Open-source licences

Last updated 27 July 2026

Blackbird is built on work other people gave away. This page lists it. 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.

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

Something missing or credited wrongly? Tell me and it gets fixed: buildsevaa@gmail.com