Documentation

Two references, one system: the IDML format, and Paged — the engine, editor, SDK, scripting layer, and plugins built around it.

In short this site documents two things that explain each other. IDML is the open, inspectable format an InDesign document takes when it travels as text. Paged is the open-source system that reads, renders, and edits IDML — a render engine, a browser editor, an SDK, a scripting layer, and plugins. The two references cross-link throughout: every format concept points to the Paged surface that reads or writes it, and every API points back to the format it acts on. Pick the door that matches your question.

Choose a reference

• IDML Referencethe format, from first principles: the package on disk, geometry and layout, stories and styles, tables, color, images, and how the renderer reads each part. Start here to understand IDML itself.
• Pagedthe platform: the render engine and its WebGPU SDK, the paged.* scripting layer (with a live playground), the plugin SDK, the REST API, and the live capability state. Start here to build with Paged.

How both halves work

Every page declares one reader tier (🟢 beginner / 🟡 intermediate / 🔴 pro) and one job (tutorial, how-to, reference, or explanation), and carries a difficulty label. Both references are living: their support badges, capability matrices, API catalogs, and cross-links are generated from the system's own artifacts — the capability registry, the engine catalog, the manifest schema — so they grow with the code instead of going stale. Examples are real files validated against the actual renderer in CI.

Frequently asked questions

What is the difference between IDML and Paged? IDML is the file format; Paged is the software that reads, renders, and edits that format. The IDML Reference explains the document on disk. The Paged reference documents the engine, SDK, scripting layer, and plugins that act on it.

Where should I start? If your question is "what does this file contain / how is this document structured?", start with the IDML Reference. If your question is "how do I render, script, or extend documents?", start with Paged.

Is this the official IDML specification? No. It is an independent, community-minded reference written for humans from first principles. Where a strictly normative answer matters, we say so and point to the authoritative specification; element and attribute names are simple facts and are used freely.