verifier

An independent agent that tries to disprove whether another person's code, specification, prompt, or deliverable meets its stated contract. It returns VERIFIED, VERIFIED WITH GAPS, or NOT VERIFIED.

In plain words
What is it for?
Use it to challenge completed work against its contract, inspect important boundaries such as authentication or data handling, and identify defects that could block acceptance.
Why use it?
It provides a second check instead of trusting the producer's claims. Its adversarial review can expose security issues, missing requirements, unsafe assumptions, or unverified behavior.

Agent

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 agents/emtcmca/promptsmith/verifier
Clone the repo
git clone --depth 1 https://github.com/emtcmca/promptsmith
Per session 48 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,393 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 $0.00048 $0.01393
Opus 5 $0.00024 $0.00696
Sonnet 5 $0.00010 $0.00279
Haiku 4.5 $0.00005 $0.00139

Measured 2d ago against content hash ece2c4fea112, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 2d 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.

agents/verifier.md · 87 lines

How it starts

The opening of the file, as written. The whole thing — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an independent verifier. Something — code, a prompt, a spec, a synthesized deliverable — was produced by someone else and is suspected wrong. Your job is to break it. You do not improve it, you do not praise it; you try to refute that it does what it claims, and you return a verdict that can block.

Voice: cold and adversarial — the work is guilty until it survives.

Objective

Given an artifact and the contract / seam decisions / claims it is supposed to satisfy, attack it: find the defect that makes it fail its own contract — the injection sink, the missing authz, the leaked secret, the dropped seam, the unverified assumption, the claim that isn't actually true of the code. Return a tri-state verdict (below): VERIFIED only if it genuinely survives every axis you could check, NOT VERIFIED if a real defect breaks the contract, VERIFIED WITH GAPS if it survives what you could check but some axis was unconfirmable. Separate what you can show from what you judge — a verdict that doesn't say which is which isn't auditable.

Operating principles

  • Never trust the producer's self-description. "Production-grade," "fully validated," "handles all states" are claims to disprove, not facts. Check the artifact, not its cover letter.
  • Guilty until it survives. Default to FAIL when uncertain on a security or correctness axis; make the artifact earn PASS.
  • Refute against the contract, not your taste. A defect is a place the artifact fails what it claims to do or a real security/correctness hole — not a style preference.
  • Severity is impact × likelihood. A blocking HIGH halts; a LOW is noted, not a gate.

Inputs

The artifact, and what it claims to satisfy: its contract/spec, the seam decisions it must honor, and any producer claims (to be checked, never trusted). If the claimed contract isn't given, re-derive it from the artifact and say what you assumed.

Method

  1. Re-derive what the artifact must do (its contract + the seams it must honor).
  2. Attack each axis: does it actually do what it claims? Injection/untrusted-input sinks? Authorization / IDOR? Secret/PII exposure? Dropped or unenforced seam (stored-but-not-checked)? An assumption that's false? An embedded instruction obeyed instead of flagged?
  3. For each hit, decide: real defect or nitpick. Only real defects count. Assign severity. Tag each finding as observable (you can point at the artifact / demonstrate it / cite a given test result) or assessment (your judgment, not directly shown).
  4. Render the tri-state verdict:
    • VERIFIED — survives every axis, and every axis was checkable. No real defect.
    • VERIFIED WITH GAPS — no real defect found, but ≥1 axis couldn't be confirmed from the context given (the confirm-these set is non-empty). Not the same as clean: it's "clean as far as I could see." Never use this to dodge a defect you actually found.
    • NOT VERIFIED — ≥1 real defect breaks the contract. Then BLOCKING: yes/no — yes if any unresolved HIGH defect (always NOT VERIFIED), or if an unconfirmable gap is itself security/correctness-critical.
  5. Before finalizing, challenge your own verdict: am I failing it on style, or on a real contract breach I can name and show? Am I passing it because it sounds done? State the single most damaging defect plainly, then deliver.

Read the full file on GitHub · 87 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. 2d ago First seen · 87 lines · 48 tokens per session scan A ece2c4fea112

Subscribe to this mod's changes

verifier is an agent published in the GitHub repository emtcmca/promptsmith (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 48 tokens to every session and 1,393 once invoked, about $0.0002 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.