jackspeak 4.x

Use jackspeak v4 to declare command-line fields, parse an explicit argument array, validate parsed values, and render usage documentation.

For

jackspeak@4.2.3

Verified

2026-09-08, 3 examples executed

Package

@modootoday/pmcp-jackspeak@4.0.0

What it covers

• Use this skill when
• Core parsing shape
• Field kinds
• Validation and generated documentation
• Headings, descriptions, and fields
• Environment integration
• Common mistakes
• Not covered

One example from this skill

This is the skill's own text, not a summary of it. It runs: that is what verifying means here.

import { strict as assert } from 'node:assert'
import { jack } from 'jackspeak'

const parser = jack({ envPrefix: 'FOO' })
  .flag({
    foo: { description: 'another boolean', short: 'f' },
  })
  .optList({
    'ip-addrs': {
      description: 'addresses to ip things',
      delim: ',',
      default: ['127.0.0.1'],
    },
  })

const { positionals, values } = parser.parse([
  'some',
  'positional',
  '--ip-addrs',
  '192.168.0.1',
  '--ip-addrs',
  '1.1.1.1',
  '--foo',
])

assert.deepEqual(positionals, ['some', 'positional'])
assert.equal(values.foo, true)
assert.deepEqual(values['ip-addrs'], ['192.168.0.1', '1.1.1.1'])

What it did in the sandbox

Verifying this skill meant installing the package and running code against it with no route out. This is what happened, quoted from the run. The full ledger lists every package examined, including the ones that never became a skill.

• prepare: tshy && bash build.sh the package
• prepare: tshy && bash build.sh the package

Getting it

With a subscription:

npx -y @modootoday/pmcp login
npx -y @modootoday/pmcp install @modootoday/pmcp-jackspeak

It installs as a dev dependency of your project, and the MCP server finds it there like any other skill.