A Zendesk ticket PDF app with no server behind it

In April 2026 Zendesk announced that several of its own free apps would stop working on 21 October 2026, including Print Ticket History and Attachment Manager. For printing, Zendesk points to the print option in the Agent Workspace, used together with its Incremental Exports API to build a PDF yourself. For anything more tailored, it suggests rebuilding the app in App Builder or upgrading the plan.

That leaves a small, common task without a simple tool. A customer, a manager or an auditor wants a readable copy of a conversation, with the custom fields and, sometimes, the internal notes. And in a ticket with dozens of replies, finding every file someone attached means scrolling through all of them.

• Printing from a locked-down frame. Zendesk runs sidebar apps in a sandboxed frame that doesn't allow dialogs, so the app can't open the print dialog itself. It writes a self-contained, printable document into a new window and prints from there. If the browser blocks the pop-up, the sidebar says so and explains how to allow it.
• Getting the whole ticket. Long tickets don't fit in one API call. The app follows Zendesk's cursor pagination for comments, 100 at a time with a hard cap on pages. It loads the ticket field definitions, so custom fields print their labels instead of raw values. Comment authors it doesn't know yet are fetched in batches of 100.
• Safe HTML in a new page. Zendesk already cleans comment HTML, but the app writes it into a fresh document. So it strips scripts, frames, forms and event handlers again before printing, and escapes every other value it shows.
• Private images. Pasted images are private files, and the print window often can't load them. Instead of a silent blank space, every image gets a visible caption with its file name, so the printout still says what was there.
• No "download all" button. We built a zip download and tested it in a real Zendesk account. Zendesk keeps attachments private and doesn't let apps fetch the files, so it could not work. We removed it rather than ship a button that fails, and kept per-file links that open with the agent's own login, with a tip for opening several at once.
• A blank panel on the first real install. Zendesk serves app files with a content type it guesses from their contents. Our separate script and style files arrived as generic binary data and never ran. Once they were inlined, raw control bytes in the code made Zendesk treat the page itself as binary, so the browser downloaded it instead of showing it. The build now puts the script and styles inside one HTML page, escapes every control and non-ASCII character, and fails if any remain.