pikku-cli

name	pikku-cli
description	Use when building CLI commands with Pikku. Covers wireCLI, pikkuCLICommand, subcommands, options, parameters, custom renderers, and nested command groups. TRIGGER when: code uses wireCLI/pikkuCLICommand, user asks about CLI commands, terminal tools, command-line interface, or adding subcommands. DO NOT TRIGGER when: user asks about the pikku CLI tool itself (use pikku-info) or HTTP endpoints (use pikku-http).
installGroups	["core"]

Pikku CLI Wiring

Agent Operating Procedure

Use this skill as an execution checklist, not reference material.

1. Discover before editing. Prefer OpenCode tools such as pikku-meta when available; otherwise run the relevant pikku meta ... --json command and inspect only the focused output you need.
2. Identify the source files that own the behavior. Do not start by reading generated output, .pikku, node_modules, vendored packages, or broad build artifacts.
3. Make the smallest source change that satisfies the task. Keep generated files generated, and avoid hand-editing SDKs, schema output, or typegen.
4. Validate with the narrowest relevant command first, then run pikku-verify or pikku all when functions, wirings, schemas, or generated clients may have changed.
5. If validation fails, fix the source cause and rerun validation. Do not paper over generated errors by editing generated files.

Wire Pikku functions as CLI commands with parameters, options, subcommands, and custom terminal renderers.

Before You Start

pikku info functions --verbose   # See existing functions and their types
pikku info tags --verbose        # Understand project organization

See pikku-concepts for the core mental model.

API Reference

wireCLI(config)

import { wireCLI } from '@pikku/core/cli'

wireCLI({
  program: string,              // Program name (e.g. 'todos')
  options?: {                   // Global options
    [key: string]: {
      description: string,
      short?: string,           // Single char alias (e.g. 'v')
      default?: any,
    }
  },
  render?: PikkuCLIRender,      // Default renderer for all commands
  commands: {
    [name: string]: PikkuCLICommand | {
      description: string,
      subcommands: { [name: string]: PikkuCLICommand }
    }
  },
})

pikkuCLICommand(config)

import { pikkuCLICommand } from '#pikku'

pikkuCLICommand({
  parameters?: string,          // Positional args (e.g. '<text>', '<username> <email>')
  func: PikkuFunc,              // Business logic function
  description?: string,
  render?: PikkuCLIRender,      // Custom output renderer
  options?: {
    [key: string]: {
      description: string,
      short?: string,
      default?: any,
      choices?: string[],       // Restrict to values
    }
  },
})

pikkuCLIRender(fn)

import { pikkuCLIRender } from '@pikku/core/cli'

const renderer = pikkuCLIRender<OutputType>((services, data) => {
  // Format and print output to terminal
  console.log(data)
})

Usage Patterns

Basic Commands

wireCLI({
  program: 'todos',
  commands: {
    add: pikkuCLICommand({
      parameters: '<text>',
      func: createTodo,
      description: 'Add a new todo',
      render: todoRenderer,
      options: {
        priority: {
          description: 'Set priority',
          short: 'p',
          default: 'normal',
          choices: ['low', 'normal', 'high'],
        },
      },
    }),
    list: pikkuCLICommand({
      func: listTodos,
      description: 'List all todos',
      render: todosRenderer,
      options: {
        completed: {
          description: 'Show completed only',
          short: 'c',
          default: false,
        },
      },
    }),
  },
})
// Usage: todos add "Buy milk" -p high
// Usage: todos list -c

Nested Subcommands

wireCLI({
  program: 'app',
  options: {
    verbose: { description: 'Verbose output', short: 'v', default: false },
  },
  commands: {
    greet: pikkuCLICommand({
      parameters: '<name>',
      func: greetUser,
      render: greetRenderer,
    }),

    user: {
      description: 'User management',
      subcommands: {
        create: pikkuCLICommand({
          parameters: '<username> <email>',
          func: createUser,
          render: userRenderer,
          options: {
            admin: { description: 'Admin role', short: 'a', default: false },
          },
        }),
        list: pikkuCLICommand({
          func: listUsers,
          render: usersRenderer,
          options: {
            limit: { description: 'Max results', short: 'l' },
          },
        }),
      },
    },
  },
})
// Usage: app greet Alice
// Usage: app user create bob [e-mail] -a
// Usage: app user list -l 10
// Usage: app -v user list

Custom Renderers

A renderer receives (services, data) where data is the func's output. Set render on wireCLI as the program-wide default; set render on a pikkuCLICommand to override it for that command.

const todoRenderer = pikkuCLIRender<{ todo: Todo }>((_services, { todo }) => {
  console.log(`✓ Created: ${todo.text} (priority: ${todo.priority})`)
})

wireCLI({
  program: 'todos',
  render: jsonRenderer, // default for all commands
  commands: {
    add: pikkuCLICommand({ func: createTodo, render: todoRenderer }), // overrides jsonRenderer
  },
})

The func's input is the positional parameters plus options, merged (e.g. parameters: '<username> <email>' + an admin option → func input { username, email, admin }).

Complete Example

For a full functions + renderers + nested-subcommand wiring walkthrough, see references/complete-example.md.