ralph-prd

A feature-planning guide that creates a Product Requirements Document (PRD), a written description of what to build and how it should behave.

In plain words
What is it for?
Use it to plan a new feature or project, examine the existing codebase, ask clarifying questions, and outline an implementation approach.
Why use it?
It helps uncover missing decisions and edge cases before implementation, reducing assumptions and rework.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/wiggumdev/ralph/ralph-prd
Any agent
npx skills add wiggumdev/ralph --skill ralph-prd
Clone the repo
git clone --depth 1 https://github.com/wiggumdev/ralph

Made for: Claude Code, Codex.

Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,218 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00074 $0.02218
Opus 5 $0.00037 $0.01109
Sonnet 5 $0.00015 $0.00444
Haiku 4.5 $0.00007 $0.00222

Measured 2d ago against content hash 37bae0ad9bd5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ralph-prd scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

packages/claude/skills/ralph-prd/SKILL.md · 237 lines

How it starts

The opening of the file, as written. The whole thing — 237 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are helping a developer implement a new feature. Follow a systematic approach: understand the codebase deeply, identify and ask about all under-specified details, design elegant architectures, then implement.

Core Principles

  • Ask clarifying questions: Identify all ambiguities, edge cases, and under-specified behaviors. Ask specific, concrete questions rather than making assumptions. Wait for user answers before proceeding with implementation. Ask questions early (after understanding the codebase, before designing architecture).
  • Understand before acting: Read and comprehend existing code patterns first
  • Read files identified by agents: When launching agents, ask them to return lists of the most important files to read. After agents complete, read those files to build detailed context before proceeding.
  • Simple and elegant: Prioritize readable, maintainable, architecturally sound code
  • Use TodoWrite: Track all progress throughout

Phase 1: Discovery

Goal: Understand what needs to be built

Initial request: $ARGUMENTS

Actions:

  1. Create todo list with all phases
  2. If feature unclear, ask user for:
    • What problem are they solving?
    • What should the feature do?
    • Any constraints or requirements?
  3. Summarize understanding and confirm with user

Phase 2: Codebase Exploration

Goal: Understand relevant existing code and patterns at both high and low levels

Actions:

  1. Launch 2-3 code-explorer agents in parallel. Each agent should:

    • Trace through the code comprehensively and focus on getting a comprehensive understanding of abstractions, architecture and flow of control
    • Target a different aspect of the codebase (eg. similar features, high level understanding, architectural understanding, user experience, etc)
    • Include a list of 5-10 key files to read

    Example agent prompts:

    • "Find features similar to [feature] and trace through their implementation comprehensively"
    • "Map the architecture and abstractions for [feature area], tracing through the code comprehensively"
    • "Analyze the current implementation of [existing feature/area], tracing through the code comprehensively"
    • "Identify UI patterns, testing approaches, or extension points relevant to [feature]"

Read the full file on GitHub · 237 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 237 lines · 74 tokens per session scan A 37bae0ad9bd5

Subscribe to this mod's changes

ralph-prd is a skill published in the GitHub repository wiggumdev/ralph (19 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 74 tokens to every session and 2,218 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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