idmlkit

The AI-native toolkit for Adobe InDesign files (IDML) — parse, summarize, and safely write back. No InDesign required.

Works directly on .idml files (InDesign's open, XML-based interchange format), so it runs anywhere Node.js runs — servers, CI pipelines, Linux — with nothing from Adobe installed.

Design philosophy: the AI never touches the XML

LLMs are great at deciding what should change in a document, and terrible at hand-editing thousands of lines of layout XML without breaking it. So idmlkit splits the work:

• Deterministic code parses the package and produces a compact, LLM-friendly summary (pages, frames, stories as indexed text runs, image links, styles).
• Write-back is surgical: replacing a text run or relinking an image rewrites only that one element via targeted string surgery. Everything else — geometry, styles, the XML formatting itself — is preserved byte-for-byte (enforced by tests).

Install

npm install idmlkit

Library

import { IdmlDocument, summarizeDocument, setStoryRunText } from "idmlkit";

const doc = await IdmlDocument.open("catalog.idml");
console.log(summarizeDocument(doc));      // LLM-friendly JSON
setStoryRunText(doc, "u123", 0, "New headline");
await doc.save("catalog-updated.idml");

CLI

$ idmlkit summary catalog.idml
Pages: 1  Spreads: 1
Story u123 (11 words, 2 runs): Spring Catalog 2026 Fresh arrivals for the new season…
Image link u202: file:/images/hero.jpg
Paragraph styles: $ID/NormalParagraphStyle, Headline, Body

$ idmlkit set-text catalog.idml u123 0 "Summer Sale 2026" -o out.idml
$ idmlkit relink out.idml u202 "file:/images/summer.jpg"

Use cases

• Database publishing: fill a designed template with product data without opening InDesign once.
• Localization: extract every text run with its styles, translate, write back safely.
• Agent workflows: pair with idml-mcp to let Claude or any MCP-capable agent read and edit layouts.

License

MIT. Not affiliated with or endorsed by Adobe. "Adobe" and "InDesign" are trademarks of Adobe Inc., used here only to describe compatibility.