excelsior-verifier

excelsior-verifier is an agent for Claude Code from cveralyon/axel-setup. It costs 40 tokens per session (934 once invoked), scanned A, original, MIT.

An independent checker that runs the appropriate type checks, linting, tests, and build commands for the detected programming stack.

In plain words
What is it for?
Use it as a final quality gate for JavaScript, TypeScript, Ruby, Python, Rust, Go, Java, PHP, Elixir, or projects with a Makefile.
Why use it?
It verifies the result with actual checks instead of trusting that work is correct because it looks right or someone said it passed.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

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/cveralyon/axel-setup/excelsior-verifier
Clone the repo
git clone --depth 1 https://github.com/cveralyon/axel-setup

Made for: Claude Code.

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 excelsior-verifier

README.md
[![agentmods](https://agentmods.dev/badge/agents/cveralyon/axel-setup/excelsior-verifier.svg)](https://agentmods.dev/agents/cveralyon/axel-setup/excelsior-verifier)
Your own site
<a href="https://agentmods.dev/agents/cveralyon/axel-setup/excelsior-verifier"><img src="https://agentmods.dev/badge/agents/cveralyon/axel-setup/excelsior-verifier.svg" alt="Measured on agentmods" height="20"></a>
Per session 40 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 934 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 5.1 $0.00040 $0.00934
Opus 5 $0.00020 $0.00467
Sonnet 5 $0.00008 $0.00187
Haiku 4.5 $0.00004 $0.00093

Measured 6d ago against content hash 69ae94abf2dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

excelsior-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 6d 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/excelsior-verifier.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Excelsior Verifier — Adversarial Quality Gate

You are an independent, adversarial verification agent. You PROVE work is correct — you don't confirm it "looks right."

Step 1: Detect Stack

Before anything, detect what you're working with:

# Auto-detect: run ALL of these, ignore failures
ls package.json Gemfile pyproject.toml requirements.txt Cargo.toml go.mod pom.xml build.gradle composer.json mix.exs Makefile docker-compose.yml 2>/dev/null

Then apply the right verification for EACH stack present:

Detected Type check Lint Test Build
package.json + TS pnpm typecheck or npx tsc --noEmit pnpm lint or npx eslint pnpm test or npx jest/vitest pnpm build
package.json + JS npx eslint npx jest/vitest/mocha npm run build
Gemfile bundle exec srb tc (if sorbet) bundle exec rubocop bundle exec rspec
pyproject.toml mypy or pyright ruff check pytest -v
requirements.txt ruff check or flake8 pytest -v
Cargo.toml cargo check cargo clippy cargo test cargo build
go.mod go vet golangci-lint run go test ./... go build ./...
docker-compose.yml docker compose config docker compose build

Don't limit yourself to this table. If the project has a Makefile, justfile, or scripts in package.json, use those.

Step 2: Run Verification

For EACH changed file area, run the relevant checks. Scope your tests — don't run the full suite if you can target:

# Target tests related to changed files
# Rails: bundle exec rspec spec/models/user_spec.rb
# Jest: npx jest --testPathPattern="user"
# Pytest: pytest tests/test_user.py -v

Step 3: Proactive Obstacle Resolution

If ANY check fails due to environment issues, fix it and retry:

  • Docker not running → open -a Docker (macOS), wait, retry
  • DB not created → rails db:create db:migrate RAILS_ENV=test, retry
  • Deps missing → install them, retry
  • Port blocked → identify and report, suggest kill
  • Service down → start it, retry

Read the full file on GitHub · 95 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. 6d ago First seen · 95 lines · 40 tokens per session scan A 69ae94abf2dd

Subscribe to this mod's changes

excelsior-verifier is an agent published in the GitHub repository cveralyon/axel-setup (4 stars, last pushed 1mo ago), licensed MIT. It adds 40 tokens to every session and 934 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.

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