Where your data lives, what zero-knowledge means
Your journal content — opponent observations, match reflections, training entries, events, AI outputs, behavioral history, photos, and videos — lives on your connected storage (Google Drive, iCloud, or Dropbox). We store authentication, subscription state, usage counters, and a lightweight shell of IDs, dates, and sport tags. Your notes are not stored on our servers.
There are two layers. We have no stored copy of your journal in either mode. Optional end-to-end encryption (E2EE) also hides your encrypted text content from the storage provider by encrypting it on your device before upload.
Use the recovery code you were shown when you enabled E2EE. It is shown only once. If you lose both the password and the recovery code, neither we nor your storage provider can recover your encrypted content.
If you don't connect a storage provider, OpponentBook runs local-only: everything stays in this device's browser/app storage and nothing syncs to the cloud or to your other devices. You can journal fully offline. Connect Google Drive, Dropbox, or iCloud from Settings → Storage whenever you want cross-device sync — your existing local data uploads on the first sync.
Not yet. E2EE encrypts your journal records, including notes, matches, training, events, AI outputs, and behavioral history. Photos and videos remain ordinary files on your storage provider and are protected by that provider's standard security. If your threat model requires provider-blind media, do not upload media yet.
The questions we hear most, answered without hedging. If you don't find what you need, email support@opponentbook.com.
The whole journal is free, forever, on your own storage.
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