X (Twitter) MCP Server

Q: Can it post Twitter threads?

Not as a reply chain. The x-thread-generator skill still writes the thread, then offers three ways to ship it: publish the first post and paste the rest as replies yourself, collapse it into one long post if your account has X Premium, or schedule the parts as standalone tweets over several days.

Your AI agent writes, posts and schedules tweets with images, GIFs or video through X's official API.

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3 min setup

Updated Nov 5, 2026

Connect in a minute

In Claude, open Customize → Connectors → Add custom connector and paste:
Connector URL
```
https://postonce.to/mcp
```
Choose Register automatically, select Add, then Connect and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Claude guide →

Turn on Developer mode, then create an app in Plugins with this URL:
Server URL
```
https://postonce.to/mcp
```
Choose OAuth with automatic registration and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

ChatGPT guide →

Install the plugin. It adds the server and the skills below.

Terminal

claude plugin marketplace add postoncehq/plugins
claude plugin install x-mcp@postoncehq

Run /mcp, pick the postonce server, choose Authenticate and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Claude Code guide →

Add the server:

Terminal

codex mcp add postonce --url https://postonce.to/mcp

Sign in to PostOnce in the browser that opens:
Terminal
```
codex mcp login postonce
```
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Codex guide →

Merge into ~/.cursor/mcp.json:

~/.cursor/mcp.json

{
  "mcpServers": {
    "postonce": {
      "url": "https://postonce.to/mcp"
    }
  }
}

In Cursor Settings → MCP, select Connect next to postonce and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Cursor guide →

Add a remote server:

Connection

URL: https://postonce.to/mcp
Transport: Streamable HTTP
Auth: OAuth (sign in with PostOnce)

No OAuth in your client? Send Authorization: Bearer with a key from Preferences → API keys (paid plans only).
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

All integrations →

What your agent can do

Ask your agent toHow it works

Publish a tweet now (up to 280 characters, or 4,000 if the account had X Premium when you connected it)create_post on your connected X account

Schedule a tweet for latercreate_post with publish_at

Post up to 4 images, or 1 GIF, or 1 video (up to 2 minutes without Premium)create_upload_url, upload, then create_post with media

Save a draft to finish latercreate_draft

Check whether a tweet went out, and get its URLget_post

Change or cancel a scheduled tweetupdate_post, cancel_post

Post the same thing to X and other platformsAdd more targets to create_post (LinkedIn, Instagram, TikTok, YouTube, Threads, Facebook, Pinterest, Bluesky)

Not supported: threads as reply chains, replies, quote posts, polls, reading your timeline or mentions, analytics, DMs, and editing or deleting tweets that are already published. Text over the character limit is cut off, not rejected, so keep each post within it. This server publishes; it doesn't browse X for you.

X skills

Your agent writes for the platform before it posts. In the plugin, free on GitHub.

x-tweet-generatorWrites single tweets in your voice: a first line that earns the stop, one idea, within 280 characters (or 4,000 for Premium accounts).
x-thread-generatorTurns a topic, blog post or transcript into a 5–15 post Twitter thread, then gives you a way to publish it that actually works with this server.
x-bio-generatorWrites a 160-character X (Twitter) bio, display name and pinned tweet idea for you to paste into your profile.
x-tweet-formatterFormats tweets: line breaks, Unicode bold and italic (with their accessibility and search costs), and splitting text that's over the limit.
x-content-calendarPlans 1–4 weeks of tweets from your goals or a source you want to repurpose, drafts each one and schedules them on approval.
postoncePublishing workflow: pick the right account, upload media, schedule, and confirm the post actually went live.

x-mcp on GitHub

Try these prompts

Turn this blog post into a tweet with the chart attached and post it tomorrow at 10am.
Write five tweet options about our launch and schedule the best one for 9am.
Plan a week of tweets from this podcast transcript and schedule one a day.

X MCP questions

Is there an official X (Twitter) MCP server?

This server uses X's official API through PostOnce, with the OAuth permissions you grant when you connect. You don't need your own X API access.

Can Claude post tweets?

Yes, once it's connected to an MCP server that can publish, like this one. Claude writes the tweet, then calls create_post. It can post now or schedule for later.

Is it safe for my X account?

Yes. Tweets go through X's official API with the permissions you grant when you connect. Many Twitter MCP servers on GitHub drive a logged-in browser session or call unofficial, scraped endpoints instead, which X's terms don't allow and which can get accounts restricted or suspended.

Do I need an X developer account or API key?

No. PostOnce holds the X API access; you just connect your account.

Can it post Twitter threads?

Not as a reply chain. The x-thread-generator skill still writes the thread, then offers three ways to ship it: publish the first post and paste the rest as replies yourself, collapse it into one long post if your account has X Premium, or schedule the parts as standalone tweets over several days.

Can it post long tweets?

Yes, up to 4,000 characters if your account had X Premium (blue check) when you connected it to PostOnce. Otherwise the limit is 280. If you subscribe to Premium later, reconnect the account.

Is it free?

The skills are free and MIT-licensed on GitHub. Publishing runs through a PostOnce account, which you can try free for 7 days without entering a card. After that, see pricing.

Can I post to X (Twitter) from my own code?

Yes. The same publishing works through the PostOnce social media posting API with an API key on any paid plan.

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