Vellum custom MCP server OAuth or API key

Post to Social Media with Vellum TikTok, Instagram, YouTube and more, from your open-source assistant

Add Upload-Post to Vellum Assistant with two terminal commands
Publish, schedule and read analytics just by asking
Works whether your assistant runs on your own machine or on Vellum Cloud

Step 1: run this where your assistant runs

Terminal

# 1. Add the Upload-Post MCP server
assistant mcp add upload-post -t streamable-http -u https://mcp.upload-post.com/mcp

# 2. Sign in with OAuth (no API key needed)
assistant mcp auth upload-post

No API key needed. Sign in to Upload-Post when the auth command asks you to approve access.

How to connect Upload-Post to Vellum Assistant

Two commands and one sign-in. It takes about two minutes.

Step 1

Add the MCP server

Run assistant mcp add upload-post -t streamable-http -u https://mcp.upload-post.com/mcp. You can also add it from the Vellum Assistant settings.

Step 2

Sign in with OAuth

Run assistant mcp auth upload-post and approve access with your Upload-Post account on app.upload-post.com. No API key needed.

Step 3

Or use an API key

Prefer a key? Create one in app.upload-post.com under API Keys and add the server with -H "Authorization: ApiKey YOUR_API_KEY".

Step 4

Ask your assistant

Send the first message below. Vellum lists your Upload-Post profiles with their connected accounts. From then on, just ask it to post.

API key instead of OAuth

Terminal

assistant mcp add upload-post -t streamable-http \
  -u https://mcp.upload-post.com/mcp \
  -H "Authorization: ApiKey YOUR_API_KEY"

Then send this to your assistant

First message

You now have the Upload-Post MCP server (upload-post). Follow these rules:

- Use it for every request about posting, scheduling, analytics, comments or DMs on my social media accounts.
- Before you publish, schedule, reply or send a DM, show me the caption, the accounts and the date and time, and wait for my OK.
- After publishing, check the upload status and tell me the result for each platform.

To start, list my Upload-Post profiles and the social accounts connected to each.

Custom MCP server: Upload-Post is not a Vellum plugin. You add it yourself as an MCP server with the commands above. Setup details and auth options are in the MCP server docs.

What can Vellum do with Upload-Post?

Every capability maps to documented Upload-Post tools. Your assistant picks the right one from your request.

Just ask in plain language

Tell your assistant what to post, where and when. It picks the right Upload-Post tool for the job.

Publish anywhere

Upload videos, photos and text to TikTok, Instagram, YouTube, LinkedIn, Facebook, X, Threads, Pinterest, Reddit, Bluesky and Google Business.

Schedule and queue

"Post this tomorrow at 6pm" becomes a scheduled post. Vellum can also add posts to your queue and check their status.

Read analytics

Ask which posts performed best this week and get the numbers from your connected accounts.

Comments and DMs

Read new comments, draft replies and handle direct messages from the same conversation.

Media and FFmpeg

Stage media files and trim, convert or re-encode video with the FFmpeg tools before it goes out.

What is Vellum Assistant?

Vellum Assistant is an open-source personal AI assistant with long-term memory. You can run it yourself for free or use it on Vellum Cloud, and reach it from your phone, your desktop or the chat apps you already use.

Open source under the MIT license: github.com/vellum-ai/vellum-assistant
Long-term memory, so it keeps context from one conversation to the next
Runs locally for free, or on Vellum Cloud with paid plans
Available on macOS, iOS, Android, the web, voice, email, Telegram, Slack and the terminal
Adds MCP servers with the assistant mcp commands or from its settings

What is the Upload-Post MCP?

The Upload-Post MCP is a hosted Model Context Protocol server that gives AI agents your connected social accounts as tools. It is the same server behind our ChatGPT, Claude and OpenClaw integrations.

Add the Upload-Post MCP URL with one command
Sign in with OAuth 2.1, or pass an API key as a header
Vellum discovers your profiles and connected accounts
Tools for uploads, status, scheduling and queue, analytics, profiles, pages and boards, comments, DMs, media staging and FFmpeg
Open source: github.com/Upload-Post/upload-post-mcp

Vellum MCP server

Name        upload-post
Transport   streamable-http
URL         https://mcp.upload-post.com/mcp
Auth        OAuth 2.1 (assistant mcp auth)
   or
Header      Authorization: ApiKey YOUR_API_KEY

What can you ask Vellum to post?

No commands to memorize. Just describe what you want.

Cross-post Instagram, TikTok, YouTube

“Post this clip to Reels, TikTok and Shorts tomorrow at 6pm.”

Analytics All connected accounts

“What were my best posts this week?”

Community Your last video

“Reply to new comments on my last video.”

Discover Upload-Post profiles

“List my Upload-Post profiles and the accounts connected to each.”

Why use Vellum for your social media?

A personal assistant that remembers your preferences and follows you across devices, with Upload-Post doing the publishing.

Tell it once

Vellum Assistant keeps long-term memory. Tell it your default accounts, tone and best posting times once, and ask it to use them for future posts.

Ask from where you are

You can talk to Vellum on your phone, on the web, over email, Telegram or Slack. The MCP server is added to the assistant, so ask for a post from the surface you use.

Local or cloud

Upload-Post is a hosted server at a public URL. Your assistant only needs internet access to reach it, whether it runs on your machine or on Vellum Cloud.

Can Vellum post on a schedule?

Yes. Vellum hands the schedule to Upload-Post, and Upload-Post publishes each post at the set time, even if your assistant is offline.

Batch a week

One request can create several scheduled posts, each with its own date, time and accounts.

Use your queue

Ask Vellum to add posts to your Upload-Post queue instead of picking every time by hand.

Check what is queued

Ask what is scheduled and Vellum reads it back from Upload-Post, so you can change plans before anything goes out.

Is it safe to let Vellum post for you?

You approve access with OAuth, and the first message tells your assistant to check with you before anything goes out.

OAuth sign-in with your Upload-Post account: with assistant mcp auth you never paste an API key into a chat
If you use an API key, it goes in the server header, not in your messages
Vellum only reaches the social accounts you already connected in Upload-Post
Upload-Post holds the platform connections, so your assistant never sees your social media passwords
Both sides are open source, so you can read the code of the assistant and of the MCP server

How does Vellum compare to other AI assistants?

The same Upload-Post server works everywhere. What changes is how you connect it.

Assistant	How you connect Upload-Post	Where it runs
Vellum Assistant	assistant mcp add with the MCP URL, then assistant mcp auth for OAuth, or an ApiKey header	Your machine or Vellum Cloud; macOS, iOS, Android, web, Telegram, Slack
OpenClaw	The Upload-Post skill on ClawHub, or openclaw mcp add with OAuth	Self-hosted on your machine, with messaging channels
Hermes Agent	MCP config block in config.yaml with your API key	Self-hosted, on your machine or server
Poke	poke.com/integrations/new with the MCP URL, OAuth or API key	iMessage, SMS, Telegram and WhatsApp
Claude	Add a custom connector with the MCP URL and sign in with OAuth	claude.ai and Claude Desktop

How much does it cost to use Vellum with Upload-Post?

The connector costs nothing extra.

Upload-Post connector

Free. The MCP server is open source and works with every Upload-Post plan.

Upload-Post free plan

10 uploads a month, no credit card. TikTok is not included on the free plan.

Vellum Assistant

Open source and free to run locally. Vellum Cloud has its own paid plans, set by Vellum.

Troubleshooting the Vellum MCP server

The five things that usually go wrong, and how to fix them.

The OAuth sign-in did not finish

Run assistant mcp auth upload-post again and approve access in the browser with the Upload-Post account that owns your connected social accounts. On a machine without a browser, add the server with the API key header instead.

Vellum does not see any Upload-Post tools

Check that the server was added with -t streamable-http and the exact URL https://mcp.upload-post.com/mcp, and that you completed the OAuth sign-in or set the header.

I get an unauthorized error with an API key

The header must read Authorization: ApiKey YOUR_API_KEY, with a key from app.upload-post.com under API Keys. Create a new key if the old one was deleted.

Vellum writes the post but does not publish it

Tell it to use the Upload-Post MCP server for every social media request, then repeat the request. Asking it to list your Upload-Post profiles first also helps.

A social account is missing

Connect that account to a profile at app.upload-post.com first, then ask Vellum "List my Upload-Post profiles again."

Use Upload-Post with other AI agents

One Upload-Post account, the same MCP server, any assistant.

OpenClaw Hermes Agent Poke Lindy Manus Claude ChatGPT OpenCode All AI agents MCP server

Frequently asked questions

Vellum + social media, answered. Last updated September 2026.

How does Vellum Assistant work with Upload-Post?

Upload-Post runs a hosted MCP server at https://mcp.upload-post.com/mcp. You add it to Vellum Assistant as an MCP server and sign in with OAuth. After that the assistant can publish, schedule and analyze posts on your connected social accounts.

How do I add Upload-Post to Vellum Assistant?

Run assistant mcp add upload-post -t streamable-http -u https://mcp.upload-post.com/mcp, then assistant mcp auth upload-post to sign in. You can also add the server from the Vellum Assistant settings.

Is there an official Upload-Post plugin for Vellum?

No. Vellum Assistant connects to any MCP server, so you add Upload-Post yourself as a custom MCP server with the commands on this page.

Do I need an Upload-Post API key for Vellum?

No. assistant mcp auth signs you in with OAuth 2.1. If you prefer a key, add the server with the header Authorization: ApiKey YOUR_API_KEY, using a key from app.upload-post.com under API Keys.

Does it work when Vellum runs locally and on Vellum Cloud?

Yes. Upload-Post is a hosted server at a public URL, so the assistant only needs internet access to reach it. The setup is the same in both cases.

Can I ask for a post from Telegram or Slack?

The MCP server is added to your assistant, not to one app, so you can ask for a post from the surface you use to talk to Vellum. Keep approval on for publishing so it checks with you first.

Which social media platforms can Vellum post to?

Any account you connect in Upload-Post: TikTok, Instagram, YouTube, LinkedIn, Facebook, X, Threads, Pinterest, Reddit, Bluesky and Google Business.

Is it free?

The connector is free. The Upload-Post free plan includes 10 uploads a month with no credit card; TikTok is not included on the free plan. Vellum Assistant is free to run locally, and Vellum Cloud has paid plans.