BLACKBIRD

Open-source licences

Last updated 18 October 2026

Blackbird is built on open-source software, listed on this page. Each project is used under its own licence; follow a link for the full text and the copyright notice that goes with it.

In the Android app

  • AndroidX — core, appcompat, activity, fragment, lifecycle, constraintlayout, recyclerview, biometric, work, room, media3 — Apache License 2.0
  • Material Components for Android — Apache License 2.0
  • Kotlin and kotlinx.coroutines — Apache License 2.0
  • OkHttp — Apache License 2.0
  • Glide — BSD, MIT and Apache 2.0
  • JSON in Java (org.json) — Public Domain
  • Firebase Cloud Messaging — Apache License 2.0
  • Tabler Icons — MIT. Every glyph in the app is drawn from this set; the drawables are generated from the originals by scripts/fetch_icons.py.
  • Estenceler SemiBold, provided by Anchor Fonts — naming them is a condition of the licence. It sets the Blackbird wordmark in the app's title bar, on its sign-in screen and on the About screen, and nothing else. The font permits embedding without restriction (fsType 0), which is what shipping it inside the APK requires.
  • Animated Noto Emoji by Google — the 20 animated Blackbird reactions in the emoji picker, shipped unchanged as the Lottie files Google publishes at googlefonts.github.io/noto-emoji-animation — CC BY 4.0
  • Unicode emoji data — the list of emoji and their names that the picker and its search are built from (emoji-test.txt, Unicode 17.0) — Unicode License v3. The emoji pictures themselves are your phone's own emoji font.
  • Lottie for Android (Airbnb) — Apache License 2.0
  • vodozemac (The Matrix.org Foundation), the encryption used by Secret Chats — Apache License 2.0
  • curve25519-dalek, ed25519-dalek, x25519-dalek and subtle — BSD 3-Clause
  • RustCrypto crates (aes-gcm, sha2 and others) and the other Rust crates in the encryption library — MIT or Apache License 2.0
  • UniFFI (Mozilla) — Mozilla Public License 2.0
  • Java Native Access (JNA) — Apache License 2.0 (dual-licensed with LGPL 2.1)
  • SQLCipher for Android (Zetetic) — BSD-style licence
  • ZXing — Apache License 2.0
  • Google code scanner (Google Play services) — ML Kit Terms of Service

On this site

Five typefaces are served from this domain rather than a font CDN, so loading a page here contacts nobody else. All are under the SIL Open Font License 1.1; the licence text and every copyright notice ship alongside them at /assets/fonts/OFL.txt.

  • Cinzel and Cinzel Decorative — Natanael Gama
  • Playfair Display — Claus Eggers Sørensen
  • EB Garamond — Octavio Pardo, Georg Duffner
  • Bodoni Moda — indestructible type*

In the server

  • Go and golang.org/x/crypto — BSD 3-Clause
  • chi — MIT
  • coder/websocket — ISC
  • pgx — MIT
  • golang-migrate — MIT
  • golang-jwt — MIT
  • godotenv — MIT
  • go-redis — BSD 2-Clause
  • MinIO Go client — Apache License 2.0
  • Protocol Buffers for Go — BSD 3-Clause
  • PostgreSQL — PostgreSQL Licence
  • Redis — RSALv2 / SSPLv1
  • Caddy — Apache License 2.0
  • coturn — BSD 3-Clause

Licence texts

If anything is missing or credited incorrectly, please write to buildsevaa@gmail.com.