Borrowing it
Nothing to install: this file belongs to Heapy/kortex. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Heapy/kortex/main/AGENTS.mdgit clone --depth 1 https://github.com/Heapy/kortexWrote 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.
[](https://agentmods.dev/instructions/heapy/kortex/agents-md)<a href="https://agentmods.dev/instructions/heapy/kortex/agents-md"><img src="https://agentmods.dev/badge/instructions/heapy/kortex/agents-md/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.
<a href="https://agentmods.dev/instructions/heapy/kortex/agents-md"><img src="https://agentmods.dev/badge/instructions/heapy/kortex/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01306 | $0.01306 |
| Opus 5.5 | $0.00522 | $0.00522 |
| Sonnet 5.5 | $0.00261 | $0.00261 |
| Haiku 4.5 | $0.00131 | $0.00131 |
Grade A, and why
kortex AGENTS.md 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.
How it starts
The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.
kortex
One tree, three hosts. The same skills ship as Claude Code plugins, Codex plugins, and Junie extensions, so every change has to be made in each host's manifest, not just the one you are looking at.
Layout
| Path | What it is |
|---|---|
plugins/<plugin>/skills/<skill>/SKILL.md |
the skill itself: YAML frontmatter (name, description) then the body |
plugins/<plugin>/agents/<agent>.md |
a subagent: YAML frontmatter then the prompt; loaded by Claude Code and Junie |
plugins/<plugin>/plugin.json |
portable Agent Plugins manifest; no host reads it yet |
plugins/<plugin>/.claude-plugin/plugin.json |
Claude Code manifest |
plugins/<plugin>/.codex-plugin/plugin.json |
Codex manifest |
plugins/<plugin>/extension.json |
Junie manifest |
.claude-plugin/marketplace.json |
Claude Code marketplace index |
.junie-extension/marketplace.json |
Junie marketplace index |
scripts/sync-agents.main.kts |
regenerates the Codex copy of every agent |
docs/ |
field reports; not shipped with any plugin |
A skill's description is what the host matches a user request against — write it as the set of
phrases that should trigger it, not as a summary.
Specs
Two specifications govern the tree, and they split cleanly: one owns the skill, the other owns the directory around it.
| Spec | Owns | Where |
|---|---|---|
| Agent Skills | SKILL.md: frontmatter fields, name/description limits, scripts/, references/, assets/ |
https://agentskills.io/specification |
| Agent Plugins 1.0.0 | the plugin directory: plugin.json in the plugin root, skills discovered at skills/, MCP at mcp.json |
https://github.com/agentplugins/agent-plugins-spec, spec/1.0.0.md, plugin.schema.json |
Agent Plugins says nothing about SKILL.md — it delegates to Agent Skills. Constraints worth
keeping in mind while editing: name must match the skill's directory name and is limited to
lowercase alphanumerics and single hyphens; description is capped at 1024 characters; skills are
found one level under skills/ and nowhere deeper.
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.
- 1mo ago First seen · 91 lines · 1,306 tokens per session scan A 3975e7a21296
kortex AGENTS.md is an instructions file published in the GitHub repository Heapy/kortex (7 stars, last pushed 2d ago), licensed Apache-2.0. It adds 1,306 tokens to every session, about $0.0052 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).