refern. VS DynamicDocumentAPI

refern.'s answer

I'm an artist, and too often I was frustrated: I couldn't find the right pictures, I struggled to organize and keep track of my reference images, and I was juggling too many apps when all I wanted to do was draw. I wanted one tool that could do it all, with every component well integrated. So I made refern.

DynamicDocumentAPI's answer:

Almost every product eventually needs to produce documents, and most teams end up building their own rendering stack: a headless browser, fonts, page breaks, storage and retries. It works until an invoice splits a table row or a certificate shows the wrong date, and then it becomes a support ticket. We built Dynamic Document API to be that layer for them: templates, rendering and delivery as one service, hosted in Europe, treating pagination, fonts and formatting as engineering problems rather than edge cases. When e-invoicing became mandatory for B2B in Germany, we added validated XRechnung and ZUGFeRD output, and with AI agents producing more paperwork, an MCP server followed.

refern.'s answer

The flow of collecting references for art usually goes like this:

find references and inspiration online -> save and organize those images -> use them on their own or in a moodboard -> reuse them for the next project or share them with others

Normally that means a different app for each step. refern does all of it in one place, with every part built to work together.

DynamicDocumentAPI's answer:

It covers the whole path from data to finished document in one API: you design a template in a visual or HTML editor (or send raw HTML, CSS or Markdown), send JSON, and get a PDF or image back. The same service also creates e-invoices (XRechnung, EN 16931, Factur-X / ZUGFeRD) that are validated against the official rules before they are returned, and can embed them in the PDF. Rendering is deterministic: the same template and data always give the same document, laid out by a headless browser, with no AI model generating content. Everything runs in the EU (Germany). It also ships an MCP server, so AI agents like Claude and ChatGPT can render documents directly.

refern.'s answer

Most tools solve only one part of the reference workflow, so artists end up juggling several. refern combines them in one app: Eagle-style organization and search, a PureRef-style infinite canvas, and an Obsidian-style graph of how your references connect. It never copies your files, so it doesn't double your disk usage. It runs on Windows, macOS, and Linux, works fully offline, and is a $30 one-time purchase with no subscription. Built in Rust, it stays fast even on libraries with hundreds of thousands of images.

DynamicDocumentAPI's answer:

Most document APIs do one thing: convert HTML to PDF, or fill templates. Dynamic Document API does both, adds image templates, PDF merging and validated e-invoices, and offers them through a REST API, SDKs for Node and Python, Zapier, Make, n8n and an MCP server for AI agents. Data is processed and stored in the EU only, files come back as signed links that expire, and storing nothing at all is a supported option. Pricing is predictable: one published credit table, the same core features on every paid plan and a spend cap you control. We also publish a render-time benchmark with its method and raw data, so you can check our speed instead of trusting a claim. The free plan includes 50 renders a month without a credit card.

refern.'s answer

Individual artists and creative professionals: illustrators, concept artists, digital painters, designers, and photographers. They collect and organize large libraries of visual references, build moodboards, and study from reference. refern is built for solo creators rather than teams, spanning hobbyists and students through working professionals.

DynamicDocumentAPI's answer:

Developers and product teams whose software has to send documents: invoices after a payment, certificates after a course, reports, labels and statements. Typical users are SaaS companies, marketplaces, e-commerce and learning platforms. A second group are businesses in Germany and the EU that need compliant e-invoices (XRechnung, ZUGFeRD) for the German B2B e-invoicing mandate and public-sector buyers. No-code builders use it through Zapier, Make and n8n, and teams building AI agents use the MCP server.

refern.'s answer

refern is a Tauri v2 desktop app with a Rust backend and a React 19 (with React Compiler) plus TypeScript frontend. Data is stored locally in SQLite (rusqlite) with FTS5 full-text search. The interface uses Tailwind CSS, Zustand, and TanStack Query, with motion/react for animation. The infinite canvas and graph view are built on react-three-fiber and three.js. Thumbnailing, perceptual hashing, and color and visual similarity run in Rust with rayon and SIMD.

DynamicDocumentAPI's answer:

Rendering runs in Rust workers that drive headless Chromium over the DevTools protocol, with MiniJinja for templates. The API and control plane are built with Django and Django REST Framework, with Celery, PostgreSQL, Valkey and NATS JetStream for queues and events, and S3-compatible object storage for files. PDF/A output is checked with veraPDF and e-invoices with the official KoSIT validator. The dashboard and website are built with Next.js. Everything runs on Kubernetes in data centres in Germany.

DynamicDocumentAPI's answer:

Dynamic Document API is a young product. Our users are mostly developers and small SaaS teams, and we don't name customers without their permission.