How SimpleAddins is built
A high-level view of the architecture — enough for IT and security teams to understand where your document is handled and what does and doesn't leave your device.
The short version
Your document is processed on your device
Both add-ins read your document, find the fields or formatting, and write the results back entirely within your own copy of Microsoft Word. The document itself is not sent to us to be scanned, filled or colour-coded — this is Word document automation without cloud upload.
The add-ins do make network requests — for licensing, account and analytics — which is why Microsoft lists them as able to send data over the internet. That traffic never includes the contents of your documents. The distinction is set out in plain English on the Privacy Explained page.
The building blocks
Office.js task pane
Standard Microsoft add-in architecture. The add-in runs in a sandboxed pane beside the document and can only act on the document the user has open, when the user clicks a button.
Local document processing
Reading, field detection, filling and colour-coding all run in the browser engine hosting the pane, on the user's device. The document stays in Word throughout.
No document store
We operate no repository of customer documents. There is nothing on our side to breach, subpoena or misconfigure, because your files never arrive.
Microsoft AppSource distribution
Both add-ins are published through Microsoft AppSource and re-certified on each release, so you inherit Microsoft's review of the manifest and requested permissions.
Authentication & licensing
Pro features are unlocked against your account through a licensing service. Payment is handled by Stripe — card details are never held by us.
Least-privilege permissions
The add-ins request access only to the active document. They ask for no access to mailboxes, sites, directories or other files.
What is and isn't transmitted
A precise split rather than a reassuring slogan. The same breakdown, row by row, is on the For Organisations page.
Processed on your device
Reading the document · detecting formatting · finding placeholder fields · applying colour · filling fields · resolving conditional clauses · saving clips and profiles
Sent to our service providers
Licence and subscription checks · payment processing (Stripe) · account name and email · website analytics
Full detail in the plain-English privacy explanation and the privacy policy.
Need this for a security review?
If you're completing a supplier security questionnaire or need deployment detail for a rollout, get in touch and you'll speak to someone who works on the product.