HyMarkX AGENTS.md

HyMarkX AGENTS.md is an instructions file for Codex, OpenCode from NAME0x0/HyMarkX. It costs 795 tokens per session, scanned A, original, Apache-2.0.

A repository instruction file for HyMarkX, a project that adds its own document syntax while supporting CommonMark and GitHub Flavored Markdown. It lists rules to read before editing and requires verification after changes.

In plain words
What is it for?
Use it when changing the HyMarkX parser, command-line tools, language server, syntax, or tests.
Why use it?
It keeps syntax behavior, browser compatibility, source locations, package boundaries, and the conformance test suite from being broken accidentally.

Instructions file for CodexOpenCode

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 instructions/name0x0/hymarkx/agents-md
Clone the repo
git clone --depth 1 https://github.com/NAME0x0/HyMarkX

Made for: Codex, OpenCode.

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 HyMarkX AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/name0x0/hymarkx/agents-md.svg)](https://agentmods.dev/instructions/name0x0/hymarkx/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/name0x0/hymarkx/agents-md"><img src="https://agentmods.dev/badge/instructions/name0x0/hymarkx/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 795 This file is loaded in full into every session.
When invoked 795 The same file — it is already loaded in full.
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 $0.00795 $0.00795
Opus 5 $0.00398 $0.00398
Sonnet 5 $0.00159 $0.00159
Haiku 4.5 $0.00080 $0.00080

Measured 3d ago against content hash 27e8ba3c8f32, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

HyMarkX 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 3d 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.

AGENTS.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent instructions

For coding agents working in this repository: Codex, Claude Code, Cursor, Copilot, and anything else that reads a conventions file.

Read llms.txt first. It is the canonical description of the language and lists the mistakes that are actually common. Everything below is about working on the repository, not about writing .hmx documents.

Before changing anything

Read CLAUDE.md for the hard invariants. The ones that get violated most:

  1. A document with no HMX construct must render as CommonMark + GFM. The conformance suite (652 examples) is a CI gate and has never regressed across seven syntax additions. If your change moves that number, the change is wrong — do not adjust the suite.
  2. Only @hymarkx/parser may import micromark, mdast, hast, or unified. Enforced by scripts/check-boundaries.mjs, not by convention.
  3. Only @hymarkx/cli and @hymarkx/language-server may touch node: builtins. Everything else must run unchanged in a browser.
  4. Every AST node carries a real source span. Dropping spans is a bug, not a shortcut.
  5. Recoverable problems are Diagnostics with stable codes, never thrown exceptions.
  6. Syntax changes need an ADR and a SPEC.md update before code.

Verification is not optional

pnpm check            # build, lint, typecheck, test, boundary check
pnpm format:check

pnpm check runs pnpm build first, because several suites import workspace packages by name and resolve through dist/. A green local run without building proves nothing.

Do not report success on the basis that code compiles. Every task in this project that reported success while carrying a real defect did so by trusting a step it had not run — a failing typecheck, a hidden workaround, a conformance regression, a verification using a library that was not installed.

Where decisions live

Nothing important lives in commit messages or chat. If you are about to make a judgement call, it is probably already recorded:

Read the full file on GitHub · 70 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. 3d ago First seen · 70 lines · 795 tokens per session scan A 27e8ba3c8f32

Subscribe to this mod's changes

HyMarkX AGENTS.md is an instructions file published in the GitHub repository NAME0x0/HyMarkX (2 stars, last pushed 9d ago), licensed Apache-2.0. It adds 795 tokens to every session, about $0.0040 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 2026-08-31.