expat.fyi is a one-person product. Here is exactly what happens to your data: no legalese, no corporate padding.
Your letter
When you upload a letter, it is sent to Anthropic's API, which generates the plain English explanation. We don't store your letter ourselves: it is not saved to any database of ours. Our site runs on Vercel, so the upload passes through Vercel on its way to Anthropic.
Session data
We use Upstash to store a session ID and the generated explanation for 24 hours, so we can show you your result after payment. The explanation can include details from your letter, such as the sender and any deadline. Once you pay, a marker with that session ID is also kept for 24 hours. All of this is deleted automatically when the time is up.
Rate limits
To limit abuse, we count how many times each IP address uses the letter upload, the free Letter Check and the chat assistant per day. Each count is stored in Upstash under a key that contains your IP address, and is deleted automatically after 2 days.
Payment
Payment is handled by Lemon Squeezy, who act as the Merchant of Record. We never see your card details. We pass Lemon Squeezy your session ID so we know which result to unlock. Lemon Squeezy's privacy policy applies to the payment step.
Your data is not for sale
We do not sell your data. We do not share it with advertisers. We pass it only to the services named on this page: Anthropic (AI processing of your letter to generate the explanation, plus the Letter Check and chat below), Vercel (hosting and analytics), Upstash (24-hour storage of the session ID and explanation, plus the rate-limit counts), Lemon Squeezy (payment), Brevo (our email list, only if you sign up) and Google (Gmail, only if you email us).
AI models
We use Claude (by Anthropic) to generate explanations. Anthropic does not use data sent through its commercial API to train its models, per its commercial terms. Anthropic says it deletes API inputs and outputs within 30 days, unless it must keep them longer to enforce its usage policy or by law. We do not train any AI model ourselves.
Letter Check and chat assistant
The free Letter Check sends the sender and subject line you type to Anthropic. The chat assistant sends your messages to Anthropic to generate a reply. We don't save either of these ourselves.
Email list
If you enter your email in one of our sign-up forms, such as the free guide on the homepage, your address is sent to Brevo, which holds our email list.
Analytics
Vercel hosts this site and provides Vercel Analytics, which we use to understand basic traffic patterns (page views, country). We set no tracking cookies ourselves.
Contact
Questions about this policy? Email us at expat.fyi.reach@gmail.com. If you email us, your email and any attachments are handled in our Gmail account (Google).