substack-note

substack-note is a skill for Claude Code, Codex from az9713/claude-cowork-content-plugin. It costs 36 tokens per session (516 once invoked), scanned A, original, MIT.

A writing aid that turns long-form material into short posts for Substack Notes, the social feed connected to Substack newsletters. It extracts insights, questions, tips, reflections, opinions, teasers, and resource suggestions.

In plain words
What is it for?
Use it to create conversational Substack Notes that share lessons, invite discussion, preview longer writing, or point readers to useful resources.
Why use it?
It removes the need to find several short discussion points inside one longer piece. It helps adapt the source for readers who may see only a brief post before deciding whether to read more.

Skill for Claude CodeCodex

Part of the content-repurposing plugin — 7 skills, 6 commands shipped together

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 skills/az9713/claude-cowork-content-plugin/substack-note
Any agent
npx skills add az9713/claude-cowork-content-plugin --skill substack-note
Clone the repo
git clone --depth 1 https://github.com/az9713/claude-cowork-content-plugin

Made for: Claude Code, Codex.

Or install content-repurposing, the plugin that ships this one along with the rest of its 7 skills, 6 commands.

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 substack-note

README.md
[![agentmods](https://agentmods.dev/badge/skills/az9713/claude-cowork-content-plugin/substack-note.svg)](https://agentmods.dev/skills/az9713/claude-cowork-content-plugin/substack-note)
Your own site
<a href="https://agentmods.dev/skills/az9713/claude-cowork-content-plugin/substack-note"><img src="https://agentmods.dev/badge/skills/az9713/claude-cowork-content-plugin/substack-note.svg" alt="Measured on agentmods" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 516 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00036 $0.00516
Opus 5 $0.00018 $0.00258
Sonnet 5 $0.00007 $0.00103
Haiku 4.5 $0.00004 $0.00052

Measured 3d ago against content hash 47dea7822d98, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

substack-note 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

content-repurposing/skills/substack-note/SKILL.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Substack Note Skill

You are a Substack content strategist who creates engaging Notes that build community, drive discussion, and funnel readers to longer content.

Process

Step 1: Analyze the Source

Read the source content and identify:

  • Key insights worth sharing as standalone thoughts
  • Behind-the-scenes moments or personal reflections
  • Questions that would spark discussion
  • Quick tips or tactical advice
  • Observations about trends or industry changes
  • Teasers for deeper content

Step 2: Generate Notes

Create 5-7 Substack Notes from the source. Each Note should be:

  • Length: 100-300 words (sweet spot for Notes engagement)
  • Tone: Conversational, like talking to a smart friend
  • Structure: Hook → Insight → Discussion prompt or CTA
Note Types to Include:
  1. The Quick Insight: One key lesson in 2-3 paragraphs
  2. The Question: Pose a thought-provoking question with context
  3. The Behind-the-Scenes: Share what didn't make it into the main content
  4. The Hot Take: A spicy opinion extracted from the content
  5. The Teaser: Preview of the longer content with a "read more" hook
  6. The Resource Share: Highlight a tool, framework, or resource from the content
  7. The Thread-Starter: Statement designed to generate comments and debate
For Each Note, Provide:
  • The full Note text, ready to post
  • A suggested posting time (Morning/Afternoon/Evening + day of week)
  • Expected engagement type (Likes, Comments, Restacks)
  • Whether it should link to longer content

Step 3: Save Output

Save all notes to a markdown file in the workspace folder. Name: substack-notes-[source-name].md Separate each note with a horizontal rule (---).

Quality Standards

  • Notes should feel authentic, not promotional
  • Each Note should stand completely on its own
  • Include at least 2 Notes that ask questions (drives comments)
  • At least 1 Note should be a teaser for longer content
  • Write in first person - Substack is personal
  • Avoid hashtags - Substack Notes don't use them

Read the full file on GitHub · 55 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 · 55 lines · 36 tokens per session scan A 47dea7822d98

Subscribe to this mod's changes

substack-note is a skill published in the GitHub repository az9713/claude-cowork-content-plugin (16 stars, last pushed 6mo ago), licensed MIT. It adds 36 tokens to every session and 516 once invoked, about $0.0002 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.

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