x-post-writer

x-post-writer is a skill for Claude Code, Codex from sergebulaev/x-skills. It costs 120 tokens per session (1,735 once invoked), scanned A, original, MIT.

A writing assistant for X, formerly called Twitter, that drafts one post or a short two- or three-post thread. It chooses a post structure based on the intended response, such as replies, reposts, likes, or bookmarks.

In plain words
What is it for?
Use it to turn a topic or rough sentence into a single post or short thread, choose an appropriate opening style, humanize the wording, and prepare it for publication.
Why use it?
A short post has limited space and must make its point quickly. The assistant helps shape the opening and checks the platform's character limits before publishing with approval.

Skill for Claude CodeCodex

Written for Claude Code: shipped in a Claude Code plugin.

Part of the x-skills plugin — 10 skills shipped together

Good fit Use it to turn a topic or rough sentence into a single post or short thread, choose an appropriate opening style, humanize the wording, and prepare it for publication.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sergebulaev/x-skills/x-post-writer
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.

Any agent
npx skills add sergebulaev/x-skills --skill x-post-writer
Clone the repo
git clone --depth 1 https://github.com/sergebulaev/x-skills

Made for: Claude Code, Codex.

Or install x-skills, the plugin that ships this one along with the rest of its 10 skills.

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 x-post-writer

README.md
[![agentmods](https://agentmods.dev/badge/skills/sergebulaev/x-skills/x-post-writer/github.svg)](https://agentmods.dev/skills/sergebulaev/x-skills/x-post-writer)
Your own site
<a href="https://agentmods.dev/skills/sergebulaev/x-skills/x-post-writer"><img src="https://agentmods.dev/badge/skills/sergebulaev/x-skills/x-post-writer/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.

agentmods 80×15 button for x-post-writer

Your own site · 80×15
<a href="https://agentmods.dev/skills/sergebulaev/x-skills/x-post-writer"><img src="https://agentmods.dev/badge/skills/sergebulaev/x-skills/x-post-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 120 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,735 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00120 $0.01735
Opus 5 $0.00060 $0.00868
Sonnet 5 $0.00024 $0.00347
Haiku 4.5 $0.00012 $0.00173

Measured today against content hash cd8479b254a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

x-post-writer 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 today.

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.

.codex-marketplace/x-skills/skills/x-post-writer/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

X Post Writer

Ship a single tweet, or a tight 2-3 tweet micro-thread, using hook shapes that actually travel on X in 2026. Single-tweet formulas land a complete punch in the first line, because X has no "see more" fold.

When to use

  • User says "write me a tweet about X"
  • User has a topic or a rough one-liner and wants a sharper hook
  • User wants to pick a proven single-tweet shape and fill in their voice
  • User wants a quick draft that auto-publishes on approval

Formulas this skill uses (single-tweet shapes)

Code Formula Primary goal Best for
X1 One-Liner Contrarian reposts a sharp, defensible against-the-grain take
X2 Data-Point Hook bookmarks one odd-precision number that reframes a thing
X3 Build-in-Public Confession replies a real metric from your own work, ugly ones included
X4 Quote-Tweet Dunk-with-Value reposts adding a layer to someone else's take (quote tweet)
X5 Mini-List Tweet bookmarks a scannable list that fits in one tweet
X6 Relatable Cold-Open likes a specific shared moment, no setup
X11 Third-Person Case-Study Flex reposts someone else's absurd, specific result as anyone-could-copy bait

Full skeletons in ../../references/hook-formulas.md. For long-form tweetstorms (X7-X10), use x-thread-builder. X11 was validated as the top-recurring winning shape in a ~450-tweet corpus (July 2026); prefer it over a first-person "How I" when the result you are citing is someone else's.

Pick by goal first

Goal Reach for
Replies X3, X1
Reposts X1, X4, X11
Likes X6
Bookmarks X2, X5, X11

Steps

Voice profile first (all drafts). If ../../references/voice-profile.md has filled: yes, load it and match the user's voice fingerprint, hard rules, and CTA/link style throughout. If it is not filled, mention once that x-humanizer --mode profile can learn their voice from a few posts, then proceed with the generic voice rules.

Read the full file on GitHub · 123 lines

Files

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.

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. today Changed cd8479b254a4
  2. 3d ago Changed · +6 lines 9600227c4aa7
  3. 10d ago First seen · 117 lines · 120 tokens per session scan A 4ce4c73c97f6

Subscribe to this mod's changes

x-post-writer is a skill published in the GitHub repository sergebulaev/x-skills (66 stars, last pushed yesterday), licensed MIT. It adds 120 tokens to every session and 1,735 once invoked, about $0.0006 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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