If you’ve ever searched for an API to send greeting cards programmatically, you’ve probably noticed the pickings are slim. Most card platforms are built for humans clicking through forms — not for developers, AI agents, or apps that need to trigger a card the moment something happens in their system.
Greetu solves this with an MCP server (Model Context Protocol) — a modern, JSON-RPC API that any AI assistant or application can call to create, schedule, and track greeting cards.
One Endpoint, Six Tools
Everything lives at a single endpoint:
plain
POST https://greetu.io/api/mcpAuthenticate with your API key (
X-API-Key: grtu_...), and you get six tools:Table
| Tool | What it does |
|---|---|
greetu.create_card | Create a card with a custom or AI-generated message |
greetu.schedule_card | Schedule a card to unlock at a future date/time |
greetu.list_cards | List recently created cards |
greetu.get_replies | Fetch text replies left on a card |
greetu.get_reactions | Fetch emoji reactions on a card |
greetu.reply_to_card | Reply to a card programmatically |
Your First API Call
Creating a card takes one request:
bash
curl -X POST https://greetu.io/api/mcp \
-H "Content-Type: application/json" \
-H "X-API-Key: grtu_xxxxxxxx" \
-d '{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "greetu.create_card",
"arguments": {
"recipient_name": "Sarah",
"occasion": "birthday",
"use_ai_message": true
}
}
}'The full schema gives you control over the card:
recipient_name, sender_name, occasion, theme, a custom message (or use_ai_message to let AI write it), a locked_until date for time-capsule reveals, and even a Base64-encoded voice_message.Works With Any AI Assistant
Because it’s MCP, you don’t have to write raw HTTP at all. Drop the server config into Claude Desktop, ChatGPT, Cursor, or VS Code, and your assistant can create cards from plain conversation:
“Create a thank-you card for every client who signed this month, scheduled for the first Friday.”
The assistant calls the tools for you. Greetu is also one of the first card platforms built for AI agents directly — any MCP-compatible agent can send cards on your behalf.
Built for Automation Triggers
The obvious use cases write themselves:
- CRM event → closed deal fires a welcome card
- Date match → birthday triggers
greetu.schedule_cardovernight - Support ticket resolved → thank-you card with AI-written message
- Card opened →
greetu.get_reactionspulls the response back into your system
Unlike email APIs, cards feel like a gesture, not a notification — which is exactly why they work for retention, reviews, and referrals.
Getting Started
- Get an API key at greetu.io/mcp
- Point your MCP client (or your code) at the endpoint
- Call
tools/listto explore the schemas - Send your first card
Free to start, with volume tiers for businesses sending at scale.
👉 Get your API key and full docs: greetu.io/mcp