here’s the backend + hook so your Generate Template button actually spits out a PPTX file download.

1) Install deps

On Replit backend:

npm i pptxgenjs express

2) Add API route — /api/ppt/build-template

server/api/ppt/build-template.ts

import { Router } from "express";
import PPTXGenJS from "pptxgenjs";

const router = Router();

router.post("/", async (req, res) => {
  try {
    const { size, brand, selections } = req.body;

    const pptx = new PPTXGenJS();

    // Size
    if (size === "4x3") pptx.layout = "LAYOUT_4x3";
    else pptx.layout = "LAYOUT_16x9";

    // Title Slide
    const masterTitle = {
      title: "Master Title",
      objects: [
        { rect: { x: 0, y: 0, w: "100%", h: "100%", fill: { color: brand.accents[0] || "363636" } } },
        { text: { text: brand.name || "Your Company", options: { x: 1, y: 2, fontSize: 36, color: "FFFFFF", fontFace: brand.fonts.heading } } },
      ],
    };
    pptx.defineSlideMaster(masterTitle);

    // Section Divider
    pptx.defineSlideMaster({
      title: "Section Divider",
      objects: [
        { rect: { x: 0, y: 0, w: "100%", h: "100%", fill: { color: brand.accents[1] || "4F81BD" } } },
        { text: { text: "Section Title", options: { x: 1, y: 2, fontSize: 28, color: "FFFFFF", fontFace: brand.fonts.heading } } },
      ],
    });

    // Body Layouts (simple placeholder content)
    selections.layouts.forEach((layout: string) => {
      const slide = pptx.addSlide();
      slide.addText(layout, { x: 1, y: 0.5, fontSize: 20, fontFace: brand.fonts.heading });
      slide.addText("Content area", { x: 1, y: 1.5, fontSize: 16, fontFace: brand.fonts.body, color: brand.accents[2] || "333333" });
    });

    // Infographics (basic placeholders)
    selections.infographics.forEach((inf: string) => {
      const slide = pptx.addSlide();
      slide.addText(`Infographic: ${inf}`, { x: 1, y: 0.5, fontSize: 20, fontFace: brand.fonts.heading });
      // Placeholder rectangles for sections
      const sections = parseInt(inf.match(/\d+/)?.[0] || "2", 10);
      const w = 9.0 / sections;
      for (let i = 0; i < sections; i++) {
        slide.addShape(pptx.ShapeType.rect, {
          x: 0.5 + i * (w + 0.1),
          y: 1.5,
          w: w,
          h: 2.0,
          fill: { color: brand.accents[(i % brand.accents.length) || 0] },
        });
      }
    });

    // Export
    const buf = await pptx.write("nodebuffer");
    res.setHeader("Content-Disposition", 'attachment; filename="ibrandbiz-template.pptx"');
    res.setHeader("Content-Type", "application/vnd.openxmlformats-officedocument.presentationml.presentation");
    res.send(buf);
  } catch (e: any) {
    console.error("PPT build error", e);
    res.status(500).json({ error: "Failed to build PPTX" });
  }
});

export default router;


Hook this route into your Express server index:

import pptRoute from "./api/ppt/build-template";
app.use("/api/ppt/build-template", pptRoute);

3) Update frontend generateTemplate

In PresentationTemplate.tsx replace the stub:

async function generateTemplate() {
  const res = await fetch("/api/ppt/build-template", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(buildConfig()),
  });
  if (!res.ok) {
    const j = await res.json().catch(() => ({}));
    alert(j.error || "Build failed");
    return;
  }
  // Get blob and force download
  const blob = await res.blob();
  const url = window.URL.createObjectURL(blob);
  const a = document.createElement("a");
  a.href = url;
  a.download = "ibrandbiz-template.pptx";
  a.click();
  window.URL.revokeObjectURL(url);
}

4) What you get now

Frontend: user sets size, logo, fonts, colors, layouts, infographics → clicks Generate Template.

Backend: builds a real PPTX with:

Title/section masters

Layout slides (placeholders)

Infographic placeholders (colored rectangles by section count)

File downloads immediately.