WebQ

Tools for querying and validating Web Components against Custom Elements Manifest (CEM) files.

Packages

Package	Description
@webq/cli	CLI tool and MCP server for querying and validating CEM files
@webq/eslint	ESLint plugin for validating custom element HTML usage
schemas	JSON schemas for CEM, custom attributes, patterns, styles, and more

Quick Start

CLI

curl -fsSL https://raw.githubusercontent.com/blueprintui/webq/main/projects/cli/install.sh | bash

Or install via NodeJS:

npm install -g @webq/cli

# List all custom elements
webq element.list --path ./node_modules
# Get details for a specific element
webq element bp-button --path ./node_modules
# Validate HTML against CEM definitions
webq validate-html '<bp-button variant="primary">Click</bp-button>' --path ./node_modules

See the CLI README for the full command reference, configuration, and MCP tool documentation.

ESLint Plugin

npm install @webq/eslint --save-dev

// eslint.config.jsimporthtmlParserfrom'@html-eslint/parser';import{recommended}from'@webq/eslint';exportdefault[{files: ['**/*.html'],languageOptions: {parser: htmlParser},
...recommended({cem: './path/to/custom-elements.json'})}];

See the ESLint README for manual configuration and the full rule list.

MCP Server

WebQ can run as an MCP server, providing AI assistants with tools for querying element APIs and validating HTML.

Claude Code

webq setup-mcp
webq setup-skill

Cursor

Add to .cursor/mcp.json:

{
"mcpServers": {
"webq": {
"command": "webq",
"args": ["mcp", "--path", "./node_modules"]
}
}
}

Validation Rules

Both @webq/cli and @webq/eslint share the same 18 validation rules:

Rule	Severity	Description
no-unknown-element	error	Custom elements must exist in the manifest
no-unknown-attr	error	Attributes must be defined in the manifest
no-unknown-attr-value	error	Values must match defined type unions
no-unknown-event	error	Event bindings must match defined events
no-unknown-slot	error	Slot values must match defined slots
no-unknown-command	error	Commands must match defined commands
no-unknown-css-part	error	::part() selectors must match defined CSS parts
no-unknown-css-custom-property	error	CSS custom properties must match definitions
no-missing-required-child	error	Pattern root elements must have required children
no-missing-sibling-binding	error	Sibling trigger/target pairs must have matching bindings
no-deprecated-element	warn	Warn on deprecated elements
no-deprecated-attr	warn	Warn on deprecated attributes
no-deprecated-event	warn	Warn on deprecated events
no-deprecated-slot	warn	Warn on deprecated slots
no-deprecated-command	warn	Warn on deprecated commands
no-boolean-attr-value	warn	Warn when boolean attributes have explicit values
no-unknown-style-value	warn	var() references must match defined custom properties
no-unknown-custom-attr-value	warn	Custom attribute values must match definitions

Schemas

JSON schemas for validating manifest files are available in projects/schemas/:

Schema	Description
custom-elements	Per-component APIs (attributes, properties, events, slots, CSS)
custom-patterns	Compositional rules (parent/child, sibling relationships)
custom-attributes	Global HTML attributes (utility token-list attributes)
custom-styles	Global CSS custom properties and cascade layers
dtcg	Design Token Community Group token format
vscode-html	VSCode custom data format for HTML
vscode-css	VSCode custom data format for CSS

Development

bun install # Install all dependencies
bun run ci # Build + test all packages
bun run format # Check formatting (prettier)
bun run format:fix # Fix formatting

License

MIT