x-skills: A Claude Code Skill for Writing X Posts in Your Own Voice

Most AI writing tools default to one register: rounded, hedge-everything, LinkedIn-flavored. That works fine on LinkedIn. It reads wrong on X, where the format punishes throat-clearing and rewards a sharp first line. x-skills is a Claude Code skill for writing X posts that is built specifically for that shorter, punchier register instead of trying to bend a general-purpose writing prompt into working for it.

Built by developer Serge Bulaev, x-skills is a free, open-source (MIT licensed) skill bundle for Claude Code and Codex. It installs as a set of nine skills that activate automatically when someone asks Claude to help with a tweet, a thread, a reply, or a content plan for X.

What x-skills actually does

The bundle is not a single prompt. It is nine specialized skills, each scoped to one job:

• Post Writer drafts a single tweet or short auto-thread using a hook formula matched to a stated goal (replies, reposts, likes, or bookmarks), and respects the 280-character limit (25,000 on X Premium).
• Thread Builder structures longer tweetstorms: listicle, story, curiosity-gap, or how-I-did-it teardown, with the opening tweet built as a promise plus an open loop.
• Humanizer strips out em dashes, stock AI vocabulary ("leverage," "delve," "harness"), rule-of-three lists, and the flat rhythm that makes AI-written tweets recognizable at a glance. It also runs a pre-publish audit mode that checks character count, hook strength, and hashtag and link placement.
• Hook Extractor reverse-engineers the opening line of any viral tweet or thread and maps it to one of eleven documented hook formulas, then hands back a blank template.
• Reply Drafter writes a reply or a value-add quote tweet for a given tweet URL.
• Content Planner builds a week's posting plan: single-tweet versus thread mix, per-day hooks, timing, and reply targets.
• Repurposer takes content from another platform (a LinkedIn post, a blog draft, a video script) and re-hooks it for X's no-fold first line instead of just trimming it to fit.
• Profile Optimizer rewrites a bio, header, and pinned tweet for discoverability.
• Audience Insights pulls real engagement data on a niche or a specific account via Apify, no login required, to show what is actually working before a post gets drafted.

Every skill applies the same six voice rules by default: no em dashes, names always capitalized, no AI-vocabulary words, specific numbers over vague adjectives, one idea per tweet, and hard limits on hashtags and emoji. That consistency across nine separate skills is the part worth noting: it means a thread drafted by one skill and a reply drafted by another still sound like the same account.

How someone would actually use this claude code skill for writing x posts

Installation is a one-line command through the Claude Code or Codex plugin systems (/plugin install x-skills@x-skills in Claude Code, or the equivalent codex plugin add command), or by adding the repo directly from the Skills panel in claude.ai or Claude Desktop. No coding is required to use it day to day.

Once installed, the workflow is conversational: "Write a tweet about why most AI agents fail on retries, not reasoning," or "Turn my notes into a thread on how we cut agent latency from 9 seconds to 2.1." The relevant skill activates on its own, drafts the post, and stops. Nothing publishes automatically. Every draft is held for review before it goes anywhere, which matters for anyone using this for a real personal or company account rather than a throwaway test.

Publishing itself is optional and separate from drafting. By default, x-skills hands back copy-paste-ready text. If someone wants Claude Code to post directly, the repo connects to Publora, a third-party publishing API, through a short setup involving an API key and a .env file. That step is genuinely optional. The writing and strategy skills work the same with or without it, and replies always come back as copy-paste text regardless, since X has no native reply endpoint through Publora.

Who this is genuinely for

This tool is for someone drafting their own X presence with an agent instead of a human ghostwriter: an individual builder, operator, or small team posting regularly and tired of every draft coming out sounding like a press release. The Hook Extractor and Audience Insights skills in particular are useful for anyone trying to study what already works in a niche before writing into it, rather than guessing.

It is not a content strategy in a box. The skill drafts based on formulas and voice rules, not on deep familiarity with a specific person's history or judgment calls about what is worth saying. It still needs a human to supply the actual ideas, catch anything factually off, and decide what is worth posting. Anyone expecting a fully autonomous ghostwriter will be disappointed; anyone treating it as a fast first draft with the AI-tell problem already handled will get real use out of it.

The honest traction picture

x-skills is a small, early project. As of this writing it sits at 44 GitHub stars, up from 28 a day earlier in the scan that first flagged it, a fast proportional climb but still a modest number in absolute terms. It was created in early July 2026 and has an active commit history since, with six forks and no open issues at the time of writing. It is part of a small family of sibling repos from the same author covering LinkedIn, Instagram, YouTube, TikTok, Threads, and Facebook, all sharing the same voice engine and approve-before-publish pattern; the LinkedIn version is the most established of the set.

None of that adds up to a proven-at-scale tool. It adds up to a young, actively maintained, single-purpose skill worth trying for what it specifically does well: writing in X's register instead of LinkedIn's, with the AI tells stripped before a human ever sees the draft.

Source: github.com/sergebulaev/x-skills.