slidegen

A local-first AI slide generator. Claude Code plans the deck, Nano Banana renders the imagery, real PowerPoint text gets overlaid by the renderer, and you walk away with a .pptx (or .pdf) you can drop into Google Slides, Keynote, or PowerPoint.

Runs entirely on your machine. Your claude CLI subscription handles the planning; you bring a Google API key for image generation. No server to deploy, no data leaves your laptop except the API calls.

What it does

• Plans the deck — Claude picks layouts, writes content, generates speaker notes, picks an icon and a section eyebrow per slide
• Themes — 7 curated presets (Editorial Warm, Tech Noir, Cool Mint, Bold Magazine, Hand-drawn, Corporate, Auto) or paste a brand hex color
• 12 layouts — title-hero, content-image-right/left, two-column, big-stat, full-bleed-quote, section-divider, comparison, agenda, bar-chart, pie-chart, closing-cta
• Generates the imagery — Nano Banana (Gemini 2.5 Flash Image) renders one image per slide where it makes sense
• Reviews the composed slide — Claude screenshots the rendered slide and re-prompts up to 2× if it can be improved (text-in-image, off-style, low contrast)
• Native PPTX charts — bar and pie charts ship as real editable PowerPoint charts, not images
• Refines via chat — type "make slide 3 punchier" or "add a pricing slide" and Claude updates the deck
• Exports — .pptx (with editable text frames) or .pdf (full-fidelity)
• Aspects — 16:9, 4:3, 9:16 (Stories/Reels), 1:1 (square)
• Saves decks to localStorage so you can come back later

Setup

git clone https://github.com/ayushg8/slidegen.git
cd slidegen
pnpm install
cp .env.local.example .env.local
# edit .env.local and paste your GOOGLE_API_KEY (get one at https://aistudio.google.com/apikey)

You also need:

• Node 20+ (Next.js 16 minimum)
• pnpm
• Claude Code CLI authed on your machine — which claude should resolve. The app shells out to your local claude binary, which uses your existing CC subscription. No ANTHROPIC_API_KEY is read by the app.

Run

pnpm dev

Open http://localhost:3000. Pick a template + theme, write a topic, click Plan deck, then Generate all. Export with .pptx or .pdf.

Cost model

Operation	Where it bills	Typical cost
Plan / Refine / Review (Claude)	Your Claude Code subscription seat	Covered by plan, $0 metered
Image generation (Nano Banana)	Your Google API key	~$0.039 per image (1290 output tokens × $30/1M)
Text-only slides (comparison, agenda, charts)	—	$0
.pptx / .pdf export	—	$0 (local)

A typical 10-slide deck has 5–6 imaged slides → ~$0.20–$0.25 per deck. The UI shows a live cost ticker.

How it works

┌──────────────────────────────────────────────────────────────────┐
│ Browser (localhost:3000)                                         │
│  ↳ Pick template/theme, write topic                              │
│  ↳ Live SlidePreview mirrors the PPTX renderer 1:1               │
└────────────┬─────────────────────────────────────────────────────┘
             │
             ▼
┌──────────────────────────────────────────────────────────────────┐
│ Next.js (App Router) routes                                      │
│  /api/plan        → streams NDJSON status + final deck JSON      │
│  /api/refine      → chat-style edit                              │
│  /api/generate    → Nano Banana → PNG data URL                   │
│  /api/generate-variations → 3 images in parallel                 │
│  /api/render-slide→ puppeteer → composed-slide PNG screenshot    │
│  /api/review      → screenshot the slide, send to Claude         │
│  /api/deck-review → Claude reviews the whole deck end-to-end     │
│  /api/export      → pptxgenjs → .pptx                            │
│  /api/render-pdf  → puppeteer multi-page → .pdf                  │
└────────┬─────────────────────────────────┬───────────────────────┘
         │                                 │
         ▼                                 ▼
 ┌──────────────────────┐     ┌─────────────────────────────┐
 │ scripts/claude-      │     │ Google Generative AI SDK    │
 │   server.mjs         │     │ (Nano Banana / Flash Image) │
 │  loopback only       │     └─────────────────────────────┘
 │  token-authed        │
 │  spawns `claude` CLI │
 │  per request         │
 └──────────────────────┘

The Claude server is modeled on gstack browse's pattern: persistent loopback HTTP service, token in .slidegen/claude-server.json, auto-respawn on first request, idle-shuts-down at 30 min.

Project layout

slidegen/
  bin/slidegen-claude              # shell control: status / start / stop / plan
  scripts/claude-server.mjs        # local HTTP service that owns the claude CLI
  src/
    app/
      page.tsx                     # the whole UI
      api/{plan,refine,generate,...}/route.ts
    components/
      slides/SlidePreview.tsx      # live HTML preview, mirrors the PPTX
    lib/
      claude-client.ts             # NDJSON streaming client to claude-server
      gemini.ts                    # Nano Banana wrapper
      slide-html.ts                # server-side HTML renderer (12 layouts)
      pptx.ts                      # pptxgenjs builder (12 layouts, charts, chrome)
      pdf.ts                       # multi-page PDF via puppeteer
      screenshot.ts                # singleton puppeteer browser
      icon.ts                      # lucide kebab-case → SVG
      types.ts                     # Slide / Deck / Theme / preset definitions
      pricing.ts                   # cost calc
  .env.local.example               # GOOGLE_API_KEY=

Roadmap / known gaps

• Real-time SSE for image generation status (currently per-slide polling)
• Custom logo upload (currently brand color only)
• "Push to Google Slides" via OAuth (currently .pptx upload)
• More chart types (line, scatter, doughnut)
• Web access for Claude planning (currently subscription-mode CLI = no web search)

PRs welcome.

License

MIT — see LICENSE.