Build Your First Remote Plugin

Step-by-step guide to creating your first ThreeU plugin.

Step 1: Create Developer Account

Apply at developer.threeu.app. Once approved, activate via the invitation email.

Step 2: Create the Project

A plugin is a service you host. Start a Node project and install the SDK (the CLI has no generator today):

Setup

Shell

mkdir fastship && cd fastship
npm init -y
npm install threeu-sdk express

Step 3: Define Manifest

Edit threeu.config.ts:

threeu.config.ts

TypeScript

import { definePlugin } from "threeu-sdk/plugin";

export default definePlugin({
  name: "FastShip",
  slug: "fastship",
  type: "plugin",
  category: "shipping",
  permissions: ["orders:read", "shipping:write"],
  provider: {
    type: "remote_http",
    baseUrl: "https://api.fastship.com/threeu",
    actions: {
      "shipping.get_rates": { method: "POST", path: "/rates" },
      "shipping.create_shipment": { method: "POST", path: "/shipments" }
    }
  }
});

Step 4: Implement /health

Every plugin needs a health endpoint:

Health Endpoint

TypeScript

const express = require("express");
const app = express();

app.get("/health", (req, res) => {
  res.json({ status: "ok", version: "1.0.0",
    timestamp: new Date().toISOString() });
});

app.listen(3000);

Step 5: Implement Action

Add the action endpoint:

Action Endpoint

TypeScript

app.post("/rates", (req, res) => {
  verifySignature(req, process.env.WEBHOOK_SECRET);
  const { order, destination } = req.body;
  res.json({
    success: true,
    rates: [
      { service: "standard", price: 15, currency: "QAR", estimated_days: 5 },
      { service: "express", price: 35, currency: "QAR", estimated_days: 2 }
    ]
  });
});

Step 6: Configure & Test

Log into developer.threeu.app, paste your manifest JSON in the Integration tab, test health check, trigger a gateway action, and inspect logs.

Step 7: Submit for Review

Click "Submit for Review" when your plugin is ready. ThreeU reviews for security, reliability, and quality.

Permissions

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