prototype-developer

prototype-developer is an agent for Claude Code from vedanta/the-system. It costs 26 tokens per session (9,430 once invoked), scanned A, original, LGPL-3.0.

A prototyping agent that creates interactive HTML demonstrations from wireframes and API analysis. It also prepares detailed materials for developers who will build the finished product.

In plain words
What is it for?
Use it to build reviewable HTML prototypes, test ideas with stakeholders, analyze API needs, and prepare development handoff documentation.
Why use it?
It lets stakeholders try and validate an interface idea before full implementation begins. The handoff package helps developers understand how to continue the work.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

Good fit Use it to build reviewable HTML prototypes, test ideas with stakeholders, analyze API needs, and prepare development handoff documentation.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/vedanta/the-system/prototype-developer
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.

Clone the repo
git clone --depth 1 https://github.com/vedanta/the-system

Made for: Claude Code.

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 prototype-developer

README.md
[![agentmods](https://agentmods.dev/badge/agents/vedanta/the-system/prototype-developer/github.svg)](https://agentmods.dev/agents/vedanta/the-system/prototype-developer)
Your own site
<a href="https://agentmods.dev/agents/vedanta/the-system/prototype-developer"><img src="https://agentmods.dev/badge/agents/vedanta/the-system/prototype-developer/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 prototype-developer

Your own site · 80×15
<a href="https://agentmods.dev/agents/vedanta/the-system/prototype-developer"><img src="https://agentmods.dev/badge/agents/vedanta/the-system/prototype-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 9,430 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 unknown 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 $0.00026 $0.09430
Opus 5.5 $0.00010 $0.03772
Sonnet 5.5 $0.00005 $0.01886
Haiku 4.5 $0.00003 $0.00943

Measured 1mo ago against content hash 1efcc6ee7415, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prototype-developer 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 1mo 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.

.claude/agents/prototype-developer.md · 1,365 lines

The source is not reproduced here

Licensed LGPL-3.0

The repository is licensed LGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 1mo ago First seen · 1,365 lines · 26 tokens per session scan A 1efcc6ee7415

Subscribe to this mod's changes

prototype-developer is an agent published in the GitHub repository vedanta/the-system (9 stars, last pushed 7mo ago), licensed LGPL-3.0. It adds 26 tokens to every session and 9,430 once invoked, about $0.0001 per session on Opus 5.5. 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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