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.
npx agentmods add instructions/bnd-1/horsemd/agents-mdgit clone --depth 1 https://github.com/BND-1/horseMDWrote 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/bnd-1/horsemd/agents-md)<a href="https://agentmods.dev/instructions/bnd-1/horsemd/agents-md"><img src="https://agentmods.dev/badge/instructions/bnd-1/horsemd/agents-md.svg" alt="Measured on agentmods" 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 | $0.04112 | $0.04112 |
| Opus 5 | $0.02056 | $0.02056 |
| Sonnet 5 | $0.00822 | $0.00822 |
| Haiku 4.5 | $0.00411 | $0.00411 |
Grade A, and why
horseMD 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 4d 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 — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository Guidelines
Project Structure & Module Organization
HorseMD is an Electron + Vite + React Markdown editor with a shared renderer for desktop and Capacitor mobile builds.
src/main/index.js: Electron main-process lifecycle, window, IPC assembly, menus, assets, and update checks.src/main/filesystem.js,watchers.js,documents.js: file operations, watchers, dialogs, and PDF export.src/preload/index.js: securewindow.apibridge exposed to the renderer.src/renderer/src/: React app, Milkdown editor, hooks, shell components, themes, i18n, platform shim.src/renderer/src/components/Editor.jsx: Crepe/ProseMirror editor wrapper; keep new editor features in focusededitor-*.jshelpers when possible.src/renderer/src/hooks/andsrc/renderer/src/lib/: file ops, lifecycle, outline, find/replace, menus, and review actions.docs/: architecture, features, development workflow, mobile notes, and manual testing.scripts/: lightweight verification and CDP helpers.website/: static product/download homepage;guide/: isolated VitePress user tutorial site.build/,icons/,android/,ios/: packaging assets and mobile shells.
Build, Test, and Development Commands
npm install
npm run dev
npm run build
npm start
npm run dist
npm run build:mobile
npm run test:source-map
npm run guide:check
node scripts/test-strike-guard.mjs
npm run dev: starts Electron/Vite hot reload.npm run build: builds main, preload, and renderer intoout/; CI uses this.npm start: runs the built app.npm run dist: creates the host-platform installer viaelectron-builder.npm run build:mobile: builds the Capacitor renderer intodist-mobile/.npm run test:source-map: runs Markdown raw-offset ↔ ProseMirror mapping tests for tables, duplicate text, code, images, lists, and HTML.npm run guide:check: validates tutorial metadata, versions, links, assets, screenshot privacy/dimensions, and builds the guide site.node scripts/test-strike-guard.mjs: runs CriticMarkup strike regression checks.
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.
- 4d ago First seen · 168 lines · 4,112 tokens per session scan A 0b5626196942
horseMD AGENTS.md is an instructions file published in the GitHub repository BND-1/horseMD (377 stars, last pushed 16d ago), licensed MIT. It adds 4,112 tokens to every session, about $0.0206 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 2026-08-30.
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).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
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.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.