Lagrange 2.0.0

Release date: 2026-10-11

Lagrange 2.0.0 expands the Android client beyond BookOrbit with an initial Komga integration, provider-scoped state, and EPUB narration, reader, accessibility, offline, and security improvements.

Highlights

• Added Komga as a supported server provider alongside BookOrbit.
• Added provider-specific modules for authentication, catalog mapping, covers, downloads, reader preparation, and capability routing.
• Added Komga library browsing, book details, Series, supported Home shelves, authenticated covers, downloads, offline catalog reopening, and EPUB, PDF, and comic reading.
• Added Komga Basic Auth and server-hosted WebView sign-in, including configured OAuth2/OIDC providers.
• Added provider/profile session restoration when switching between BookOrbit and Komga.
• Added EPUB text-to-speech with sentence highlighting, local narration state, screen-lock playback, media-session controls, voice selection, speed and pitch controls, and selected-text narration.
• Added EPUB 3 publisher-provided read-along narration with synchronized highlighting and lock-screen controls.
• Added EPUB OLED black theme, reader navigation-bar controls, PDF color inversion, unread cover markers, format-specific tap-zone tutorial persistence, and Preview-to-Read progress reconciliation.
• Improved audiobook playback controls, progress presentation, audio-focus behavior, multipart playback, and provider-switch rebinding.
• Improved offline downloads, cached catalogs, local-file fallback, and grouped physical-file handling.

Komga support

Komga support is intentionally narrower than BookOrbit. The supported surface includes server setup, Basic Auth, server-hosted WebView sign-in, library browsing, book details, Series, supported catalog filtering and sorting, authenticated EPUB/PDF/comic access, background downloads, Local Books, offline reopening, and provider-scoped server switching.

Komga does not provide every BookOrbit capability. Authors, Smart Scopes, achievements, statistics, annotations, audiobook workflows, server reading-session history, and some progress/status operations remain unavailable or provider-specific. Unsupported actions are hidden or reported as unavailable rather than treated as successful no-ops.

The detailed Komga checklist and provider function matrix remain the source of validation detail and will receive follow-up updates after the release preparation step.

Security fixes

• Fixed authenticated catalog image requests so BookOrbit credentials are not sent to unintended image origins. Security advisory: GHSA-vr98-2hj5-h9wp.
• Bounded EPUB custom-font preparation to reduce memory-exhaustion risk from defective or malicious EPUB archives. Security advisory: GHSA-rmjp-8gm4-6j6w.

JBWortley is credited as the reporter for both advisories.

Known limitations accepted for 2.0.0

• EPUB resume and progress handling can retain a stale local position in niche multi-device or rapid-close race cases. Issues #274 and #276 remain open for post-release hardening.
• An intermittent BookOrbit single-file download crash remains unreproduced and tracked in #211.
• Native OIDC/AppAuth and Custom Tabs remain deferred until the required server redirect support is available.
• MOBI, AZW, AZW3, and FB2 remain unsupported.
• Google Play publication is prepared separately. GitHub remains the active distribution path for this release.

Distribution

• Normal combined APK: Lagrange-2.0.0.apk
• ARM alternative: Lagrange-2.0.0-arm.apk
• 32-bit x86 alternative: Lagrange-2.0.0-x86.apk
• 64-bit x86 alternative: Lagrange-2.0.0-x86_64.apk

If you are unsure which architecture to choose, download the plain combined APK.

Verification

• JVM unit tests: 875 passed, 0 failures, 0 errors, 0 skipped.
• Kotlin compilation passed for main, JVM tests, and Android tests.
• lintDebug passed.
• Debug, Android-test, and signed release APK assembly passed locally.
• Current-device validation remains separate from automated verification and must be recorded from the final release artifact.

Upgrade notes

No migration action is currently identified for the 2.0.0 provider-module changes. Existing BookOrbit profiles and local downloads should be retained. Komga users can add a Komga profile from the server-selection flow.