skillit/* package, or you can choose explicitly:

# CLI source — writes guidance back into the *Options interface JSDoc
npx skillit refine --source cli --program ./dist/cli.js#program

# MCP source (see modes below)
npx skillit refine --source mcp --mcp ./mcp.json

For the cli source, refine writes annotations into the JSDoc of your typed *Options interface (e.g. GenerateOptions), correlated to each command's flags.

Two modes depending on whether you own the server's source:

Build mode — for TypeScript MCP servers you own. refine writes annotations directly into source as _meta fields on each server.tool(...) call:

server.tool(
  'read_file',
  {
    description: 'Read a file',
    _meta: { useWhen: 'After listing a directory to inspect a specific file' }
  },
  schema,
  handler
);

# Auto-detected when @modelcontextprotocol/sdk appears in package.json
npx skillit mcp refine

# Explicit
npx skillit mcp refine --mode build

Runtime mode — for any MCP server, including ones you don't own. refine writes an overlay JSON file that extract / bundle merges at render time:

# Auto-detected when --mcp points to mcp.json / claude_desktop_config.json
npx skillit mcp refine --mcp ~/.config/claude/mcp.json

# Refine only a subset of tools
npx skillit mcp refine --mode runtime --mcp ./mcp.json --items filesystem,github

Auto-detection checks for an SDK dependency (build signal) and a runtime config path (runtime signal). When both are present the command is ambiguous — pass --mode explicitly.

Key flags:

Flag	Default	Description
`--source <cli\|mcp\|typedoc>`	auto	Refine source (auto-detected from installed package)
`--program <file#export>`	—	Commander program entry (cli source)
`--mode build\|runtime`	auto	Override auto-detection
`--mcp <path>`	—	Path to `mcp.json` or `claude_desktop_config.json`
`--source-glob <glob>`	`*/.ts`	Glob for TypeScript files to scan (build mode)
`--max-iterations <n>`	`5`	Iteration cap for the audit→draft→review loop
`--items <n>`	`5`	Work items per iteration
`--model-client <kind>`	`api`	Model backend: `api` (ANTHROPIC_API_KEY) or a CLI: `claude` / `codex` / `copilot`
`--model-cli-timeout <ms>`	`120000`	Per-call timeout for CLI model backends

CLI model backends. Instead of the Anthropic API, refine (and init) can drive the loop through an already-authenticated agent CLI — --model-client claude, codex, or copilot. The drafter/reviewer prompts are identical; only the transport changes. claude maps the drafter/reviewer split to Sonnet/Opus via --model; codex/copilot use their configured default model. Each CLI must be installed and authenticated. Note: copilot prioritizes a GH_TOKEN/GITHUB_TOKEN environment variable over its /login credential — if that token lacks the "Copilot Requests" permission, unset it so copilot uses your login. On Windows the CLIs are launched through the shell to support .cmd shims; the prompt is always piped via stdin (never passed as a command argument), so untrusted content never reaches the command line.

Why Inline?

When an agent updates your code, inline docs update atomically. There's no separate file to remember, no coordination problem, no drift. The agent edits ONE location and the truth propagates mechanically.

/**
 * Parse a configuration file.
 *
 * @useWhen
 * - Loading config from user-provided paths
 * - Dynamic config resolution at startup
 *
 * @pitfalls
 * - NEVER trust user paths without sanitization — resolves relative to cwd
 *
 * @param path Path to the config file
 * @returns Parsed and validated configuration
 */
export function loadConfig(path: string): Config { ... }

pnpm typedoc → the generated skill tells every LLM when to use this function, what to watch out for, and how to call it.

Quick Start by Project Type

TypeScript Library (most common)

pnpm add -D typedoc-plugin-skillit
pnpm typedoc

That's it. TypeDoc auto-discovers the plugin. Skills appear at skills/<package-name>/SKILL.md.

Monorepo

// typedoc.json
{
  "entryPointStrategy": "packages",
  "entryPoints": ["packages/*"],
  "plugin": ["typedoc-plugin-skillit"],
  "skillsPerPackage": true
}

One skill per package — each with its own SKILL.md, references, and config surfaces.

CLI Tool (commander/yargs)

import { extractCliSkill, writeCliSkill } from '@skillit/cli';

const skill = await extractCliSkill({
  program, // commander Program object
  metadata: { name: 'my-tool', keywords: ['build', 'deploy'] }
});

writeCliSkill(skill, {
  outDir: 'skills',
  installTargets: ['.claude/skills']
});

Introspects command definitions, correlates flags with typed *Options interfaces for JSDoc enrichment, surfaces CLI audit findings on skill.audit, and can install the generated skill plus bundled CLI guidance into agent discovery roots.

Library with Docs Site (VitePress)

// .vitepress/config.mts
import { defineConfig } from 'vitepress';
import { toSkills } from '@skillit/vitepress';

export default defineConfig({
  vite: {
    plugins: [toSkills({ skillsOutDir: 'skills' })]
  },
  themeConfig: { sidebar: [...] }
});

The VitePress plugin uses your sidebar for authoritative page ordering — no frontmatter heuristics.

Library with Docs Site (Docusaurus)

import { extractDocusaurusDocs } from '@skillit/docusaurus';

const docs = extractDocusaurusDocs({ projectRoot: '.' });
// Returns ExtractedDocument[] — merge into your skill

Reads _category_.json for folder labels and ordering. Excludes api/ and blog/ by default.

Library with Prose Docs (any framework)

// typedoc.json — opt-in alongside API extraction
{
  "plugin": ["typedoc-plugin-skillit"],
  "skillsIncludeDocs": true,
  "skillsDocsDir": "docs"
}

Scans docs/ directory for markdown files. Also picks up root-level docs (ARCHITECTURE.md, MIGRATION.md, TROUBLESHOOTING.md).

What Gets Extracted

Sources

Source	Extractor	What It Produces
TypeScript source + JSDoc	`typedoc-plugin-skillit`	API reference — functions, classes, types, enums, variables
`@useWhen` / `@avoidWhen` tags	TypeDoc plugin	Decision procedures in SKILL.md "When to Use"
`@pitfalls` tag	TypeDoc plugin	Anti-patterns in SKILL.md "Pitfalls"
`@remarks` tag	TypeDoc plugin	Expert knowledge in references
`@category` tag	TypeDoc plugin	Export grouping in Quick Reference + references
`@config` interfaces	TypeDoc plugin	Configuration tables in SKILL.md + references/config.md
Commander/yargs programs	`@skillit/cli`	CLI commands + flags in references/commands.md
`examples/` directory	`@skillit/core`	Linked to matching exports by import analysis
`docs/` directory	`@skillit/core` or VitePress/Docusaurus plugin	Prose docs as reference files
Root `.md` files	`@skillit/core`	ARCHITECTURE.md, MIGRATION.md, etc. as references
README.md	`@skillit/core`	Blockquote description, ## Features, ## Quick Start, ## Troubleshooting
package.json	TypeDoc plugin	Name, description, keywords, repository, license

Audit Checks

The documentation audit runs automatically during pnpm typedoc and reports issues at four severity levels:

Severity	What It Checks	CI Behavior
fatal	package.json description, 5+ keywords, README description, JSDoc on every export	Exit 1 (configurable)
error	@param prose, @returns on non-void, interface property JSDoc, at least one @example, repository URL	Exit 1 (configurable)
warning	@useWhen, @avoidWhen, @pitfalls presence, @remarks on complex functions, @category usage, README ## Features, README ## Troubleshooting	Exit 0 (logged)
alert	Generic keywords, @param restates type, trivial @example, verbose Quick Start	Exit 0 (logged)

Enable CI enforcement: "skillsAuditFailOnError": true

Generated Output

skills/<package-name>/
  SKILL.md                     # Discovery file (~200 tokens)
  references/
    functions.md               # Grouped by @category or source module
    types.md                   # Interfaces with properties, type aliases
    classes.md                 # With inheritance, methods, properties
    config.md                  # @config interfaces as option tables
    commands.md                # CLI commands with flags (from @skillit/cli)
    variables.md               # Exported constants
    examples.md                # From @example tags
    architecture.md            # From root ARCHITECTURE.md
    getting-started.md         # From docs/ pages
    ...                        # One file per doc page

Each reference file is token-budgeted independently (default 4000 tokens).

Packages

Package	Description
`typedoc-plugin-skillit`	Auto-discovery wrapper — just install, no config
`@skillit/core`	Types, renderer, audit engine, token budgeting, docs/examples scanning
`@skillit/typedoc`	TypeDoc plugin — API + config extraction from the reflection tree
`@skillit/cli`	Commander/yargs introspection + `--help` fallback + flag correlation
`@skillit/vitepress`	VitePress Vite plugin — sidebar-driven docs extraction
`@skillit/docusaurus`	Docusaurus adapter — `_category_.json` + docs scanning
`@skillit/mcp`	MCP extractor/bundler — introspect live servers and emit SKILL.md
`@skillit/target-mcp-protocol`	MCP-native invocation target adapter for rendered skills
`@skillit/target-mcpc`	CLI-proxy invocation adapter via `mcpc`
`@skillit/target-fastmcp`	CLI-proxy invocation adapter via Python `fastmcp` CLI

Configuration

{
  "plugin": ["typedoc-plugin-skillit"],
  "skillsOutDir": "skills",
  "skillsPerPackage": true,
  "skillsAudit": true,
  "blockTags": ["@useWhen", "@avoidWhen", "@pitfalls", "@config"]
}

Option	Default	Description
`skillsOutDir`	`"skills"`	Output directory for SKILL.md files
`skillsInstallTargets`	`[]`	Additional agent discovery directories to sync
`skillsPerPackage`	`true`	One skill per package in monorepos
`skillsMaxTokens`	`4000`	Max token budget per reference file
`skillsAudit`	`true`	Run documentation audit during generation
`skillsAuditFailOnError`	`false`	Fail build on fatal/error audit issues (for CI)
`skillsIncludeDocs`	`false`	Include prose docs from `docs/` directory
`llmsTxt`	`false`	Generate llms.txt and llms-full.txt

See the full options reference for all 14 options.

Examples

See the examples/ directory for runnable scripts:

basic-skill-generation.ts — generate a SKILL.md from an ExtractedSkill object
audit-and-fix.ts — run the documentation audit and print results
cli-extraction.ts — extract skills from a commander program
docs-scanning.ts — include prose docs alongside API skills

Case Study: PixiJS (47K stars)

We forked PixiJS and bootstrapped skillit to measure the before/after impact on generated skill quality, scored against the skill-judge rubric (120 points, 8 dimensions).

Results

Phase	Score	Grade	What Changed	Agent Cost
Install + generate	84/120	B-	`npm install typedoc-plugin-skillit && pnpm typedoc`	0 tokens
After JSDoc conventions	113/120	A	`@useWhen`/`@pitfalls` on 7 key classes (110 lines of JSDoc)	~80K tokens

B- → A with 110 lines of JSDoc annotations. The generator handles structure, progressive disclosure, config detection, and reference splitting automatically. The annotations add the expert knowledge — when to use each class, what to never do, and why.

What the agent wrote (110 lines, ~80K tokens)

// src/scene/sprite/Sprite.ts — added to existing JSDoc
/**
 * @useWhen
 * - Displaying images, texture regions, or sprite sheets
 * - You need fast batched rendering of many images
 * @avoidWhen
 * - Drawing dynamic shapes — use Graphics instead
 * - Rendering text — use Text or BitmapText
 * @pitfalls
 * - NEVER create Sprites from unloaded textures — always Assets.load() first
 * - NEVER use Sprite.from() in hot loops — it creates new textures each call
 */

Similar annotations on Application, Container, Graphics, Text, Assets, and AbstractRenderer. The @packageDocumentation block added 6 NEVER rules covering v8 migration pitfalls.

Generated output (224 reference files)

skills/pixi-js/
  SKILL.md (343 lines)
  references/
    classes/
      scene/                    # Per-class files + index.md
        container.md, sprite.md, graphics.md, ...
      rendering/                # 80+ renderer system classes
        abstractrenderer.md, webglrenderer.md, ...
      text/, assets/, events/, filters/, maths/, ...
    functions.md, types.md, config.md, variables.md
    architecture.md, scene-graph.md, render-loop.md
    performance-tips.md, garbage-collection.md
    v5-migration-guide.md ... v8-migration-guide.md

Fork: pradeepmouli/pixijs

Ecosystem

agentskills.io — the SKILL.md specification
skills.sh — skill registry and CLI (npx skills add)
llmstxt.org — the llms.txt specification

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 511 Commits
.changeset		.changeset
.claude/skills		.claude/skills
.github		.github
.vscode		.vscode
docs		docs
drafts		drafts
examples		examples
packages		packages
scripts		scripts
skills		skills
specs		specs
website		website
.env.example		.env.example
.eslintignore		.eslintignore
.gitattributes		.gitattributes
.gitignore		.gitignore
.lintstagedrc.json		.lintstagedrc.json
.oxfmtrc.json		.oxfmtrc.json
CHANGELOG.md		CHANGELOG.md
CLAUDE.md		CLAUDE.md
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
SECURITY.md		SECURITY.md
llms-full.txt		llms-full.txt
llms.txt		llms.txt
mcp.json		mcp.json
oxlintrc.json		oxlintrc.json
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
pnpm-workspace.yaml		pnpm-workspace.yaml
renovate.json		renovate.json
tsconfig.json		tsconfig.json
tsconfig.typedoc.json		tsconfig.typedoc.json
typedoc.json		typedoc.json
vitest.config.ts		vitest.config.ts

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skillit

MCP Servers (orthogonal workflow)

Bootstrap (recommended): /skillit-bootstrap

Init: detect → install

Gen: deterministic skill generation

Audit: score + findings as JSON

Refine: autonomous annotation loop

Why Inline?

Quick Start by Project Type

TypeScript Library (most common)

Monorepo

CLI Tool (commander/yargs)

Library with Docs Site (VitePress)

Library with Docs Site (Docusaurus)

Library with Prose Docs (any framework)

What Gets Extracted

Sources

Audit Checks

Generated Output

Packages

Configuration

Examples

Case Study: PixiJS (47K stars)

Results

What the agent wrote (110 lines, ~80K tokens)

Generated output (224 reference files)

Ecosystem

License

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Bootstrap (recommended): `/skillit-bootstrap`

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