proof-of-work

proof-of-work is a skill for Claude Code, Codex from darkroomengineering/cc-settings. It costs 50 tokens per session (1,057 once invoked), scanned A, original, MIT.

A machine-checking step that runs a project's type checks, tests, and code-style checks, plus a screenshot check for user-interface work. It reports whether the changes are ready for human review.

In plain words
What is it for?
Verifying an agent's code changes, running the available checks in a project, and confirming that interface changes include a screenshot.
Why use it?
It catches common problems before someone spends time reviewing a change, so reviewers can focus on design and behavior rather than basic failures.

Skill for Claude CodeCodex

Written for Claude Code and Codex: shipped in a Claude Code plugin, but also reads $CODEX_HOME. Also seen: mentions Codex.

Part of the darkroom plugin — 24 skills, 11 agents, 4 hooks shipped together

Good fit Verifying an agent's code changes, running the available checks in a project, and confirming that interface changes include a screenshot.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/darkroomengineering/cc-settings/proof-of-work
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 darkroomengineering/cc-settings --skill proof-of-work
Clone the repo
git clone --depth 1 https://github.com/darkroomengineering/cc-settings

Made for: Claude Code, Codex.

Or install darkroom, the plugin that ships this one along with the rest of its 24 skills, 11 agents, 4 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 proof-of-work

README.md
[![agentmods](https://agentmods.dev/badge/skills/darkroomengineering/cc-settings/proof-of-work/github.svg)](https://agentmods.dev/skills/darkroomengineering/cc-settings/proof-of-work)
Your own site
<a href="https://agentmods.dev/skills/darkroomengineering/cc-settings/proof-of-work"><img src="https://agentmods.dev/badge/skills/darkroomengineering/cc-settings/proof-of-work/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 proof-of-work

Your own site · 80×15
<a href="https://agentmods.dev/skills/darkroomengineering/cc-settings/proof-of-work"><img src="https://agentmods.dev/badge/skills/darkroomengineering/cc-settings/proof-of-work.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,057 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00050 $0.01057
Opus 5.5 $0.00020 $0.00423
Sonnet 5.5 $0.00010 $0.00211
Haiku 4.5 $0.00005 $0.00106

Measured 9d ago against content hash 46456dcb2ebf, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

proof-of-work 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/proof-of-work/SKILL.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Proof of Work

The Amdahl-shrink move from the Orchestration Tax: human review is the serial bottleneck, so don't spend it confirming what a machine can verify. An agent's diff is review-ready only when the machine-verifiable battery is green — types, tests, lint (and a screenshot for UI). What a machine can prove shouldn't cost a human's attention.

The gate

Run the battery on the current working tree:

PROOF_RUNNER="${CODEX_HOME:-$HOME/.codex}/darkroom/source/src/scripts/proof.ts"
[ -f "$PROOF_RUNNER" ] || PROOF_RUNNER="$HOME/.claude/src/scripts/proof.ts"
bun "$PROOF_RUNNER"

This is the portable installed runner — it works in any repo. (bun run proof is a shortcut that only exists inside the cc-settings repo itself; don't reach for it in a consumer project.) It detects typecheck / test / lint from the project's package.json, runs them cheapest-first, and prints one verdict:

  • exit 0 → review-ready ✓
  • exit 1 → NOT review-ready ✗ — fix the failing gate before a human looks

Projects can opt into advisory probes by depending on the tool — the gate then runs the project's pinned binary: react-doctor (React render/quality score, telemetry off) and/or deslop (framework-agnostic cross-file dead-code count). Advisory results are reported but never flip the verdict — deterministic signals alongside the hard gates, not blockers. Silent for projects that don't depend on them.

For UI changes, attach a screenshot (via the chrome-devtools MCP) as the visual half of the proof — tests can't prove "looks right".

Standalone Codex semantic probe

Use spawn_agent to create a fresh read-only reviewer, send_message to deliver context while it runs, followup_task to trigger another turn once it is idle, wait_agent to wait, and interrupt_agent only to stop its current turn. Treat findings as advisory beside the mechanical verdict. Never spawn codex-verifier and never run codex-run.ts from inside Codex. Skip the Claude bridge branch below.

Read the full file on GitHub · 66 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 Changed 46456dcb2ebf
  2. 13d ago Changed 4aee7e0119e1
  3. 21d ago Changed 560b06d09171
  4. 1mo ago Changed · -6 tokens per session 95ea7dcff710
  5. 2mo ago First seen · 66 lines · 56 tokens per session scan A bd3ce976b274

Subscribe to this mod's changes

proof-of-work is a skill published in the GitHub repository darkroomengineering/cc-settings (52 stars, last pushed yesterday), licensed MIT. It adds 50 tokens to every session and 1,057 once invoked, about $0.0002 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 2026-08-30.

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