to-spec

to-spec is a skill for Claude Code from lttr/claude-marketplace. It costs 30 tokens per session (884 once invoked), scanned A, original, MIT.

A skill that turns the current conversation and codebase understanding into a written feature specification, also called a product requirements document.

In plain words
What is it for?
Use it to create a spec from existing context after examining the repository, its terminology, architecture decisions, dependencies, and code structure.
Why use it?
It records the feature’s requirements, testing boundaries, technical decisions, and relevant project conventions before implementation begins.

Skill for Claude Code

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

Part of the aiwork plugin — 11 skills, 2 hooks shipped together

Good fit Use it to create a spec from existing context after examining the repository, its terminology, architecture decisions, dependencies, and code structure.

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

Made for: Claude Code.

Or install aiwork, the plugin that ships this one along with the rest of its 11 skills, 2 hooks.

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 to-spec

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/lttr/claude-marketplace/to-spec"><img src="https://agentmods.dev/badge/skills/lttr/claude-marketplace/to-spec.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 884 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 $0.00030 $0.00884
Opus 5 $0.00015 $0.00442
Sonnet 5 $0.00006 $0.00177
Haiku 4.5 $0.00003 $0.00088

Measured 3d ago against content hash fe2a5ca4c66e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

to-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 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.

plugins/aiwork/skills/to-spec/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

This skill takes the current conversation context and codebase understanding and produces a spec (you may know this document as a PRD). Do NOT interview the user, just synthesize what you already know.

Process

  1. If the task folder has an intent.md, read it first. The spec answers it in the originator's terms. Where the intent conflicts with an ADR, the glossary, or the codebase, raise it with the user and record what stays unresolved under Open Concerns. Don't edit the intent.

  2. Explore the repo to understand the current state of the codebase, if you haven't already. Use the project's domain glossary vocabulary throughout the spec, and respect any ADRs in the area you're touching.

  3. Sketch out the seams at which you're going to test the feature. Existing seams should be preferred to new ones. Use the highest seam possible. If new seams are needed, propose them at the highest point you can. The fewer seams across the codebase, the better - the ideal number is one.

Check with the user that these seams match their expectations.

  1. Audit the technical decisions the feature depends on: what handles each solved problem (auth, validation, jobs, …), where the code lives, what schema/API contracts change. Decisions already settled in the conversation go into the spec as-is. For any that were never settled, check the project's existing dependencies and stack conventions — usually those already cover it and no new dependency is needed; record what will be used. Only when nothing in the project covers a genuinely solved problem, pick the idiomatic candidate for the stack and confirm it with the user alongside the seams. Either way, don't leave the choice implicit in the spec.

  2. Write the spec using the template below, then save it per the aiwork-protocol skill.

Problem Statement

The problem that the user is facing, from the user's perspective.

Solution

The solution to the problem, from the user's perspective.

User Stories

A LONG, numbered list of user stories. Each user story should be in the format of:

Read the full file on GitHub · 85 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. 3d ago Changed · +8 lines fe2a5ca4c66e
  2. 11d ago First seen · 77 lines · 30 tokens per session scan A 4fbb606c757b

Subscribe to this mod's changes

to-spec is a skill published in the GitHub repository lttr/claude-marketplace (2 stars, last pushed yesterday), licensed MIT. It adds 30 tokens to every session and 884 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.

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