Aipen for ChatGPT

Turn any ChatGPT answer into hyper realistic handwritten, print-ready notes without leaving the chat.

Aipen for ChatGPT is an OpenAI Apps SDK application built on MCP. Ask ChatGPT for notes, a worked solution, a letter, or a report, and Aipen renders it as a paginated A4 handwritten document with an inline preview and a downloadable vector PDF that stays crisp when printed or zoomed in.

This repository intentionally contains only the standalone MCP server and its inline ChatGPT component. The proprietary Aipen editor and render engine remain separate. Its humanization layer can select from up to 20 glyph variations per character, which helps long documents avoid a mechanically repeated look.

The images above are real Aipen renders: handwritten layout, ruled A4 paper, humanized letterforms, rendered mathematics, and an accurate hand-drawn graph.

Judge Quick Start: No Rebuild Needed

The live MCP endpoint is:

https://aipen-mcp-511200400258.us-central1.run.app/mcp

To test it in ChatGPT Developer Mode:

1. Open ChatGPT and enable Developer Mode.

2. Create or add a custom app/connector.

3. Paste the live endpoint above as the MCP server URL.

4. Start a new chat and ask, for example:

   Create two pages of handwritten calculus revision notes with worked examples.
   

5. ChatGPT calls make_handwriting. Wait for the inline Aipen card, preview the handwritten page, change style options if desired, and select Download PDF.

The demo accepts up to 6,500 characters, renders up to five pages per request, and allows 40 renders per IP per hour.

Demo Video

Watch the full 4K trailer and product walkthrough on YouTube:

https://www.youtube.com/watch?v=SdR5WnF-BUk

Architecture

ChatGPT
  -> MCP server on Cloud Run
  -> Playwright / headless Chromium
  -> private Aipen render engine
  -> per-page JPEG previews + vector PDF
  -> private Google Cloud Storage artifacts
  -> inline Aipen card in ChatGPT

Under the hood, the MCP receives structured note text and appearance options, opens Aipen in a headless browser, waits for Aipen to finish rendering, captures each Paged.js page as a modest JPEG preview, and produces the final PDF with Chromium page.pdf(). The PDF is not assembled from preview images.

Artifacts are placed in a private Google Cloud Storage bucket and served through the MCP's /assets/:id proxy. The app enforces a one-hour artifact expiry; bucket lifecycle cleanup removes leftover objects later.

Features

• Inline ChatGPT UI with A4 paper preview and PDF download
• True vector PDF output from Chromium: text and paths stay crisp at any zoom
• Per-page JPEG thumbnails for fast previews
• Accurate hand-drawn graphs and charts when explicitly requested
• Four Aipen handwriting styles: Classic, Clean, Script, Casual
• Ink, paper, and humanization controls
• Markdown and LaTex-style math support through the Aipen render engine
• Hard demo protections: 6,500 characters, five pages, 40 renders/IP/hour
• Private, temporary artifact storage with no browser-exposed cloud credentials

Study Materials

Aipen turns AI explanations into printable, annotatable study materials. Learners can review, highlight, and work through them by hand. It does not claim that viewing generated handwriting has the same learning effect as personally writing notes by hand.

Language Support

Native handwriting currently supports English and languages using the standard English alphabet, including Afrikaans, Albanian, Catalan, Croatian, Czech, Danish, Dutch, Estonian, Finnish, French, German, Icelandic, Irish, Italian, Latvian, Lithuanian, Norwegian, Polish, Portuguese, Romanian, Slovak, Slovenian, Spanish, Swedish, Turkish, and Welsh. More languages are planned.

Future Possibilities

Aipen is designed to grow beyond study notes. Planned directions include:

• Letter and email automation with handwritten, print-ready output
• Branded stationery, business documents, and personalized card templates
• Real-estate packs, lab reports, finance notes, and subject-specific layouts

Local Development

Requirements:

• Node.js 20+
• A Chromium-capable machine
• An Aipen render URL
• Google Cloud Application Default Credentials for local artifact storage

npm ci
npx playwright install chromium
gcloud auth application-default login

$env:AIPEN_RENDER_BASE = "https://aipen-render-511200400258.us-central1.run.app"
$env:GCS_ARTIFACT_BUCKET = "aipen-mcp-artifacts"
$env:PORT = "3001"

npm run check
npm run build
node dist/index.js

For local Aipen engine development, replace AIPEN_RENDER_BASE with your local render server, such as http://localhost:3000.

The local MCP endpoint is http://localhost:3001/mcp.

Deployment Checklist

• Confirm PUBLIC_BASE_URL is set to the canonical public Cloud Run URL.
• Confirm production traffic targets only the intended revision.
• After any tagged test revision, remove its tag and verify the traffic output has no tag or tagged url entries before considering the deployment complete.

Environment Variables

Variable	Required	Purpose
PORT	No	HTTP port. Defaults to 3000.
AIPEN_RENDER_BASE	Yes in production	Base URL for the Aipen render engine.
GCS_ARTIFACT_BUCKET	No	Private artifact bucket. Defaults to aipen-mcp-artifacts.
PUBLIC_BASE_URL	No	Overrides the externally visible MCP origin for artifact URLs.
MAX_ANONYMOUS_RENDERS_PER_HOUR	No	Per-IP demo allowance. Defaults to 40.

On Cloud Run, the attached service account receives bucket-only roles/storage.objectAdmin; no JSON key, API key, or Secret Manager value is required for artifact access.

Built With Codex and GPT-5.6

OpenAI Codex and GPT-5.6 assisted with the MCP server, Apps SDK integration, Playwright render pipeline, inline ChatGPT UI, Cloud Run containerization, Google Cloud Storage artifact persistence, tests, and documentation. Aipen provides the independent handwriting render engine, page design, fonts, math rendering, paper styles, and glyph humanization.

License

MIT. See LICENSE.