completion-script-generator

name	completion-script-generator
license	Apache-2.0
description	Generates shell completion scripts for CLI tools. Parses command structure from help output, commander/yargs configs, or manual specification. Produces completions for bash, zsh, and fish that follow each shell's conventions.
category	Backend & Infrastructure
tags	["cli","completion","bash","zsh","fish","shell"]
allowed-tools	["Read","Bash(*)","Glob","Grep","Write","Edit"]
pairs-with	[{"skill":"beautiful-cli-design","reason":"Completions are a core part of CLI UX — a beautiful CLI without completions is half-finished"},{"skill":"daemon-development","reason":"Long-running daemon CLIs benefit most from completions since users interact frequently"},{"skill":"devtool-documentation","reason":"Completions serve as executable documentation of available commands and flags"}]

Completion Script Generator

Generate shell completion scripts that make CLIs feel native. Parses existing command structure from source code, help output, or manual specification, then produces idiomatic completions for bash, zsh, and fish. Handles subcommands, flags with arguments, mutually exclusive options, file completions, and dynamic completions that query the tool at runtime.

When to Use

Use for:

• Adding tab completion to a CLI built with commander, yargs, clap, cobra, or argparse
• Generating completions from --help output when source code is unavailable
• Creating zsh completions with descriptions (the gold standard of shell completion UX)
• Implementing dynamic completions that call the CLI to list valid values at runtime
• Porting completions between shells (e.g., bash completions exist, need zsh and fish)
• Adding completions to a CLI as part of the install/setup experience

Do NOT use for:

• Building the CLI itself (use beautiful-cli-design)
• General shell scripting (this is specifically about completion registration)
• IDE/editor autocompletion (different system entirely)
• Prompt customization (use shell config skills)

---

Core Capabilities

1. Command Structure Extraction

Before generating completions, you need the command tree. Three extraction methods, from most to least reliable:

Method A: Parse Source Code (Best)

For Node.js CLIs using commander:

# Extract commands and options from commander program
grep -rn '\.command(' src/cli.ts | while read -r line; do
  cmd=$(echo "$line" | grep -oP "\.command\(['\"]([^'\"]+)" | sed "s/.*['\"]//")
  echo "COMMAND: $cmd"
done

grep -rn '\.option(' src/cli.ts | while read -r line; do
  flag=$(echo  | grep -oP  | sed )
  desc=$(  | grep -oP  |  -1)