# prd-to-spec

Turns a PRD into a technical SPEC covering architecture, APIs, data, errors, and implementation contracts. Use it before coding begins.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 500 installs · ★ 294
- Author: smallnest
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/smallnest/goal-workflow/tree/HEAD/skills/prd-to-spec/SKILL.md
- Updated: 2026-09-13
- HTML: https://affpapa.org/en/nevibecode/skills/prd-to-spec

## What it does

This skill turns a Product Requirements Document into a technical specification that an engineer or AI agent can implement against. The output covers system architecture, API design, data models, error handling, and implementation contracts. It fits the gap between agreed product requirements and a concrete build plan.

The workflow finds or receives the PRD, optionally inspects the codebase, asks focused technical questions, drafts the SPEC, collects feedback, and saves the final document. You can provide a file path, a GitHub Issue URL, pasted content, or let it scan `tasks/`. With no existing codebase, it proposes the architecture from scratch. A PRD must be available before the workflow can begin.

The resulting document can cover component boundaries, file changes, schema and migration plans, endpoints, validation, business logic, failure modes, security, and performance. Questions can address where logic belongs, how data is stored, API versioning, dependencies, and load constraints.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add smallnest/goal-workflow --skill prd-to-spec -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/prd-to-spec/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/prd-to-spec/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add smallnest/goal-workflow --skill prd-to-spec -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/prd-to-spec/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add smallnest/goal-workflow --skill prd-to-spec -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/prd-to-spec/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install smallnest/goal-workflow prd-to-spec
```

2. **Manually: put the files in place**
- File: `.github/skills/prd-to-spec/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add smallnest/goal-workflow --skill prd-to-spec -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/smallnest/goal-workflow --path skills/prd-to-spec
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/prd-to-spec/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add smallnest/goal-workflow --skill prd-to-spec -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/smallnest/goal-workflow/tree/HEAD/skills/prd-to-spec/SKILL.md

## When to use it
- turn a PRD into an implementation-ready SPEC
- map a feature into an existing architecture
- define API endpoints and data contracts
- plan schema changes and migrations
- surface technical ambiguities before coding

## Example prompts
- Turn `tasks/prd-priority-system.md` into a technical SPEC and save the final document.
- Inspect the current codebase, ask the key technical questions, and draft a SPEC for this PRD.
- Scan `tasks/`, show the available PRDs, then generate a specification after I choose one.

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 60366dfcdf4db81e.

BEGIN THIRD-PARTY FILE 60366dfcdf4db81e
````text
---
name: prd-to-spec
description: "Transform a PRD into a technical SPEC document — architecture, API design, data model, error handling, and implementation contracts. Triggers on: prd-to-spec, prd to spec, prd转spec, 需求转设计, 需求转规格, generate spec from prd, design from prd, 技术方案, 设计方案."
user-invocable: true
---

# prd-to-spec — PRD to Technical Specification

Transform a Product Requirements Document (PRD) into a detailed technical SPEC that an engineer or AI agent can implement against. The PRD says *what* to build; the SPEC says *how* to build it.

---

## When to Use

- A `/prd` has been generated and you need to bridge the gap to implementation
- You want architecture decisions documented before coding starts
- Multiple developers/agents will implement the feature and need a shared contract
- You need to validate technical feasibility before committing to a PRD
- You want to catch design issues early — before code is written

---

## The Job

1. **Locate PRD** — find or receive the PRD document
2. **Analyze context (optional)** — if a codebase exists, scan it to understand current architecture, patterns, and constraints
3. **Ask clarifying questions** — resolve technical ambiguities (max 3-5 questions)
4. **Generate SPEC** — produce a structured technical specification
5. **Review** — present to user for feedback and iteration
6. **Save** — write final SPEC to agreed location

---

## Step 1: Locate PRD

Find the input PRD in one of these ways:

```
Provide the PRD to convert:

A. File path (e.g., tasks/prd-priority-system.md)
B. GitHub Issue URL
C. Paste PRD content directly
D. Auto-detect: scan tasks/ directory for recent PRDs
```

If auto-detecting, list available PRDs and let the user choose:

```
Found PRDs in tasks/:
  1. tasks/prd-priority-system.md (2024-03-15)
  2. tasks/prd-user-auth.md (2024-03-10)

Which PRD should I convert? [1/2]
```

---

## Step 2: Analyze Context (Optional)

**Skip this step if no codebase exists yet** (greenfield project). In that case, the SPEC will propose architecture from scratch based on the PRD requirements and clarifying questions.

If a codebase exists, scan it to understand:

- **Existing architecture** — how the current system is structured
- **Tech stack** — languages, frameworks, libraries already in use
- **Patterns** — naming conventions, file organization, error handling approach
- **Database** — current schema, migration tool, ORM
- **API style** — REST/GraphQL/gRPC, authentication method, response format
- **Testing** — test framework, coverage patterns, test utilities

This ensures the SPEC aligns with the existing system rather than proposing incompatible solutions.

---

## Step 3: Clarifying Questions
````
END THIRD-PARTY FILE 60366dfcdf4db81e

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---
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