diff --git a/src/dienstService.js b/src/dienstService.js
new file mode 100644
index 0000000..6cf42a8
--- /dev/null
+++ b/src/dienstService.js
@@ -0,0 +1,24 @@
+const fs = require('fs')
+const path = require('path')
+
+let dienstenCache = null
+
+function loadDiensten() {
+  if (dienstenCache) return dienstenCache
+  const jsonPath = process.env.DIENSTEN_JSON
+  const raw = fs.readFileSync(jsonPath, 'utf-8')
+  dienstenCache = JSON.parse(raw)
+  return dienstenCache
+}
+
+function findDienst(dienstnummer) {
+  const diensten = loadDiensten()
+  return diensten.find(d => d.dienstnummer === dienstnummer) || null
+}
+
+function getPngFilePaths(dienst) {
+  const pngDir = process.env.DIENSTEN_PNG
+  return dienst.paginas.map(p => path.join(pngDir, p.bestandsnaam))
+}
+
+module.exports = { loadDiensten, findDienst, getPngFilePaths }
diff --git a/src/index.js b/src/index.js
new file mode 100644
index 0000000..8a9c0c7
--- /dev/null
+++ b/src/index.js
@@ -0,0 +1,31 @@
+require('dotenv').config()
+const express = require('express')
+const { handleWebhook } = require('./messageHandler')
+const { loadDiensten } = require('./dienstService')
+
+const app = express()
+app.use(express.json({ limit: '10mb' }))
+
+app.post('/webhook', async (req, res) => {
+  try {
+    await handleWebhook(req.body)
+    res.json({ success: true })
+  } catch (err) {
+    console.error('Webhook processing error:', err.message)
+    res.status(500).json({ success: false, error: err.message })
+  }
+})
+
+app.get('/health', (req, res) => {
+  res.json({ status: 'ok' })
+})
+
+const PORT = process.env.WEBHOOK_PORT || 3002
+
+loadDiensten()
+
+app.listen(PORT, () => {
+  console.log(`dienst-bot listening on port ${PORT}`)
+  console.log(`Allowed group: ${process.env.ALLOWED_GROUP}`)
+  console.log(`Bot name: ${process.env.BOT_NAME}`)
+})
diff --git a/src/messageHandler.js b/src/messageHandler.js
new file mode 100644
index 0000000..e947a3b
--- /dev/null
+++ b/src/messageHandler.js
@@ -0,0 +1,62 @@
+const { findDienst, getPngFilePaths } = require('./dienstService')
+const { sendTextMessage, sendImageMessage, notifyAdmin } = require('./whatsappApi')
+
+const BOT_NAME = (process.env.BOT_NAME || 'EdGpt').toLowerCase()
+const ALLOWED_GROUP = process.env.ALLOWED_GROUP
+
+function extractDienstnummer(body) {
+  const match = body.match(/\b(\d{4})\b/)
+  return match ? match[1] : null
+}
+
+function isBotMentioned(message) {
+  if (message._data?.mentionedJidList?.length > 0) {
+    return true
+  }
+  if (message.body && message.body.toLowerCase().includes(`@${BOT_NAME}`)) {
+    return true
+  }
+  return false
+}
+
+async function handleWebhook(payload) {
+  if (payload.dataType !== 'message') return
+  if (payload.sessionId !== process.env.WHATSAPP_SESSION) return
+
+  const message = payload.data?.message
+  if (!message) return
+  if (message.fromMe) return
+  if (message.from !== ALLOWED_GROUP) return
+  if (!isBotMentioned(message)) return
+
+  const dienstnummer = extractDienstnummer(message.body || '')
+  if (!dienstnummer) return
+
+  const author = message.author
+  if (!author) return
+
+  const dienst = findDienst(dienstnummer)
+  if (!dienst) {
+    await sendTextMessage(author, `Dienstnummer ${dienstnummer} niet gevonden.`)
+    return
+  }
+
+  const pngPaths = getPngFilePaths(dienst)
+  if (!pngPaths || pngPaths.length === 0) {
+    await sendTextMessage(author, `Geen pagina's gevonden voor dienst ${dienstnummer}.`)
+    return
+  }
+
+  for (const pngPath of pngPaths) {
+    const filename = pngPath.split('/').pop()
+    try {
+      await sendImageMessage(author, pngPath, filename)
+    } catch (err) {
+      const errorMsg = `Fout bij verzenden ${filename} naar ${author}: ${err.message}`
+      console.error(errorMsg)
+      await notifyAdmin(errorMsg)
+    }
+  }
+}
+
+module.exports = { handleWebhook }
diff --git a/src/whatsappApi.js b/src/whatsappApi.js
new file mode 100644
index 0000000..d8299d3
--- /dev/null
+++ b/src/whatsappApi.js
@@ -0,0 +1,46 @@
+const axios = require('axios')
+const fs = require('fs')
+
+const API_BASE = process.env.WHATSAPP_API_ENDPOINT
+const SESSION = process.env.WHATSAPP_SESSION
+
+async function sendTextMessage(chatId, text) {
+  const url = `${API_BASE}/client/sendMessage/${SESSION}`
+  const response = await axios.post(url, {
+    chatId,
+    contentType: 'string',
+    content: text
+  })
+  return response.data
+}
+
+async function sendImageMessage(chatId, filePath, filename) {
+  const fileBuffer = fs.readFileSync(filePath)
+  const base64Data = fileBuffer.toString('base64')
+  const url = `${API_BASE}/client/sendMessage/${SESSION}`
+  const response = await axios.post(url, {
+    chatId,
+    contentType: 'MessageMedia',
+    content: {
+      mimetype: 'image/png',
+      data: base64Data,
+      filename: filename
+    }
+  })
+  return response.data
+}
+
+async function notifyAdmin(errorText) {
+  const adminNumber = process.env.ADMIN_NUMBER
+  if (!adminNumber) {
+    console.error('ADMIN_NUMBER not configured, skipping admin notification')
+    return
+  }
+  try {
+    await sendTextMessage(adminNumber, `[dienst-bot fout] ${errorText}`)
+  } catch (err) {
+    console.error('Failed to notify admin:', err.message)
+  }
+}
+
+module.exports = { sendTextMessage, sendImageMessage, notifyAdmin }