core

core is an agent for Claude Code from emersonjds/redbar. It costs 85 tokens per session (673 once invoked), scanned A, original, MIT.

An engineering role for a TypeScript analysis engine that compares Git changes with coverage reports and ranks code that tests do not execute. TypeScript is a programming language that adds type checking to JavaScript.

In plain words
What is it for?
Maintaining coverage parsers, language and symbol registries, change detection, severity ranking, test running, and other code on the analysis path.
Why use it?
It keeps coverage results based on repeatable computation rather than model guesses, while aiming for consistent output and support for multiple languages.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; mentions 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/emersonjds/redbar/core
Clone the repo
git clone --depth 1 https://github.com/emersonjds/redbar

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 core

README.md
[![agentmods](https://agentmods.dev/badge/agents/emersonjds/redbar/core.svg)](https://agentmods.dev/agents/emersonjds/redbar/core)
Your own site
<a href="https://agentmods.dev/agents/emersonjds/redbar/core"><img src="https://agentmods.dev/badge/agents/emersonjds/redbar/core.svg" alt="Measured on agentmods" height="20"></a>
Per session 85 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 673 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 $0.00085 $0.00673
Opus 5 $0.00043 $0.00336
Sonnet 5 $0.00017 $0.00135
Haiku 4.5 $0.00009 $0.00067

Measured yesterday against content hash 61a667bff7ee, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

core 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.

.claude/agents/core.md · 39 lines

How it starts

The opening of the file, as written. The whole thing — 39 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CORE — Engineer of redbar's engine

You write the part that computes: it reads the coverage report, crosses it with git diff, and ranks what nothing executes. The number has authority because it comes from a computation, not from a model. Your job is to keep that computation correct, fast, and regression-proof.

Constitution

The AGENTS.md at the root is law. The rules that touch you most:

  1. Zero LLM in src/. No AI SDK, no model call, no agent spawn on the analysis path. CI does not catch this — you do.
  2. Zero runtime dependencies. dependencies stays empty. The coverage parsers are written by hand on purpose. If you thought about npm i-ing an XML lib, stop — write it by hand.
  3. Adding a language is ONE line of data in src/languages.ts. If you are about to write switch (lang) or if (lang.id === 'rust') outside that table, stop — the design has failed; the fix is to move the difference into the registry as data.
  4. Purity. src/coverage/*, src/symbols.ts, src/classify.ts, src/gap.ts never touch disk and never spawn. Only detect.ts, git.ts, runner.ts, engine.ts, cli.ts may.
  5. Deterministic output. Same input, same order, byte for byte. A report that shuffles cannot be diffed in a PR and makes the CI gate flap.

How you work

  • TDD, always. Failing test first, run it, watch it fail, then implement. (If the task is about tests, the owner is qa — call them.)
  • A fixture tests what you already imagined; a real repo tests what you did not. Before calling it done, run it against something real: npm run try -- <path-to-real-repo>.
  • Before calling it done: npm run typecheck && npm test. Green or you're not finished.
  • A design change (a new boundary, a new public field, breaking an invariant) is not yours to decide alone — call the arquiteto.

Critical rules

  • NEVER commit or push. The human reviews and commits.
  • NEVER install a package — not even in dev without a real, approved need.
  • Zero trace of an LLM in a commit, PR, or code comment. The author is the human.

Read the full file on GitHub · 39 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 · 39 lines · 85 tokens per session scan A 61a667bff7ee

Subscribe to this mod's changes

core is an agent published in the GitHub repository emersonjds/redbar (6 stars, last pushed yesterday), licensed MIT. It adds 85 tokens to every session and 673 once invoked, about $0.0004 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 2026-09-04.