verify

verify is a skill for Claude Code from sequenzia/agent-alchemy. It costs 63 tokens per session (1,115 once invoked), scanned A, original, MIT.

A checker for competitive-programming and LeetCode solutions that examines correctness, edge cases, and performance using code analysis, generated tests, and execution.

In plain words
What is it for?
Use it when reviewing an algorithm solution and you have both the problem statement and the solution code available.
Why use it?
It helps find wrong answers, missed boundary cases, and solutions that are too slow before you submit or rely on them.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: names the AskUserQuestion tool.

Part of the agent-alchemy-cs-tools plugin — 8 skills, 2 agents shipped together

Good fit Use it when reviewing an algorithm solution and you have both the problem statement and the solution code available.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sequenzia/agent-alchemy/verify
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 sequenzia/agent-alchemy --skill verify
Clone the repo
git clone --depth 1 https://github.com/sequenzia/agent-alchemy

Made for: Claude Code.

Or install agent-alchemy-cs-tools, the plugin that ships this one along with the rest of its 8 skills, 2 agents.

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 verify

README.md
[![agentmods](https://agentmods.dev/badge/skills/sequenzia/agent-alchemy/verify/github.svg)](https://agentmods.dev/skills/sequenzia/agent-alchemy/verify)
Your own site
<a href="https://agentmods.dev/skills/sequenzia/agent-alchemy/verify"><img src="https://agentmods.dev/badge/skills/sequenzia/agent-alchemy/verify/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 verify

Your own site · 80×15
<a href="https://agentmods.dev/skills/sequenzia/agent-alchemy/verify"><img src="https://agentmods.dev/badge/skills/sequenzia/agent-alchemy/verify.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,115 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 $0.00063 $0.01115
Opus 5.5 $0.00025 $0.00446
Sonnet 5.5 $0.00013 $0.00223
Haiku 4.5 $0.00006 $0.00112

Measured 1mo ago against content hash 9219cb193a7f, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

verify 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 1mo 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.

claude/cs-tools/skills/verify/SKILL.md · 137 lines

How it starts

The opening of the file, as written. The whole thing — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Solution Verifier

Verify competitive programming and LeetCode solutions for correctness through static analysis, automated test case generation, and execution.

CRITICAL: Complete ALL 4 phases. Do not stop after static analysis.

Phase 1: Parse Input

Goal: Extract the problem statement and solution code.

Parse $ARGUMENTS to extract:

  1. Problem statement — the full problem description with constraints, I/O format, and examples
  2. Solution code — the user's Python solution (inline code, file path, or pasted)

If both are in $ARGUMENTS, separate them. The problem statement typically comes first, followed by the solution code in a code block or after a separator.

If the solution is a file path, read it:

Read [file_path]

If the problem statement is missing, ask for it:

AskUserQuestion:
  question: "Please provide the problem statement for verification. I need it to generate test cases and validate correctness."
  options:
    - label: "Paste problem text"
      description: "Paste the full problem statement with constraints and examples"
    - label: "Describe the problem"
      description: "Describe what the problem asks — I'll generate test cases from that"

If the solution code is missing, ask for it:

AskUserQuestion:
  question: "Please provide your solution code to verify."
  options:
    - label: "Paste code"
      description: "Paste your Python solution code"
    - label: "Provide file path"
      description: "Give the path to your solution file"

If the solution is not Python, note this to the user and proceed with analysis (the verifier agent will handle language adaptation).

Phase 2: Spawn Verifier Agent

Goal: Delegate verification to the specialized agent.

Use the Task tool to spawn the solution-verifier agent:

Task:
  subagent_type: "agent-alchemy-cs-tools:solution-verifier"
  prompt: |
    ## Problem Statement
    [full problem text with all constraints, I/O format, and examples]

    ## Solution Code
    ```python
    [the user's solution code]
    ```

    Perform full verification following your structured process:
    1. Static analysis for logic errors and edge case handling
    2. Generate test cases (basic, edge, stress)
    3. Write and execute test harness
    4. Compile report with verdict

Read the full file on GitHub · 137 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. 1mo ago First seen · 137 lines · 63 tokens per session scan A 9219cb193a7f

Subscribe to this mod's changes

verify is a skill published in the GitHub repository sequenzia/agent-alchemy (45 stars, last pushed 4mo ago), licensed MIT. It adds 63 tokens to every session and 1,115 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 2026-08-30.

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