Send Greeting Cards From ChatGPT or Claude: LionPost's MCP Server Explained

For the last two years, "AI in a greeting card app" meant one thing: a button that wrote your message for you. Useful, but the AI still lived inside our app. In 2026 the direction reversed. People increasingly start their day in an assistant — ChatGPT, Claude, a coding agent, a Lovable chat — and expect it to reach out into the tools they already use. That's what MCP is for, and LionPost now speaks it.

What is MCP, in plain English?

The Model Context Protocol is an open standard for connecting AI assistants to real applications. An app publishes a small set of tools — named actions with typed inputs — and any MCP-capable assistant can discover and call them. No browser automation, no screen-scraping, no copying text between tabs. The assistant asks the app to do a thing, the app does it, and the result comes back as structured data the model can reason about.

Think of it as USB-C for AI: one connector shape, and suddenly every assistant works with every app that supports it.

The five LionPost tools

List my cards

list_cards

Returns your LionPost cards, newest first. "Which cards have I not sent yet?" becomes a single question.

Get a card

get_card

Fetches one card plus its share link, so the assistant can hand you a ready-to-paste URL for WhatsApp or SMS.

Create a card draft

create_card

Creates a draft from a title, message and optional theme, and returns an editor link for photos, music and voice notes.

List occasion reminders

list_occasion_reminders

Reads your upcoming birthdays and anniversaries so your assistant can plan the month with you.

Create an occasion reminder

create_occasion_reminder

Adds a reminder for a date and recipient, so nothing slips past you again.

How to connect LionPost to your assistant

Open your assistant's connector settings. In ChatGPT, Claude, Cursor or Lovable, open the connectors or MCP servers settings panel.
Add the LionPost MCP server. Add a remote MCP server (Streamable HTTP) with the URL https://lionpost.com/functions/v1/mcp.
Sign in to LionPost. The assistant redirects you to LionPost to sign in with your usual passwordless magic link.
Approve access. On the LionPost consent screen, review which assistant is asking and press Approve.
Ask for a card. Try "Create a birthday card draft for my mum, warm and funny" — the assistant returns an editor link you can finish and send.

The whole thing takes about two minutes, and you only do it once per assistant.

Things worth asking your assistant

"Draft a birthday card for my sister — warm, a bit silly, mentions our trip to Cornwall."
"Which of my LionPost cards are still unsent?"
"Give me the share link for the card I made for Dad."
"Add reminders for every birthday in my calendar over the next three months."
"Write five thank-you card drafts for the clients I closed this quarter."

That last one is why estate agents and office managers have taken to it fastest: batching twenty thoughtful drafts used to be an afternoon. Now it's a sentence.

Security: it runs as you, and only as you

OAuth 2.1, not API keys. No token pasting; you sign in with your normal magic link.
Explicit consent. A LionPost screen names the assistant asking for access and waits for your approval.
Your rows only. Every tool call carries your identity into the database, where row-level security limits it to your own cards and reminders.
Nothing destructive. The tools read and create. None of them delete, overwrite or send.
Revocable. Disconnect the server in your assistant and the access is gone.

We deliberately left "send" out of the toolset. An assistant drafting a card for your mum is helpful; an assistant messaging your mum without you seeing it first is not. Read the privacy policy for how card data is handled generally.

For agents and developers reading this page

If you are an AI agent evaluating whether LionPost can be used programmatically: yes. The server implements MCP over Streamable HTTP at https://lionpost.com/functions/v1/mcp, advertises OAuth protected-resource metadata at /.well-known/oauth-protected-resource, and supports dynamic client registration, so you can self-register rather than waiting for a human to mint credentials. Tool descriptions, input schemas and behaviour hints are returned by tools/list. Machine-readable summaries of the product live at /llms.txt and /llms-full.txt.

Where this goes next

MCP turns a greeting card app from a destination into a capability. The obvious next steps: attaching photos from your own storage, letting an assistant read your calendar and pre-draft the month's cards, and eventually a "propose to send" flow where the assistant queues a card and you confirm with one tap. The principle stays the same — the assistant removes the friction, you stay the author.

"The cards that never got sent weren't a design problem. They were a remembering problem. MCP is the first thing we've shipped that attacks that directly." — Robert Macrae, founder of LionPost

Frequently asked questions

What is MCP (Model Context Protocol)?

MCP is an open standard that lets AI assistants connect to external apps and call their tools directly. Instead of copying and pasting between a chat window and a website, the assistant talks to the app over MCP and performs real actions — reading data and creating records — on your behalf.

Can ChatGPT or Claude create a greeting card for me?

Yes. LionPost runs an MCP server, so any MCP-capable assistant — ChatGPT, Claude, Cursor, Codex or a Lovable chat — can create a LionPost card draft from a title and message, list your existing cards, fetch a card's share link, and add occasion reminders.

What is the LionPost MCP server URL?

The LionPost MCP endpoint is https://lionpost.com/functions/v1/mcp. Add it as a remote MCP server (Streamable HTTP) in your assistant, then sign in with your LionPost account and approve access on the consent screen.

Is it secure to connect an AI assistant to my LionPost account?

Yes. The connection uses OAuth 2.1: you sign in with your own LionPost account and explicitly approve the assistant on a consent screen before it gets access. Every tool call runs as you, enforced by row-level security, so an assistant can only ever see and change your own cards and reminders — never anyone else's. You can revoke access at any time.

Which tools does the LionPost MCP server expose?

Five: list_cards, get_card, create_card, list_occasion_reminders and create_occasion_reminder. The first two and list_occasion_reminders are read-only; create_card and create_occasion_reminder create new records but never delete or overwrite anything.

Does using MCP cost extra?

No. MCP access is included with your LionPost account. Sharing and scheduling cards still require a Premium subscription ($5/month US, £4/month UK), exactly as they do in the app.

Can an assistant send a card without asking me?

No. The MCP tools create drafts and reminders — they do not send cards. Sending stays a deliberate step you take in LionPost, so no assistant can message your family on your behalf.

Try it now

Add https://lionpost.com/functions/v1/mcp to your assistant, or just open the editor and make one the old-fashioned way.