build-right-prototype

build-right-prototype is a skill for Codex from pax-k/build-right. It costs 53 tokens per session (766 once invoked), scanned A, original, MIT.

A disposable coding experiment that answers one specific logic or interface-design question with runnable evidence.

In plain words
What is it for?
Use it to test a state model, data shape, interaction, layout, or other design question in an isolated temporary workspace.
Why use it?
It helps resolve uncertainty before production work begins, without treating the experiment as finished product code or customer validation.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: $skill-name invocation.

Good fit Use it to test a state model, data shape, interaction, layout, or…

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Install with agentmods
npx agentmods add skills/pax-k/build-right/build-right-prototype
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 pax-k/build-right --skill build-right-prototype
Clone the repo
git clone --depth 1 https://github.com/pax-k/build-right

Made for: 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 build-right-prototype

README.md
[![agentmods](https://agentmods.dev/badge/skills/pax-k/build-right/build-right-prototype.svg)](https://agentmods.dev/skills/pax-k/build-right/build-right-prototype)
Your own site
<a href="https://agentmods.dev/skills/pax-k/build-right/build-right-prototype"><img src="https://agentmods.dev/badge/skills/pax-k/build-right/build-right-prototype.svg" alt="Measured on agentmods" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 766 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 $0.00053 $0.00766
Opus 5 $0.00026 $0.00383
Sonnet 5 $0.00011 $0.00153
Haiku 4.5 $0.00005 $0.00077

Measured 7d ago against content hash 75e2d0449d6a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

build-right-prototype 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 7d 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/build-right-prototype/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Build Right Prototype

Use this cross-cutting companion to answer one design question. A prototype is evidence, not product code, customer validation, or permission to implement.

Required Reading

  • Read references/logic.md for state, transition, data-shape, or behavioral contract questions.
  • Read references/ui.md for layout, hierarchy, or interaction questions.
  • Use assets/templates/prototype-evidence.md for the retained evidence packet.
  • Read the target repository's instructions, product authority, execution rules, and Git state before creating anything.

Workflow

  1. State exactly one prototype question and one observable success signal.
  2. Classify the mode as logic or ui; stop if the question mixes unresolved concerns that cannot be observed together.
  3. Inspect repository conventions and git status --short. Record unrelated work and do not touch it.
  4. Create the prototype in a disposable temporary directory or detached temporary worktree. Never edit the main worktree by default. If neither safe isolation option is possible, stop and ask.
  5. Make the prototype runnable with one documented Bun-native command such as bun run prototype or bun index.ts.
  6. Run syntax, type, or build smoke verification appropriate to the prototype, plus the smallest assertion that proves the question's success signal.
  7. Observe the result. Separate what was demonstrated from what remains assumed.
  8. Write docs/evidence/prototypes/<slug>.md in the target repository using the evidence template. This retained packet is the only default main worktree edit.
  9. Route any production implementation through $build-right-feature-planning. Never copy, move, or promote prototype code directly into production.

Safety Contract

  • Use fake, local, or read-only data. Never call a production mutation path.
  • Do not use live credentials unless the user explicitly authorizes a bounded, non-mutating proof and repository policy allows it.
  • Do not automatically commit, push, merge, publish, deploy, clean up, delete, or promote.
  • Do not automatically abort or resolve an existing Git operation.
  • Leave disposal or cleanup as an explicit user choice and report the temporary path or worktree.
  • Label the finding prototype-evidence when observed and prototype-assumption when it remains inferred.

Read the full file on GitHub · 80 lines

Files

What ships with it

4 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. 7d ago First seen · 80 lines · 53 tokens per session scan A 75e2d0449d6a

Subscribe to this mod's changes

build-right-prototype is a skill published in the GitHub repository pax-k/build-right (4 stars, last pushed 1mo ago), licensed MIT. It adds 53 tokens to every session and 766 once invoked, about $0.0003 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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