Document Watermarking
Stamp a draft, confidential, or recipient mark onto documents as they are downloaded.
What it adds
A server-side watermarking stage applied to generated and stored documents on their way to a reader.
What your agent is told to do
5
What your agent is told to do
5-
1
Apply the mark on the server as the file is generated or served. A watermark drawn in the browser or laid over a preview is gone the moment somebody requests the raw file, which defeats the entire point.
-
2
Extend the app's existing PDF Export path rather than adding a second document pipeline. The watermark is a stage in the export, not a separate feature with its own renderer and its own fonts.
-
3
Make the mark legible without obscuring the content: a diagonal or footer mark at reduced opacity, sized against the page rather than a fixed number of points.
-
4
Support a recipient-identifying mark for documents that need leak tracing, carrying the reader's name or account and the time the copy was served.
-
5
Keep the clean original and the watermarked copy at separate storage paths with separate access rules, and never let a request for one return the other.
Edge cases it handles
8
Edge cases it handles
8- A mark drawn in the viewer is not a watermark. If the client composites it, the reader can request the underlying file directly and get a clean copy.
- A mark heavy enough to be unmissable is usually heavy enough to make small print unreadable. Tune opacity and size so the document is still usable at normal reading zoom.
- One file can hold pages of different sizes and rotations. Position and rotate the mark from each page's own box, or landscape and rotated pages get a mark running off the edge.
- When the mark identifies a recipient, the marked copy becomes personal data in its own right. Decide how long those copies are kept and who besides the recipient may read them back.
- Clean and watermarked copies must not share a cache key or a predictable filename. A shared key will eventually serve the unmarked file to someone entitled only to the marked one.
- Regenerating the same document for the same recipient must produce the same mark, or a leaked copy cannot be traced back to a single download.
- A document whose pages are scanned images needs the mark composited into the image layer. A text layer added over a flat scan may never render at all.
- Exporting an already-watermarked document through the same path must not stamp it twice.
Definition of done
8
Definition of done
8- Every document served through the export path carries the configured mark.
- The mark is applied server-side and is present in the raw downloaded file.
- Pages of differing size and rotation each carry a correctly placed mark.
- Body text stays readable at normal zoom with the mark applied.
- Recipient-marked copies record who they were issued to and when.
- Clean originals are stored apart from marked copies and are unreachable by a reader entitled only to the marked one.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
PDF Converter
PDF Converter
Let people turn the files they upload into PDFs, and PDFs back into editable formats.
What it does
A conversion service that accepts an uploaded document and returns it in a requested format, with progress and a downloadable result.
How it works
- 1 Start from the app's existing upload path rather than adding a second one. If File Upload, Upload Malware Scanning, or Secure File Downloads already exist, the converter consumes what upload produces and hands its output to the existing download route, so permissions and scanning are inherited rather than reimplemented.
- 2 Decide the conversion pairs you will actually support and list them in the interface. A short honest list of office documents, images, and PDF to text beats a control that offers every combination and fails on most of them.
- 3 Enforce file size, page count, and accepted types on the server before any conversion starts. A limit checked after the file has been parsed has already cost you the memory and the CPU you were trying to protect.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/pdf-converter
Fillable PDF Forms
Fillable PDF Forms
Let people fill in a PDF form on screen and download the completed copy.
What it does
An on-screen fill layer over a PDF form that writes the entered values back into a downloadable file.
How it works
- 1 Render the document and place editable inputs over its real form fields, so the user types on the page they recognise rather than into a separate form beside it.
- 2 Extend the app's existing PDF Export and document viewing paths rather than introducing a second renderer. Two renderers will disagree about fonts and page size, and the user will see the difference between screen and download.
- 3 Save progress as the user types using the app's existing Autosave, and restore the partly filled form on return.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/fillable-pdf-forms
Document Scanner
Document Scanner
Turn a phone photo of a paper document into a straight, readable, multi-page file.
What it does
A camera capture flow that detects page edges, corrects perspective, and assembles the shots into one document.
How it works
- 1 Lead with the capture screen: live edge detection, a shutter, and a running strip of the pages already taken. Somebody should be able to shoot five pages without leaving the camera.
- 2 Correct perspective and crop to the detected page before saving, then apply a contrast pass so a grey photo of a page reads as black text on white.
- 3 Give the user a review step where pages can be reordered, retaken, or deleted before anything is committed.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/document-scanner
How it works
-
1
Copy the link
Grab the Markdown instruction URL for this feature.
-
2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
-
3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.