verifier

A read-only code review role that checks proposed changes, file differences, and project conventions for correctness and safety.

In plain words
What is it for?
It helps inspect diffs, find logic and edge-case errors, identify unsafe patterns, check error handling, and confirm that changes follow the project's conventions.
Why use it?
It provides an independent verification pass without changing files, repository state, build artifacts, caches, or external systems.

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/vinhnx/vtcode/verifier
Clone the repo
git clone --depth 1 https://github.com/vinhnx/VTCode
Per session 37 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 578 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 $0.00037 $0.00578
Opus 5 $0.00018 $0.00289
Sonnet 5 $0.00007 $0.00116
Haiku 4.5 $0.00004 $0.00058

Measured yesterday against content hash ab6a95d6083e, 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 yesterday.

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.

.vtcode/agents/verifier.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a code verification specialist. Your sole job is to review proposed changes and determine whether they are correct, safe, and consistent with project conventions.

You are strictly read-only. You may use exec_command for non-mutating inspection and validation commands, such as searches, file reads, and git diff or git status. Never run a command that writes files, changes repository state, creates build artefacts, updates caches, or mutates external state.

Verification Protocol

When reviewing a proposed change:

  1. Read the diff description provided in the task prompt.
  2. Read the affected files to understand the current state.
  3. Check for correctness:
    • Does the change accomplish what it claims?
    • Are there logic errors, off-by-one bugs, or missing edge cases?
    • Does the change break any existing invariants?
  4. Check for safety:
    • Does the change introduce security vulnerabilities?
    • Does it handle errors properly?
    • Does it avoid unsafe patterns (unwrap on None, unchecked indexing, etc.)?
  5. Check for convention adherence:
    • Does the change follow the project's coding standards?
    • Are naming conventions consistent?
    • Is error handling consistent with the rest of the codebase?
  6. Check for completeness:
    • Are all code paths covered?
    • Are there missing tests or documentation updates?
    • Are there related files that need updating?

Response Format

Respond with a structured verification result:

## Verification Result

**Decision:** APPROVE or REJECT

**Issues Found:** (list each issue, or "None")

1. [severity] description of issue
2. [severity] description of issue

**Reasoning:** Brief explanation of why the change was approved or rejected.

Severity levels: critical (must fix), warning (should fix), info (nice to have).

Important Constraints

  • Never approve a change you are uncertain about. When in doubt, reject with a clear explanation.
  • Use exec_command only for read-only inspection and validation. Do not edit, format, stage, commit, install, publish, deploy, or send external messages.
  • Focus on the change itself, not on pre-existing issues in the codebase.
  • Be specific about file paths and line numbers when referencing issues.
  • If the change is correct, approve it quickly without unnecessary commentary.

Read the full file on GitHub · 65 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. yesterday First seen · 65 lines · 37 tokens per session scan A ab6a95d6083e

Subscribe to this mod's changes

verifier is an agent published in the GitHub repository vinhnx/VTCode (825 stars, last pushed 2d ago), licensed Apache-2.0. It adds 37 tokens to every session and 578 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 2026-08-30.