spec-writer

spec-writer is a skill for Claude Code, Codex from kambleakash0/agent-skills. It costs 35 tokens per session (1,469 once invoked), scanned A, original, MIT.

A product-requirements-document writer that turns a clarified idea, conversation, and project repository context into a structured specification.

In plain words
What is it for?
Use it to write a PRD, feature specification, or requirements document for a new product, feature, change, or system.
Why use it?
It gathers the problem, intended users, reasons, requirements, and constraints in one document before implementation begins.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to write a PRD, feature specification, or requirements document for a new product, feature, change, or system.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/kambleakash0/agent-skills/spec-writer
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.

Any agent
npx skills add kambleakash0/agent-skills --skill spec-writer
Clone the repo
git clone --depth 1 https://github.com/kambleakash0/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for spec-writer

README.md
[![agentmods](https://agentmods.dev/badge/skills/kambleakash0/agent-skills/spec-writer/github.svg)](https://agentmods.dev/skills/kambleakash0/agent-skills/spec-writer)
Your own site
<a href="https://agentmods.dev/skills/kambleakash0/agent-skills/spec-writer"><img src="https://agentmods.dev/badge/skills/kambleakash0/agent-skills/spec-writer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for spec-writer

Your own site · 80×15
<a href="https://agentmods.dev/skills/kambleakash0/agent-skills/spec-writer"><img src="https://agentmods.dev/badge/skills/kambleakash0/agent-skills/spec-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,469 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00035 $0.01469
Opus 5 $0.00017 $0.00734
Sonnet 5 $0.00007 $0.00294
Haiku 4.5 $0.00003 $0.00147

Measured 10d ago against content hash 620eba2d2a09, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

spec-writer 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 10d 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.

skills/spec-writer/SKILL.md · 141 lines

How it starts

The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write a Product Requirements Document

This skill turns a clarified idea into a structured PRD using conversation and repository context. It assumes that major ambiguities have already been grilled out (for example with /grill-me), but it can also perform its own lightweight clarification when needed.

When to Use

Use this skill when the user:

  • Asks to "write a PRD", "product spec", "requirements doc", "feature specification", or similar.
  • Wants to document a new feature, change, or system in a structured way before implementation.
  • Has already clarified the idea and now needs a single, coherent document you can file as an issue, share with stakeholders, or feed into /slice-the-spec.

If the idea is still fuzzy or underspecified, recommend using /grill-me first and then come back to this skill.

Overall Workflow

You may skip or compress steps that are clearly already complete (for example, if the user pastes a detailed problem statement or user story list).

  1. Collect a rich problem description

    • Ask the user for a long, detailed description of:
      • The problem they want to solve
      • Who it is for
      • Why it matters now
      • Any initial solution ideas or constraints they already have
    • Encourage them to paste existing context (docs, tickets, research) instead of re‑typing everything.
  2. Explore the repo and verify assumptions

    • Inspect the codebase to understand current behavior, relevant modules, data models, and existing APIs.
    • Cross‑check the user’s assertions: note where the repo agrees, disagrees, or is silent, and adjust your understanding accordingly.
    • Capture any repo‑grounded facts that will matter for scope, edge cases, or implementation constraints.
  3. Consider alternative approaches

    • Ask the user whether they have considered other solution options or design directions.
    • Briefly outline 2–3 plausible approaches, with trade‑offs (complexity, time‑to‑ship, risk, UX impact).
    • Confirm which approach you should treat as the primary one for this PRD.

Read the full file on GitHub · 141 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. 10d ago First seen · 141 lines · 35 tokens per session scan A 620eba2d2a09

Subscribe to this mod's changes

spec-writer is a skill published in the GitHub repository kambleakash0/agent-skills (9 stars, last pushed yesterday), licensed MIT. It adds 35 tokens to every session and 1,469 once invoked, about $0.0002 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 2026-08-31.