Publish to social media with an MCP server

What does the MCP connection do?

MCP gives a compatible assistant structured tools for working with your social accounts. Mellow Hub’s endpoint is https://www.mellow.world/mcp. It uses Streamable HTTP and supports OAuth authorization or an owner-created key. The REST API starts at /api/hub/v1.

Your assistant needs support for remote MCP servers. In ChatGPT, Claude, Cursor or another client, availability and setup depend on that client’s plan and configuration. Pasting a prompt alone does not grant account access. The account owner must connect channels and approve the access being delegated.

Connect, validate, publish, verify

1. Connect the channels as a person. Open Channels and complete each platform’s authorization. An agent can return a connection link; it cannot give itself control of an account.
2. Choose the delegation. In Agents, limit access to the required channels, choose review or autopilot, and set an expiry and daily ceiling. Use the client’s OAuth flow when available.
3. Read the actual permissions. Call whoami, then list_channels and list_platforms. Use returned channel IDs; do not guess an account identifier from a username.
4. Prepare the media and validate. Register reachable media or request an upload URL. Call validate_post before create_post. Validation reports issues without publishing anything.
5. Submit within the delegation. Include a stable idempotency key and, when scheduling, an ISO 8601 scheduledAt timestamp. In review mode, the post waits for the owner’s approval.
6. Read every destination. Call get_post and inspect targets. A request being accepted is different from a platform publishing it. Record the confirmed link or the channel’s error.

Which social networks are supported?

The current registry has 10 platform identifiers: Instagram, TikTok, TikTok Business, YouTube, X, LinkedIn, Threads, Bluesky, Pinterest, Facebook. TikTok and TikTok Business are two integration modes for the same social network. Availability depends on provider enablement, account eligibility and a completed connection.

The table below comes from Mellow’s validation registry. It describes the rules this service checks, not a guarantee that every possible account and format has passed an end-to-end publication test.

Read the full platform rules for required fields and placements, or use the API reference for payloads, tool contracts and worked examples.

For Instagram account eligibility, the two login paths and photo/carousel/Reel inputs, follow the Instagram MCP guide.

How to avoid duplicate posts and silent failures

Try a draft in the free post checker, or follow the REST scheduling recipe for concrete requests and response checks.

If a request times out, retry the same task with the same idempotency key. Generating a fresh key creates a different request and can produce a duplicate. Reusing a key with different content is refused.

Several targets can succeed while another fails. The overall result can be partial, so always inspect the target results. Validation catches known input problems; it cannot guarantee that a provider will stay available or that a platform will accept a post later.

The owner can review the action journal and revoke access in Agents. Revocation takes effect on the next request. A key cannot create another key or approve its own post.

When should I choose Hub or the Mellow app?

Choose Hub for an agent-driven or manual workflow across several networks, using shared channel connections and per-network results. Choose Mellow’s Instagram planner for an individual creator’s calendar, grid and assistant on iPhone or the web.

Both products share a login and subscription. A Hub post sent to several networks uses the publication allowance per destination. See current plans before setting up a recurring workflow.