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 skills/eastsun5566/hackmd-skills/hackmdnpx skills add EastSun5566/hackmd-skills --skill hackmdgit clone --depth 1 https://github.com/EastSun5566/hackmd-skillsWhat 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 | $0.00051 | $0.02856 |
| Opus 5 | $0.00026 | $0.01428 |
| Sonnet 5 | $0.00010 | $0.00571 |
| Haiku 4.5 | $0.00005 | $0.00286 |
Grade A, and why
hackmd-markdown 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 2d 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 — 563 lines — stays where its author put it; the contents beside it link to each section on GitHub.
HackMD Flavored Markdown Skill
This skill enables AI agents to create and edit HackMD documents with full support for HackMD Flavored Markdown, diagrams, and external embeds.
Metadata (Title and Tags)
HackMD metadata is managed through the editor UI, not in the document content.
Title:
- Edit using the title field in the HackMD editor
- If not set, the first H1 header (
# Heading) will be used as the title - If no title or H1 exists, the note will be titled "Untitled"
Tags:
- Edit using the tags field in the HackMD editor
Other Settings:
- Configure in the note's "Settings" menu
- Slide mode settings are in the "Slide mode" section of the "Share" menu
Tags (Inline Format)
Define tags inline at the start of document:
###### tags: `feature` `documentation` `v2.0`
[!NOTE] Tags can also be managed through the HackMD editor UI.
Table of Contents
Auto-generate ToC with:
[TOC]
This will be replaced with a hierarchical list of headers.
Alert Boxes
Create colored alert boxes with:
:::success
Success message with :tada: emoji!
:::
:::info
Information message with :mega: emoji!
:::
:::warning
Warning message with :zap: emoji!
:::
:::danger
Danger message with :fire: emoji!
:::
:::spoiler Click to reveal
Hidden content here :stuck_out_tongue_winking_eye:
:::
:::spoiler {state="open"} Expanded by default
This spoiler is open initially
:::
Enhanced Blockquotes
Add author, time, and color to blockquotes:
> This is a quote with metadata
> [name=John Doe] [time=2024-01-15 10:30] [color=#3b5998]
> Nested quotes also work
> [name=Jane Smith] [time=2024-01-15 10:35] [color=red]
> > Even deeper nesting!
> > [name=Bob] [time=2024-01-15 10:36] [color=#00ff00]
Code Blocks with Line Numbers
// Line numbers start from 1
var s = "JavaScript";
alert(s);
# Line numbers start from 101
def greet(name):
print(f"Hello, {name}!")
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.
- 2d ago First seen · 563 lines · 51 tokens per session scan A a39f05d8eb3d
hackmd-markdown is a skill published in the GitHub repository EastSun5566/hackmd-skills (2 stars, last pushed 2mo ago), licensed MIT. It adds 51 tokens to every session and 2,856 once invoked, about $0.0003 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.
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