write-spec

write-spec is a skill for Claude Code from smixs/disruptor-skills. It costs 35 tokens per session (5,171 once invoked), scanned A, original, MIT.

A prompt template that turns an agreed product design into a detailed implementation specification. The specification covers data, APIs, security, tests, deployment, and other build requirements.

In plain words
What is it for?
Use it after the design is settled to prepare instructions that developers or coding agents can use to build the product.
Why use it?
It records every required behavior and exposes missing decisions before implementation begins.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter.

Part of the disruptor plugin — 12 skills shipped together

Good fit Use it after the design is settled to prepare instructions that developers or coding agents can use to build the product.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/smixs/disruptor-skills/write-spec
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 smixs/disruptor-skills --skill write-spec
Clone the repo
git clone --depth 1 https://github.com/smixs/disruptor-skills

Made for: Claude Code.

Or install disruptor, the plugin that ships this one along with the rest of its 12 skills.

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 write-spec

README.md
[![agentmods](https://agentmods.dev/badge/skills/smixs/disruptor-skills/write-spec/github.svg)](https://agentmods.dev/skills/smixs/disruptor-skills/write-spec)
Your own site
<a href="https://agentmods.dev/skills/smixs/disruptor-skills/write-spec"><img src="https://agentmods.dev/badge/skills/smixs/disruptor-skills/write-spec/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 write-spec

Your own site · 80×15
<a href="https://agentmods.dev/skills/smixs/disruptor-skills/write-spec"><img src="https://agentmods.dev/badge/skills/smixs/disruptor-skills/write-spec.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 5,171 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 $0.05171
Opus 5 $0.00017 $0.02586
Sonnet 5 $0.00007 $0.01034
Haiku 4.5 $0.00003 $0.00517

Measured 9d ago against content hash 4f55d67a4d86, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

write-spec 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 9d 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/write-spec/SKILL.md · 865 lines

How it starts

The opening of the file, as written. The whole thing — 865 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write spec

Stage contract

  • Stage: 2. Spec · Kind: prompt
  • Inputs: the 7w3 design (stage 1) + known stack/constraints.
  • Outputs: a canonical, build-ready specification — every behavior stated; anything unspecified must not be silently invented at build time.
  • Entry gate: the design is settled (7w3's done-gate met).
  • Done when: DB, backend, UI, integrations, tests, and security can all be built from it without verbal clarification.
  • Next: the architecture-guardrails skill.
  • Maintains: uses CONTEXT.md vocabulary; surface new decisions as ADRs.
  • Note: this file is a prompt template — everything below the line is the prompt. Fill its <placeholders> with the design's facts and hand the whole thing to a fresh executor agent; don't paraphrase it.

You act as the product's chief architect, systems analyst, and technical lead. Your task is to prepare not an overview and not a marketing description, but a canonical implementation specification from which the team and AI agents can build the product without constant verbal clarifications.

Write the specification in the language the user works in (<language> placeholder, default: the language of the input design), in plain understandable language, but with sufficient technical precision. If you use a technical term, explain it immediately in simple words. Do not write generic phrases like "security needs to be thought through". Instead, pin down concrete rules, tables, states, constraints, checks, and readiness criteria.

Input Data

Product: <product name>

Short description: <what the product does and for whom>

Target audience: <who the users, customers, administrators, external participants are>

Specification language: <language; default: the language of the input design>

Current implementation stage: <e.g.: Phase 1 / MVP / first production release / pilot>

What is definitely in scope for the current stage:

  • <item>
  • <item>
  • <item>

Read the full file on GitHub · 865 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. 9d ago First seen · 865 lines · 35 tokens per session scan A 4f55d67a4d86

Subscribe to this mod's changes

write-spec is a skill published in the GitHub repository smixs/disruptor-skills (18 stars, last pushed 2mo ago), licensed MIT. It adds 35 tokens to every session and 5,171 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 2026-08-30.

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