product-spec-builder

A guided command that turns a product idea into a Product-Spec.md file, a written description of what the product should do. It can also update an existing specification through a structured interview.

In plain words
What is it for?
Use it to gather requirements, clarify a new product concept, challenge assumptions, distill what someone wants, or revise an existing product specification.
Why use it?
It helps uncover missing requirements and unclear decisions before development begins. Different interview styles suit quick ideas, deep exploration, stress testing, or later revisions.

Command for Claude Code

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 commands/zxpmail/reqforge/product-spec-builder
Clone the repo
git clone --depth 1 https://github.com/zxpmail/ReqForge

Made for: Claude Code.

Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 392 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 $0.00012 $0.00392
Opus 5 $0.00006 $0.00196
Sonnet 5 $0.00002 $0.00078
Haiku 4.5 $0.00001 $0.00039

Measured 3d ago against content hash 8504064bc920, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

product-spec-builder 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 3d 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.

adapters/claude-code/.claude/skills/product-spec-builder/commands/product-spec-builder.md · 32 lines

What it actually says

Command: /product-spec-builder

Entry: /product-spec-builder or describe product idea. Full workflow → SKILL.md.

Mode routing (read one workflow ref)

Mode Trigger Read
Quick one sentence / "quick" / "fast" references/workflow-quick-mode.md only
Distillation distill / 蒸馏 / infer what I need references/distillation-mode.md
Light Grill grill me / 烤问 / stress-test references/light-grill-mode.md
0-to-1 no Spec yet, full deep-dive references/workflow-0-to-1.md
Iteration Product-Spec.md exists references/workflow-iteration.md

Startup routing → references/startup-check.md.

Phases (index)

Phase Reference Acceptance
Discovery workflow-0-to-1 One-paragraph concept agreed
Detail / Interview conversation-strategy Spec sections fillable without guessing
Distillation distillation-mode 4-path inference + cross-validation; Distillation Map (✅/⚠️/❓); ❓ feeds 0-to-1/Quick clarifying questions
Critique Gate critique-gate Three structural signals scanned; findings resolved or marked [TBD]
Spec write product-spec-template Product-Spec.md confirmed (HARD-GATE lifts only after explicit user confirm)
Iteration workflow-iteration Major/minor → edit Spec; moderate scoped feature → /change-manager propose
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. 3d ago First seen · 32 lines · 12 tokens per session scan A 8504064bc920

Subscribe to this mod's changes

product-spec-builder is a command published in the GitHub repository zxpmail/ReqForge (18 stars, last pushed 13d ago), licensed MIT. It adds 12 tokens to every session and 392 once invoked, about $0.0001 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.