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 skills add tang-vu/social-posting-skills --skill post-substackgit clone --depth 1 https://github.com/tang-vu/social-posting-skillsWrote 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/skills/tang-vu/social-posting-skills/post-substack)<a href="https://agentmods.dev/skills/tang-vu/social-posting-skills/post-substack"><img src="https://agentmods.dev/badge/skills/tang-vu/social-posting-skills/post-substack/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/tang-vu/social-posting-skills/post-substack"><img src="https://agentmods.dev/badge/skills/tang-vu/social-posting-skills/post-substack.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00019 | $0.00362 |
| Opus 5.5 | $0.00008 | $0.00145 |
| Sonnet 5.5 | $0.00004 | $0.00072 |
| Haiku 4.5 | $0.00002 | $0.00036 |
Grade A, and why
post-substack 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 1mo 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.
What it actually says
Substack Adapter
Facts live in platforms/substack.json. A Substack publish emails actual
subscribers — that makes approval discipline non-optional.
What Substack rewards (culture)
- A consistent personal voice and recognizable sections — subscribers signed up for YOU.
- Email-subject-line quality titles; the subject is the open rate.
- Delivered value per issue: takeaways, not announcements.
Drafting from the content graph
core-claim→ subject-line title (clear > clever).context→ the lede paragraph.proof/technical→ the issue body, sectioned.demo/link→ inline links and a "try it" block.cta→ the close: what you'd like readers to do/reply.- Campaign items that are pure announcements should be reshaped into an issue with a point — or shipped as a Substack Note instead.
Publishing
manual→ draft package (title, subtitle, body, media manifest).agent-browser→ playbook exists for the publish editor; remember: "Publish" SENDS EMAIL. Stop at preview/schedule unless the human explicitly confirmed send.- No public write API.
Genuine engagement
- Reply to subscriber replies; newsletters are relationships.
- Cross-promote honestly; list-broking and fake testimonials are out.
Pitfalls
- Publishing emails subscribers — an accidental send is not recoverable. Agent-browser runs end at preview unless explicitly told to send.
- Blast-radius judgment: one good issue > three thin ones.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 1mo ago Changed · -75 lines · +6 tokens per session 97e5053c0d3e
- 1mo ago First seen · 121 lines · 13 tokens per session scan A d6e23e8eb237
post-substack is a skill published in the GitHub repository tang-vu/social-posting-skills (12 stars, last pushed 22d ago), licensed MIT. It adds 19 tokens to every session and 362 once invoked, about $0.0001 per session on Opus 5.5. 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.
Other skills, from other repositories
auto-research
Research uncertain questions with an explicit, user-approved web search or ChatGPT consultation, then present options and wait for implementation approval.
e2e-automator
Build robust end-to-end test suites with Playwright or Cypress. Covers page objects, fixtures, visual testing, and CI integration.
agentic-actions-auditor
Audits GitHub Actions workflows for security vulnerabilities in AI agent integrations including Claude Code Action, Gemini CLI, OpenAI Codex, and GitHub AI Inference. Detects attack vectors where attacker-controlled input reaches AI agents running in CI/CD pipelines.
anti-slop-design
Autonomous Principal Design Technologist. Cures vibe-coded software from AI frontend slop using curated token archetypes and 7-axis quality gating.
ad-campaign-analyzer
Analyze cross-channel campaign data, quantify uncertainty, and propose evidence-labeled budget tests without overstating causality.
apk-redteam-pipeline
End-to-end Android APK red-team pipeline.