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/peters/horizon/agents-mdgit clone --depth 1 https://github.com/peters/horizonWrote 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/peters/horizon/agents-md)<a href="https://agentmods.dev/instructions/peters/horizon/agents-md"><img src="https://agentmods.dev/badge/instructions/peters/horizon/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 | $0.07634 | $0.07634 |
| Opus 5 | $0.03817 | $0.03817 |
| Sonnet 5 | $0.01527 | $0.01527 |
| Haiku 4.5 | $0.00763 | $0.00763 |
Grade B, and why
horizon AGENTS.md scanned grade B with 1 finding 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 today.
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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
- Debian/Ubuntu: `sudo apt install -y build-essential pkg-config libxkbcommon-dev libwayland-dev libxcb-render0-dev libxcb-shape0-dev libxcb-xfixes0-dev libvulkan-dev libgl-dev cmake` How it starts
The opening of the file, as written. The whole thing — 364 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Horizon — Agent Guidelines
Source of truth for all contributors and AI agents working on this project.
Quick Start
An AI agent given these instructions should be able to go from zero to a running Horizon binary.
Repository: https://github.com/peters/horizon.git
Option A — Download a release binary (fastest)
Pre-built binaries are attached to GitHub releases. Prefer the latest non-prerelease tag. Use gh release download --repo peters/horizon or download from https://github.com/peters/horizon/releases/latest.
| Platform | Asset | Contents |
|---|---|---|
| Linux x64 | horizon-linux-x64.tar.gz |
Single horizon binary — extract and make executable |
| macOS x64 | horizon-osx-x64.tar.gz |
Single horizon binary — extract and make executable |
| Windows x64 | horizon-windows-x64.exe |
Ready-to-run executable |
No Rust toolchain or system headers are needed for this path.
Option B — Build from source
Prerequisites
- Rust stable ≥ 1.95 (edition 2024). Install via rustup if not present.
- Linux only: the eframe/wgpu rendering stack needs system headers. Install them before
cargo build:- Debian/Ubuntu:
sudo apt install -y build-essential pkg-config libxkbcommon-dev libwayland-dev libxcb-render0-dev libxcb-shape0-dev libxcb-xfixes0-dev libvulkan-dev libgl-dev cmake - Fedora:
sudo dnf install -y gcc pkg-config wayland-devel libxkbcommon-devel vulkan-loader-devel mesa-libGL-devel cmake - Arch:
sudo pacman -S --needed base-devel wayland libxkbcommon vulkan-icd-loader cmake
- Debian/Ubuntu:
- macOS: Xcode Command Line Tools (
xcode-select --install). Metal ships with the OS. - Windows: MSVC build tools (installed automatically by
rustupon themsvctarget). DX12/Vulkan drivers ship with the GPU driver. - Speech input (
--features speech, opt-in): additionally needs CMake and a C++ compiler (to build the vendored transcribe.cpp), plus on Linux the ALSA headers (libasound2-dev/alsa-lib-devel) for microphone capture. The default build does not require these.
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.
- today Changed · +20 tokens per session 7b9bc86c4b65
- 4d ago First seen · 364 lines · 7,614 tokens per session scan B 588732bab465
horizon AGENTS.md is an instructions file published in the GitHub repository peters/horizon (699 stars, last pushed today), licensed MIT. It adds 7,634 tokens to every session, about $0.0382 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
squeez CLAUDE.md
Claude Code instructions for claudioemmanuel/squeez, covering claude.md, commands, hard constraints, architecture and key files.
Monoloth AGENTS.md
Instructions for noahain/Monoloth, covering agents.md, stack, layout, build / test commands and from repo root.
plannotator AGENTS.md
AGENTS.md instructions for backnotprop/plannotator, covering plannotator, project structure, server runtimes, installation and environment variables.
intelligent-terminal rust.instructions.md
Concise Rust coding conventions for this repository.
agentgateway copilot-instructions.md
Copilot instructions for agentgateway/agentgateway: Do not check for, speculate about, or report compilation errors during code review. Compilation diagnostics from review are frequently incorrect; rely on CI to detect and report compilation failures.
mq commit.instructions.md
Instructions for harehare/mq: Use the following format for commit messages.