first-principles-marketplace

First Principles — Product Management Plugin

Agent-native product management toolkit for Claude Code. Takes a raw product idea and delivers a scoped MVP, PRD, and execution plan — all grounded in first-principles thinking.

How It Works

"I want to build a webhook integration that syncs Mercury to QuickBooks"

        Orchestrator (product-workflow)
        │
        ├─ Phase 1: Parallel Analysis
        │  ├── Challenge Requirements  (subagent)
        │  └── Assess Constraints      (subagent)
        │
        ├─ Phase 2: Synthesize MVP Scope
        │  └── Merge signals → in/out decisions
        │       ↓
        │  [User confirms MVP scope]
        │
        ├─ Phase 3: Parallel Specification
        │  ├── Write PRD         (subagent)
        │  └── Plan Execution    (subagent)
        │
        └─ Output: PRD + Execution Plan

Trigger

The plugin exposes a single skill: first-principles:product-workflow.

It triggers when you say things like:

• "I want to build..."
• "Help me plan..."
• "Analyze requirements for..."
• "Scope an MVP for..."
• "Write a PRD for..."
• "Break down this project..."

Or invoke it directly:

/first-principles:product-workflow

Build a webhook integration that syncs Mercury Bank transactions to QuickBooks

What It Does

The skill runs a 4-phase pipeline with parallel subagents:

Phase	What happens	Method
0. Parse	Extract idea, context, requirements	Orchestrator
1. Analyze	Challenge every requirement + assess constraints	2 parallel subagents
2. Scope	Merge signals into MVP scope (3-5 items max)	Orchestrator, then user confirms
3. Specify	Write PRD + plan execution tasks	2 parallel subagents
4. Deliver	Consolidated output	Orchestrator

Design Principles

• Parallel by default — Independent workers run simultaneously via Task tool
• Structured I/O — Every worker outputs YAML, not prose
• First-principles thinking — Ruthlessly question every requirement, bias toward deletion
• Single entry point — One skill triggers the entire pipeline

Installation

From GitHub

/plugin marketplace add <owner>/first-principles-skills
/plugin install first-principles@first-principles-marketplace

Local Development

claude --plugin-dir /path/to/first-principles-skills

License

MIT