Yell

CLI Reference

Installation

npm install -g @yell/cli

Or use via npx:

npx yell --help

Commands

`yell validate`

Validate a YAML file against the schema:

yell validate input.yell.yaml

yell validate input.yell.yaml --registry ./components.yaml

Exit codes:

0 — valid
1 — invalid (errors printed to stderr)
2 — parse error

`yell render`

Render YAML to HTML:

yell render input.yell.yaml --out dist/index.html

yell render input.yell.yaml --registry ./components.yaml --pretty

`yell lint`

Check YAML for anti-patterns:

yell lint input.yell.yaml

yell lint input.yell.yaml --rules noInlineFunctions,maxDepth:5

Linter rules

Rule	Description	Default
`noInlineFunctions`	Block `onClick: () => ...`	error
`maxExpressionLength`	Max chars in an expression	100
`maxNestingDepth`	Max nesting depth	5
`noMutations`	Block `x = x + 1`	error
`allowedShowWhenOps`	Allowed operators in showWhen	`['==','!=','&&','\|\|','!','>','<']`

Fix mode

Auto-fix safe violations:

yell lint input.yell.yaml --fix

`yell build`

Build with import/include resolution:

yell build input.yell.yaml --out dist/

yell build input.yell.yaml --registry ./components.yaml --tokens ./tokens.yaml

`yell tokens`

Migrate token references:

yell tokens migrate --from old.yaml --to new.yaml input.yell.yaml

`yell ai`

Generate YAML from natural language:

yell ai "Create a login page with email and password"

yell ai "Create a dashboard" --registry ./components.yaml --model claude-3-5-sonnet

Global options

Option	Description
`--help`, `-h`	Show help
`--version`, `-v`	Show version
`--quiet`, `-q`	Suppress output
`--verbose`	Extra debug output

Configuration

Create a .yellrc file in your project root:

registry: ./components.yaml
tokens: ./tokens.yaml
rules:
  noInlineFunctions: error
  maxNestingDepth: 5
  maxExpressionLength: 100

Yell automatically loads .yellrc from the current directory.

Examples

Validate and render in CI

# .github/workflows/yell.yml
- name: Validate YAML
  run: yell validate . --recursive

- name: Build for production
  run: yell build ./src --out ./dist

Watch mode

yell build --watch

File changes trigger rebuild.