Services and providers
Oncewhisp · 2026-10-01.3Hosting — Hetzner
Hetzner Online GmbH hosts the API, database and delivery services, processing account data, connections, metadata, pending ciphertext and profile photos. Oncewhisp region: Hetzner Online GmbH, Germany. The production server and encrypted backup storage are located in Falkenstein.. Encrypted backups are stored separately from the application server.
Email — Brevo
Brevo / Sendinblue SAS sends account emails and receives email addresses, language, email content and delivery data, including necessary links or codes. Account emails are not end-to-end encrypted chat messages. Retention: Brevo transactional logs are retained for one month; message previews are disabled and tracking data is anonymized asynchronously for all senders. Provider deletion processing can take up to 24 additional hours. Support correspondence in the contact mailbox is retained while needed to resolve the request and then deleted, except information needed for a documented legal retention duty or claim. Copies held by recipients follow their own mailbox settings..
Notifications — Expo, Apple and Google
The integration uses Expo Push Service and APNs/FCM when enabled. Device tokens, the sender’s nickname with code and delivery metadata are transmitted; chat text, photos and audio are not included. You can revoke permission on your phone. These providers may process notification data outside the EEA, including the United States; see the transfer information in the privacy policy.
Domain and development
Bitbucket / Atlassian is used to manage source code and deployments. We do not intentionally send chat content to repositories. Our support mailbox receives the information you choose to send. Mailbox provider and any forwarding: united-domains GmbH (email hosting under a data processing agreement). Contact correspondence is separate from end-to-end encrypted chats..
Payments and analytics
The current version of Oncewhisp has no payments, advertising or behavioral analytics. Stripe is used for our business subscription to Adressgeber, not to process payments from users of this app.
Postal correspondence — Adressgeber
TC Medien GmbH, trading as Adressgeber, receives correspondence at our public address and may open and scan it under the postal authorization and processing agreement. Scans are sent by email without a guarantee of end-to-end encryption and are normally retained for 30 days after sending, subject to contractual or legal exceptions. Originals are stored, forwarded or destroyed under the contract. This concerns postal correspondence only: this service does not give Adressgeber access to your chat messages.
Contact email — united-domains
Our contact, support, privacy and safety addresses use mailboxes hosted by united-domains GmbH under a data processing agreement. The provider processes sender addresses, email contents, attachments and delivery metadata. This correspondence is separate from encrypted chats.