arg

Positional argument schema factory.

Entry point for defining args on a command. Use arg.<kind>() to create an ArgBuilder, then chain modifiers and pass the result to command().arg(name, builder).

Four kinds are available:

• arg.string() — raw string (most common)

• arg.number() — parsed to number, errors on NaN

• arg.enum(values) — constrained to listed literals

• arg.custom(fn) — arbitrary parse function, infers return type

• Import: @kjanat/dreamcli

• Export kind: constant

• Declared in: src/core/schema/arg.ts

• Source link: packages/dreamcli/src/core/schema/arg.ts:668

Signatures

const arg: ArgFactory;

Examples

import { command, arg } from '@kjanat/dreamcli';

command('deploy')
  .arg('target', arg.string().env('DEPLOY_TARGET').describe('Where to deploy'))
  .arg('port', arg.number().env('PORT').default(3000))
  .action(({ args }) => {
    console.log(`Deploying to ${args.target} on port ${args.port}`);
  });

// $ mycli deploy production 8080    → target='production', port=8080
// $ DEPLOY_TARGET=staging mycli deploy → target='staging', port=3000

Related Examples

• Basic single-command CLI. - examples/standalone/basic.ts
• Interactive prompts with config file fallback. - examples/standalone/interactive.ts
• Mixed machine-readable JSON and human-readable side-channel output. - examples/standalone/json-mode.ts
• Middleware patterns: auth guard, request timing, error handling. - examples/standalone/middleware.ts
• Multi-command CLI with nested command groups (git-like). - examples/standalone/multi-command.ts
• Testing examples using @kjanat/dreamcli/testkit. - examples/standalone/testing.ts

See Also

• Examples overview
• Example Hover
• API overview
• @kjanat/dreamcli