prospec-design

prospec-design is a skill for Claude Code, Codex from benwu95/prospec. It costs 80 tokens per session (2,637 once invoked), scanned A, original, MIT.

A design-specification assistant for creating or extracting interface and interaction details. It works with Pencil, Figma, Penpot, or HTML designs.

In plain words
What is it for?
Use it to produce visual and interaction specifications from a proposal, or to recover those specifications from an existing design tool.
Why use it?
It helps turn a written proposal or an existing design into documented guidance that developers can follow.

Skill for Claude CodeCodex

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 skills/benwu95/prospec/prospec-design
Any agent
npx skills add benwu95/prospec --skill prospec-design
Clone the repo
git clone --depth 1 https://github.com/benwu95/prospec

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 prospec-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/benwu95/prospec/prospec-design.svg)](https://agentmods.dev/skills/benwu95/prospec/prospec-design)
Your own site
<a href="https://agentmods.dev/skills/benwu95/prospec/prospec-design"><img src="https://agentmods.dev/badge/skills/benwu95/prospec/prospec-design.svg" alt="Measured on agentmods" height="20"></a>
Per session 80 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,637 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 $0.00080 $0.02637
Opus 5 $0.00040 $0.01319
Sonnet 5 $0.00016 $0.00527
Haiku 4.5 $0.00008 $0.00264

Measured today against content hash 323674f9c4c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prospec-design 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 today.

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.

.agents/skills/prospec-design/SKILL.md · 204 lines

How it starts

The opening of the file, as written. The whole thing — 204 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prospec Design Skill

Activation

When triggered, briefly describe:

  • That you'll read proposal.md and determine the design workflow mode
  • Generate Mode: produce design-spec.md + interaction-spec.md from proposal
  • Extract Mode: reverse-extract specs from an existing design tool via MCP
  • Platform adapter will guide tool-specific operations

Language Policy

Write each generated document in the language the Constitution's Language Policy rule assigns to its path — change artifacts and their archived summaries in the project's artifact language, the trust zone (Knowledge base, Feature Specs, index) in English. One skill run may write both. Keep code, identifiers, technical terms, and git commit messages in English.

CLI Prerequisite (required)

The prospec CLI is a required file for this skill — its deterministic steps call prospec commands. Probe BEFORE any other step; there is no manual fallback.

  1. Run prospec --version (Bash).
  2. Command not found / not executable → STOP. Ask the user to install the prospec standalone executable — the one-click installer script from the project README (macOS/Linux install.sh, Windows install.ps1) or a release binary from GitHub Releases; prospec is NOT published to npm. Then re-run this skill.
  3. Version older than 2.1.0 → STOP. Report the installed vs required version and ask the user to upgrade, then re-run this skill.

Hand-executing a CLI-owned mutation is NEVER the fallback — that re-introduces the nondeterministic serialization this contract exists to remove.

Startup Loading

  1. [STABLE] MANDATORY — Read references/design-spec-format.md for design-spec.md format
  2. [STABLE] MANDATORY — Read references/interaction-spec-format.md for interaction-spec.md format
  3. [DYNAMIC] Read .prospec/changes/[name]/proposal.md — parse UI Scope and User Stories
  4. [DYNAMIC] Read .prospec.yaml — check design.platform setting (pencil|figma|penpot|html)
  5. [DYNAMIC] Load the platform adapter reference based on design.platform:

Read the full file on GitHub · 204 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. today Changed 323674f9c4c6
  2. 4d ago First seen · 204 lines · 80 tokens per session scan A ab7d4fb64bfb

Subscribe to this mod's changes

prospec-design is a skill published in the GitHub repository benwu95/prospec (5 stars, last pushed yesterday), licensed MIT. It adds 80 tokens to every session and 2,637 once invoked, about $0.0004 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.