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-xgit 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-x)<a href="https://agentmods.dev/skills/tang-vu/social-posting-skills/post-x"><img src="https://agentmods.dev/badge/skills/tang-vu/social-posting-skills/post-x/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-x"><img src="https://agentmods.dev/badge/skills/tang-vu/social-posting-skills/post-x.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 | $0.00013 | $0.02150 |
| Opus 5 | $0.00006 | $0.01075 |
| Sonnet 5 | $0.00003 | $0.00430 |
| Haiku 4.5 | $0.00001 | $0.00215 |
Grade A, and why
post-x 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 12d 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 — 229 lines — stays where its author put it; the contents beside it link to each section on GitHub.
X (Twitter) Posting Skill
Platform Overview
X (formerly Twitter) is the real-time social platform for tech, media, and breaking news. 500M+ monthly active users. Excellent for building a personal brand, networking with industry leaders, and driving traffic. Threads (multi-tweet posts) are powerful for in-depth content.
Platform Constraints
- Character Limit: 280 characters per tweet (free), 25,000 (Premium)
- Media: Up to 4 images, 1 video, or 1 GIF per tweet
- Hashtags: 1-2 max (more reduces engagement); banned in promoted posts (Jun 2025)
- Links: Shortened via t.co, show as preview cards
- Threads: Chain of tweets for longer content
- Polls: Up to 4 options, 24h-7d duration
- Verification: X Premium ($8/month), account must be 90 days old
Link Placement Strategy
DEFAULT: Put links in a REPLY to your own tweet, not in the main tweet.
- Tweets with external links get significantly less reach in the algorithm (estimated 30-50% reduction)
- t.co link shortening eats into your 280 character limit
- Best strategy: Post a compelling text-only tweet, then immediately reply with the link
- Exception: If the link generates a rich card preview that adds value, it can go in the main tweet
- For threads: Put the link in the last tweet of the thread
Rate Limits
X enforces strict rate limits. Exceeding them triggers a "Rate Limit Exceeded" error (resolves in 15min to 24h).
| Action | Limit |
|---|---|
| Posts per day | 2,400 (tweets + retweets + replies) |
| Posts per 30 minutes | 50 |
| DMs per day | 500 |
| New follows per day | 400 |
| Post views (verified) | 10,000/day |
| Post views (unverified) | 1,000/day |
| Post views (new unverified) | 500/day |
Automation Rules
Allowed:
- Scheduling tweets and threads for future publication
- Auto-posting content from RSS feeds or trusted sources
- Analytics and monitoring tools
- Non-spammy welcome DMs to new followers
Banned (will result in account penalties):
- Mass following or unfollowing accounts
- Bulk liking or retweeting to inflate engagement
- Sending unsolicited or spammy DMs
- Posting identical content across multiple accounts
- Automated replies to keywords
- Using fake engagement bots (buying likes/retweets/followers)
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.
- 12d ago First seen · 229 lines · 13 tokens per session scan A 2232c260833c
post-x is a skill published in the GitHub repository tang-vu/social-posting-skills (9 stars, last pushed 6mo ago), licensed MIT. It adds 13 tokens to every session and 2,150 once invoked, about $0.0001 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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