dependency-research

Research

Research before building. Check if a battle-tested solution exists before writing custom utility code.

Iron Law

RESEARCH BEFORE BUILDING

Never write custom utility code without first checking if a battle-tested solution exists. The best code is code you don't write. A maintained package with thousands of users will always beat a hand-rolled utility in reliability, edge cases, and long-term maintenance.

When This Skill Activates

Triggers — creating or modifying code that:

• Parses, formats, or validates data (dates, URLs, emails, UUIDs, etc.)
• Implements common algorithms (sorting, diffing, hashing, encoding)
• Wraps HTTP clients, retries, rate limiting, caching
• Handles file system operations beyond basic read/write
• Implements CLI argument parsing, logging, or configuration
• Creates test utilities (mocking, fixtures, assertions)

Does NOT trigger for:

• Domain-specific business logic unique to this project
• Glue code connecting existing components
• Trivial operations (< 5 lines, single-use)
• Code that intentionally avoids external dependencies (e.g., zero-dep libraries)

Research Process

Phase 1: Need Analysis

Before searching, define what you actually need:

Need: {one-sentence description of the capability}
Constraints: {runtime, bundle size, license, zero-dep requirement}
Must-haves: {non-negotiable requirements}
Nice-to-haves: {optional features}

Phase 2: Search

Spawn an Explore subagent when you can spawn agents, to keep main session context clean; otherwise search directly, using the template's questions as your checklist.

Prompt template for the Explore agent:

Agent(subagent_type="Explore"):
"Research existing solutions for: {need description}

Search for:
1. npm/PyPI/crates packages that solve this (check package.json/requirements.txt for ecosystem)
2. Existing utilities in this codebase (grep for related function names)
3. Framework built-ins that already handle this

For each candidate, find:
- Package name and weekly downloads (if applicable)
- Last publish date and maintenance status
- Bundle size / dependency count
- API surface relevant to our need
- License compatibility

Return top 3 candidates with pros/cons, or confirm nothing suitable exists."