verifier

verifier is an agent for Claude Code from swingerman/engineer. It costs 69 tokens per session (271 once invoked), scanned A, original, MIT.

A read-only checking agent that independently examines a feature another agent implemented. It runs architecture and code-quality checks, records evidence, and writes a handoff report without changing the project.

In plain words
What is it for?
Use it after implementation to check whether a feature follows the project's architecture and to report violations, evidence, and code-quality results for the next stage.
Why use it?
A fresh reviewer can find problems that the original implementer may overlook. It keeps checking separate from fixing, so reported issues remain visible for a human or another agent to decide.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter; names the NotebookEdit tool.

Part of the atdd plugin — 26 skills, 4 commands, 8 agents, 2 hooks, 1 plugin shipped together

Good fit Use it after implementation to check whether a feature follows the project's architecture and to report violations, evidence, and code-quality results for the next stage.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/swingerman/engineer/verifier
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/swingerman/engineer

Made for: Claude Code.

Or install atdd, the plugin that ships this one along with the rest of its 26 skills, 4 commands, 8 agents, 2 hooks, 1 plugin.

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 verifier

README.md
[![agentmods](https://agentmods.dev/badge/agents/swingerman/engineer/verifier/github.svg)](https://agentmods.dev/agents/swingerman/engineer/verifier)
Your own site
<a href="https://agentmods.dev/agents/swingerman/engineer/verifier"><img src="https://agentmods.dev/badge/agents/swingerman/engineer/verifier/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 verifier

Your own site · 80×15
<a href="https://agentmods.dev/agents/swingerman/engineer/verifier"><img src="https://agentmods.dev/badge/agents/swingerman/engineer/verifier.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 69 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 271 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 $0.00069 $0.00271
Opus 5.5 $0.00028 $0.00108
Sonnet 5.5 $0.00014 $0.00054
Haiku 4.5 $0.00007 $0.00027

Measured 23d ago against content hash 32ef963cece4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

verifier 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 23d 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.

engineer/agents/verifier.md · 26 lines

What it actually says

You are the fresh agent charter §6 calls for. You did not implement this feature, so don't defend it.

Run /engineer.arch-check for the feature in the brief. arch-check also runs crap-analyzer and records its summary as crap_results. Follow that skill's steps exactly, including its Step 0 gate.

Rules:

  • Don't modify code, tests or specs. Report violations; fixing them is a human/agent decision made after you.
  • The only file you write is the CP7 handoff that arch-check asks for.
  • Report tool output as evidence. Never write "looks fine".

Reply under ~1,500 tokens: the exit-criteria verdict, violation counts by kind, max CRAP with the top offenders, and the handoff's path. The detail lives in the handoff.

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. 23d ago First seen · 26 lines · 69 tokens per session scan A 32ef963cece4

Subscribe to this mod's changes

verifier is an agent published in the GitHub repository swingerman/engineer (157 stars, last pushed 24d ago), licensed MIT. It adds 69 tokens to every session and 271 once invoked, about $0.0003 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 2026-09-24.