One post, six social networks, one sentence

What it is and why it matters

Publishing the same post on six social networks by hand means opening six apps, uploading the same slides six times and rewriting the caption six times. Every day. It's the first job that gets dropped when you have a product to build.

The answer isn't connecting Claude Code to each network one by one. The official APIs come with heavy rules: TikTok, for example, only lets you post privately until it approves your app. The trick is a post scheduler that has an MCP server. MCP is the standard way Claude Code connects to an outside service: a plug.

The result: you give it the slides, the caption and the time, and it schedules everything, platform by platform. With some schedulers you ask it the next day how it went and it answers with the numbers. It's for anyone who publishes alone and wants to be everywhere without spending the evening on it.

1. Pick the scheduler

Several have an official MCP server. Three things change: where it runs, whether it's free and whether it gives you the numbers. Postiz, Upload-Post and Buffer all cover the six networks in this guide.

• Postiz. It's open source: you install it for free on your own server (with Docker, for example), or you use Postiz Cloud, which is a subscription with a free trial. Both versions have the MCP server. The MCP server has no tool for reading statistics: you check those in the app.
• Upload-Post. Cloud only, with a free plan that has limits, for example on how many files you upload per month. Its MCP server has tools to upload photos, videos and text posts, to schedule, and to read statistics and comments.
• Buffer. Cloud, and it connects with your Buffer account without a key: you log in and approve (that's called OAuth). It schedules posts and gives you aggregated metrics. The limits depend on your plan: check yours.
• Blotato. Paid only: its documentation says API and MCP access isn't included in the free trial, and that generating a key during the trial ends the trial and starts the subscription.
• Ayrshare. Built for developers. It has no free plan, only a trial, and every plan includes the API. It also handles comments and messages. For X you have to add your own X credentials.

2. Connect it to Claude Code

First you connect your social accounts inside the scheduler, on its website: that's where you log in to TikTok, Instagram and the rest. Claude never sees your passwords, only the accounts you connected.

Then you add its MCP server with one command in the terminal, outside Claude Code. With --scope user it works in all your projects. YOUR_KEY is the service's API key: in Postiz it's in the developer settings (Public API), in Upload-Post on the API Keys page.

# Postiz Cloud
claude mcp add --transport http postiz --scope user https://mcp.postiz.com/mcp --header "Authorization: Bearer YOUR_KEY"
# Buffer (then /mcp to log in)
claude mcp add --transport http buffer --scope user https://mcp.buffer.com/mcp
# Upload-Post
claude mcp add --transport http upload-post --scope user https://mcp.upload-post.com/mcp --header "Authorization: ApiKey YOUR_KEY"
# Blotato (then /mcp to log in)
claude mcp add --transport http blotato --scope user https://mcp.blotato.com/mcp
# Ayrshare
claude mcp add --transport http ayrshare --scope user https://api.ayrshare.com/mcp --header "Authorization: Bearer YOUR_KEY"

Postiz on your own server: same command, but the address is your Postiz followed by /mcp. The MCP server runs inside the Postiz backend, so if you have a reverse proxy (Caddy or Nginx, for example) it has to let that path through.

1. Check from the terminal with claude mcp list: the scheduler should show as connected.
2. For Buffer and Blotato, open Claude Code, type /mcp, pick the server and log in through the browser.
3. Test it: “Which social accounts do you see in the post scheduler? List them with their platform.” If the list is right, you're ready.

3. The platforms' real limits

• TikTok, unapproved app. Until TikTok has reviewed the app (it's called an audit), posts only go out privately (SELF_ONLY), for at most five users in 24 hours, and those accounts must be private. If you install Postiz yourself, you create the TikTok app and have to get it approved: Postiz itself warns that with Meta, YouTube and TikTok it can take a few weeks.
• TikTok, carousel. A photo post through the API can hold up to 35 images. The title stops at 90 characters, the description at 4000. The API also has a second mode: instead of publishing, it sends the post to your TikTok inbox and you finish it in the app.
• No native scheduling. Neither TikTok's API nor Instagram's has a field for the time: the scheduler holds the post and publishes it at the right moment. That's why you need a service that's always on, not your laptop.
• Instagram. You need a professional account. A carousel can hold up to 20 items, images must be JPEG, and they're all cropped to match the first one (square by default): make all the slides the same size. There's also a limit on posts published through the API in 24 hours, but the official page gives two different numbers: check your account's limit.

The test to run before you trust it: schedule a TikTok post ten minutes from now and check on your phone that it went out, and that it's public.

4. Your first post on six networks

Put the slides in a folder, numbered in order (01.jpg, 02.jpg…), and the caption in a file. Then, in Claude Code:

Use the connected post scheduler. Schedule the carousel with the images in the folder [folder], in name order, for 6:00 pm today, my local time, on TikTok, Instagram, YouTube, X, Threads and LinkedIn. The caption is in the file [file].
First check each platform's rules: how many images it accepts, which format, how many characters. If a platform doesn't accept the carousel as it is, skip it and tell me what it would need.
Before scheduling, show me the summary, platform by platform, and wait for my OK.

The summary and the OK aren't a detail: some tools can publish right away instead of scheduling, and Buffer itself recommends keeping approval prompts on.

5. One caption per network, and yesterday's numbers

The exact same caption on six networks works badly: on X the first line is what counts, on LinkedIn people read more. Have it adapted:

Take the caption in the file [file] and write one version per platform: TikTok (title under 90 characters, then the description), Instagram, YouTube, X (short, strongest sentence first), Threads and LinkedIn (more relaxed, first person). Same content, no new facts, no strings of emoji. Show me the six versions one below the other, then use them to schedule the 6:00 pm post.

The next day, ask for the numbers. It works if your scheduler has statistics tools: Upload-Post, Buffer and Ayrshare do, the Postiz MCP server doesn't.

How did yesterday go? For every post published yesterday give me views, likes, comments and shares, platform by platform, in a table. Then tell me which one did best and what it had that the others didn't. If a number isn't available, write “not available”: don't estimate it.

Common mistakes

• Connecting Claude Code straight to each network's API. You end up managing six apps to get approved, and on TikTok you post privately until you pass the audit.
• Adding the server with --scope project and the key inside. It ends up in the project's .mcp.json file, which usually goes into git: use --scope user or the default local scope.
• Trusting it without a test. Schedule the first post ten minutes out and check that it goes out, and that it's public on TikTok.
• PNG slides, or slides of different sizes, for Instagram. Through the API it only accepts JPEG, and it crops every slide to match the first.

Checklist

• My social accounts are connected inside the scheduler
• claude mcp list shows the scheduler as connected
• My Instagram account is a professional account
• I ran a test post on TikTok and it went out public
• The slides are JPEG, all the same size, numbered in order
• Claude shows me the summary and waits for my OK before scheduling

Frequently asked questions