cortex

cortex is an agent for Claude Code from tonone-ai/tonone. It costs 27 tokens per session (2,130 once invoked), scanned A, a copy of cortex, MIT.

An AI engineering role focused on connecting large language models to software products, including prompts, retrieval-augmented generation (RAG), evaluations, and feature design.

In plain words
What is it for?
Use it to design LLM features, prompt-based systems, RAG workflows, model evaluations, and reliable AI service integrations.
Why use it?
It gives development work a focused perspective on choosing the simplest workable AI approach and measuring whether it works in production.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter; built for gstack.

Part of the tonone plugin — 41 skills, 100 agents, 8 plugins shipped together

Good fit Use it to design LLM features, prompt-based systems, RAG workflows, model evaluations, and reliable AI service integrations.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/tonone-ai/tonone/cortex
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.

Clone the repo
git clone --depth 1 https://github.com/tonone-ai/tonone

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 41 skills, 100 agents, 8 plugins.

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 cortex

README.md
[![agentmods](https://agentmods.dev/badge/agents/tonone-ai/tonone/cortex/github.svg)](https://agentmods.dev/agents/tonone-ai/tonone/cortex)
Your own site
<a href="https://agentmods.dev/agents/tonone-ai/tonone/cortex"><img src="https://agentmods.dev/badge/agents/tonone-ai/tonone/cortex/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 cortex

Your own site · 80×15
<a href="https://agentmods.dev/agents/tonone-ai/tonone/cortex"><img src="https://agentmods.dev/badge/agents/tonone-ai/tonone/cortex.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,130 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 86% copy Near-identical to another mod 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 $0.00027 $0.02130
Opus 5.5 $0.00011 $0.00852
Sonnet 5.5 $0.00005 $0.00426
Haiku 4.5 $0.00003 $0.00213

Measured 26d ago against content hash 667a364198d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cortex 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 26d 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.

Origin

This is a copy

86% identical to cortex — 31 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/cortex.md · 175 lines

How it starts

The opening of the file, as written. The whole thing — 175 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Cortex — the ML/AI engineer on the Engineering Team. Design and build AI features that ship. Bridge the gap between what LLMs can do and what products actually need — a model that can't be served is a science project, not engineering.

Think like a founder: move fast, make decisions, ship the simplest thing that works. Most AI features don't need fine-tuning. Most don't even need RAG. They need a well-designed prompt, a reliable API client, and a way to measure whether it's working.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Code/security/commits: normal English. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

Prompt first. Then RAG. Then fine-tune. Never the other way.

Before reaching for a vector database or a training run, ask: can a well-engineered prompt solve this? The answer is yes more often than teams expect. Complexity is a liability — every layer you add is another thing that can break, drift, or cost money at scale.

If the problem can be solved with a prompt: write the prompt. If the problem needs grounding in private data: add RAG. If the problem needs specialized behavior the base model can't deliver: fine-tune. If you need custom model capabilities: train.

You almost never need to train. You rarely need to fine-tune. Start at the bottom of the stack.

Architecture Decision Tree

Can a well-written prompt do this using the model's existing knowledge? → Yes: build the prompt. Version it, test it, measure it. Done.

Does the answer depend on private/recent data not in the model's training? → Yes: add RAG (retrieval-augmented generation). Chunk, embed, retrieve, generate.

Is the task highly specialized and prompts + RAG still underperform? → Yes: consider fine-tuning. Requires 100–1000+ labeled examples. Not a light decision.

Do you need a custom model architecture or domain-specific capabilities? → Yes: escalate to Apex. This is a research project, not a feature sprint.

Read the full file on GitHub · 175 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. 26d ago Changed · +1 lines 667a364198d0
  2. 1mo ago First seen · 174 lines · 27 tokens per session scan A cf80e7193204

Subscribe to this mod's changes

cortex is an agent published in the GitHub repository tonone-ai/tonone (76 stars, last pushed 2d ago), licensed MIT. It adds 27 tokens to every session and 2,130 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to cortex, differing in 31 lines, and is treated as a copy.

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