KeePassDX is an Android password manager that opens, edits, and stores encrypted credential databases using the open KeePass 2.x file format. It keeps all password data stored locally on the device without requiring cloud sync or internet access, and supports multiple symmetric-key encryption algorithms including AES, Twofish, and ChaCha20 with Argon2 key derivation.
The app unlocks the credential database by delegating authentication to the platform's biometric API, allowing users to bypass the master password entry using fingerprint or face recognition. It generates one-time passwords locally by implementing the HMAC-based and time-based OTP algorithms from RFC 4226 and RFC 6238 for two-factor authentication, and persists WebAuthn credential private keys in the encrypted database using the CTAP2 credential ID format for local passkey-based sign-in.
KeePassDX injects credentials into other apps by running as an Android accessibility service that monitors UI state and programmatically fills text fields, and also provides a dedicated Android input method editor that displays credential fields and inserts text directly into the focused input element. The application structures credentials in a hierarchical tree of groups and subgroups, maintains a change history for each entry, and supports creating and editing encrypted databases with multiple cipher options.
