packx

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Bundle code context for AI. ALWAYS use --limit 49k unless user explicitly requests otherwise. Use for creating shareable code bundles and preparing context for LLMs.

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[Memory and Context Management]

When & Why to Use This Skill

Packx is a high-performance CLI tool designed to optimize how developers provide code context to AI models. It solves the 'context window' problem by intelligently bundling, filtering, and compressing source code into AI-ready formats. By enforcing safe token limits and offering advanced features like comment stripping and Git integration, it ensures that LLMs receive the most relevant information without exceeding capacity or wasting tokens.

Use Cases

  • Context Optimization for LLMs: Automatically bundle relevant source files while stripping comments and minifying code to fit maximum logic into a single AI prompt.
  • AI-Driven Code Reviews: Use Git integration (--diff or --staged) to provide AI agents with only the changed code for targeted feedback and PR description generation.
  • Deep Debugging: Follow imports and include related files (tests, stories) to give the AI a complete architectural view of a specific bug or feature.
  • Large Project Indexing: Split massive codebases into manageable, numbered chunks using the multi-output feature to stay within token budgets while maintaining project-wide context.
  • Workflow Automation: Create shareable code bundles in XML or Markdown formats to quickly sync project state with AI coding assistants or external collaborators.
namepackx
descriptionBundle code context for AI. ALWAYS use --limit 49k unless user explicitly requests otherwise. Use for creating shareable code bundles and preparing context for LLMs.

PACKX - AI Context Bundler

Bundle and filter code files for AI context.

CRITICAL: Always Use --limit 49k

MANDATORY: Every packx command MUST include --limit 49k unless the user explicitly requests a different limit. This is non-negotiable. Using 49k instead of 50k provides a safety buffer.

# CORRECT - always include --limit 49k
packx --limit 49k -c src/
packx --limit 49k -s "pattern" -i "*.ts" -c

# WRONG - never omit the limit
packx -c src/                        # NO! Missing --limit
packx -s "pattern" -i "*.ts" -c      # NO! Missing --limit

Prerequisites

packx --version    # Verify installed
npm install -g packx   # If not installed

Standard Command Pattern

packx --limit 49k [filters] [output] [paths]

Always start with --limit 49k, then add filters and output options.

CLI Reference

Token Budget (Required)

# Standard (default for all commands)
packx --limit 49k -c src/

# Only use different limits if user explicitly requests
packx --limit 32k -c src/            # User said "32k"
packx --limit 128k -c src/           # User said "large context"

# Split into chunks if content exceeds limit (requires -o for numbered files)
packx -M 49k -o context src/         # Creates context-1.xml, context-2.xml

Limit formats: 8k=8,000 | 32K=32,768 | 50000=50,000

Search & Filter

# Find files containing text
packx --limit 49k -s "TODO" -c
packx --limit 49k -s "useState" -i "*.tsx" -c
packx --limit 49k -s "error" -s "warning" -c

# Exclude content
packx --limit 49k -S "test" -S "mock" -c

# Filter by glob patterns
packx --limit 49k -i "*.ts" -c
packx --limit 49k -i "src/**/*.tsx" -c
packx --limit 49k -x "*.test.ts" -x "*.spec.ts" -c

# Regex patterns
packx --limit 49k -R -s "function\s+\w+" -c

# Case-sensitive
packx --limit 49k -C -s "Error" -c

Git Integration

packx --limit 49k --staged -c        # Staged files
packx --limit 49k --diff -c          # Changed from main
packx --limit 49k --dirty -c         # Modified/untracked

Processing Options

# Strip comments (reduces tokens)
packx --limit 49k --strip-comments -c src/

# Minify (remove empty lines)
packx --limit 49k --minify -c src/

# Both (maximum token efficiency)
packx --limit 49k --strip-comments --minify -c src/

# Context lines around matches
packx --limit 49k -s "TODO" -l 5 -c

# Follow imports
packx --limit 49k --follow-imports src/index.ts -c

# Related files (tests, stories)
packx --limit 49k -r src/utils.ts -c

Output Options

# Copy to clipboard (most common)
packx --limit 49k -c src/

# Save to file (use --stdout > to avoid WriteFile hook limits)
packx --limit 49k --stdout src/ > context.md

# Output formats
packx --limit 49k -f xml -c src/         # XML (default)
packx --limit 49k -f markdown -c src/    # Markdown
packx --limit 49k -f plain -c src/       # Plain text
packx --limit 49k -f jsonl -c src/       # JSONL

IMPORTANT: Always use --stdout > <file> instead of --output <file> to avoid triggering WriteFile hook size limits on large bundles.

Preview (Check Before Packing)

# Preview matching files without packing
packx --limit 49k --preview src/
packx --limit 49k -s "pattern" --preview

Interactive Mode

packx --limit 49k -I src/            # Interactive selection
packx --limit 49k --no-interactive src/  # Scripting mode

Controls: Tab=preview focus | PgUp/PgDn=scroll | Enter=confirm

Bundles (Saved Configs)

packx -b api                         # Load .pack/bundles/api

Common Workflows

Default: Feature Context

# Most common - search for feature, copy to clipboard
packx --limit 49k -s "auth" -i "*.ts" -c

PR Review Context

packx --limit 49k --diff -c
packx --limit 49k --staged -f markdown --stdout > pr.md

Debug Context

packx --limit 49k --follow-imports src/problem.ts -c
packx --limit 49k -r src/problem.ts -c    # Include tests

Minimal Context (Max Efficiency)

packx --limit 49k --strip-comments --minify -i "*.ts" -c src/

Specific Files

# List specific files directly
packx --limit 49k src/auth.ts src/user.ts src/api.ts -c

Best Practices

  1. ALWAYS use --limit 49k - No exceptions unless user specifies
  2. Use -c for clipboard - Most common output method
  3. Preview first - --preview to check file selection
  4. Strip noise - --strip-comments --minify when token-tight
  5. Be specific - Use -s search and -i globs to narrow scope
  6. Check git state - --diff and --staged for PR context

Troubleshooting

Problem Solution
Too many tokens Add -i "*.ts", -x "test", or --strip-comments
Missing files Check globs, use --preview
Over 49k needed Split with -M 49k -o output (creates numbered files)
WriteFile hook error Use --stdout > file.md instead of --output file.md