Trust
Subprocessors
The outside services that process data on XOsign's behalf — what each one does, and exactly what data it can see.
XOsign runs on a small, deliberate set of service providers. This page lists all of them. When the list changes, this page changes with it — last updated 2026-10-17.
Services that process customer data
| Service | What it does | What it can see |
|---|---|---|
| Supabase | Database, file storage, and sign-in | Everything you store in XOsign — documents, signatures, account data |
| Vercel | Runs the website and its server functions | All traffic to and from XOsign |
| Anthropic | Reading scanned pages that our main OCR service (Google Document AI) can't read. Also currently: checking drafts against your XOterms, drafting contracts and suggesting upgrades, capturing your brand style, suggesting template fills, and working out which party you are in a review. Also the backup for summaries, clause explanations, translation, signer-role detection, vault filing and Help Center answers when OpenAI is unavailable. Not used for XO chat or voice. | Page images of scanned documents, and the content of documents you run the features above on, per request |
| OpenAI | XO chat and voice (including speech-to-text and read-aloud), contract review (summaries, clause explanations, risks, suggested edits, gap analysis and comparisons), unlocking documents (reading and filing them), finding and placing signature fields, reading photos, scans and financial documents, filing and searching documents in XOfiles, translation, signer-role detection, and Help Center answers | The content of documents you run AI features on, and what you say or type to XO, per request |
| Stripe | Payments and subscriptions | Billing name and email. Card numbers never touch XOsign's systems |
| Resend | Sends email (signing invitations, completed copies, receipts) | Recipient names, email addresses, and document links or attachments |
| Telnyx | Sends text messages (signer verification codes), and sends and receives faxes | Phone numbers and the message text; for a fax, the fax numbers and the faxed document |
| Google Cloud (Document AI) | Reads scanned pages (OCR), and the cover page of a fax sent to XOsign's shared fax number | Page images, when you unlock a scanned document; the first page of a fax to the shared number |
| Fly.io | Renders documents to PDF | Document content during rendering |
| PostGrid | Prints and mails a document you send with Mail by USPS | The document you mail, and the recipient's name and mailing address |
Services that receive only minimal data
| Service | What it does | What it can see |
|---|---|---|
| FreeTSA | Independent trusted timestamps on completed documents | A document's SHA-256 fingerprint only — never its content |
| Esri (ArcGIS) | Property lookup | The address you type into the lookup |
| USPS | Certified-mail tracking | Tracking numbers only |
Analytics and advertising
These run only when they are switched on below, and then only with your permission in the cookie choices — never on a signing link, and inside your account only to report a completed purchase. See Cookies in our privacy policy.
- XOsign visitor countOff
Our own count of how many different browsers visit, and of sign-ups and purchases. Analytics cookies.
Sees: A random id in a cookie and the day of the visit. No account, name, email, IP address or page address.
- Google AnalyticsOff
Which pages are visited and how people move through the site. Analytics cookies.
Sees: Pages visited, the referring site, device and browser type, approximate location.
- Google AdsOff
Tells Google when one of our ads led to a sign-up or a purchase. Advertising cookies.
Sees: That a sign-up or purchase happened after an ad click, and the purchase amount.
- Meta (Facebook and Instagram)Off
Tells Meta when one of our ads led to a sign-up or a purchase. Advertising cookies.
Sees: Public pages visited; at sign-up or purchase, the email address hashed (scrambled one way), the browser's IP address and type, and the purchase amount.
- LinkedInOff
Tells LinkedIn when one of our ads led to a sign-up or a purchase. Advertising cookies.
Sees: Public pages visited, and that a sign-up or purchase happened.
Built but switched off: some integrations exist in the product and are currently disabled — online notarization and cloud-storage import. Before any of them starts handling customer data, it is turned on deliberately and added to the list above.
Questions? Write to security@xosign.ai.