Chaya

A native Android browser that finds the media on a page, and saves it.

Open a page → Chaya finds the video → tap → saved, under the video's real name. It handles direct files, HLS/DASH streams with a quality picker, and links from YouTube, Instagram, TikTok and X, with pause, resume and retry throughout.

Chaya (Sanskrit): light and shadow, speed. The interface follows: fluid, assured, soft: calm surfaces, confident motion, zero clutter.

Install: download app-release.apk from Releases and allow installs from unknown apps when asked.

---

What it does

Browse	A full browser: tabs, address bar, back/forward, fullscreen video, a session that survives leaving the page
Find	Network sniffing and an injected page scanner (Shadow DOM, iframes, fetch/XHR) run together; extensionless media is checked only when you ask
Make sense of it	The page's main video comes first with its title; likely ads are folded away; stream pieces are hidden; one entry per quality
Video sites	Paste, share or browse a YouTube, Instagram, TikTok or X link: yt-dlp, running on the phone, finds the qualities; picture and sound are joined into one MP4. Instagram and X posts with pictures (gallery-dl) save every photo
Block ads	EasyList and EasyPrivacy, the lists uBlock Origin starts with, block ad and tracker requests, hide ad boxes and refuse ad pop-ups; off for any site with one switch
Download	Files over OkHttp with Range resume; HLS/DASH through Media3; a foreground service with progress, pause and cancel
Keep	Download history in Room with explicit migrations; finished files appear in your Movies, Music, Pictures or Downloads

Privacy by construction

• The page-to-app bridge needs a 256-bit capability issued per navigation, given only to the top document; cross-origin iframes cannot call native code.
• Media-type checks are same-origin, redirect-free and opt-in, so your cookies cannot be sent elsewhere.
• Diagnostics stay on the phone (addresses scrubbed before logging); your sign-in on a video site is used only when you tap to allow it, and the temporary copy is deleted right after.
• The ad blocker's lists are fetched weekly from easylist.to with nothing about you attached; blocked requests never leave the phone.
• No analytics, no ads, no account, no server. Details in PRIVACY_POLICY.md.

---

Engineering highlights

• A tested state machine. QUEUED → DOWNLOADING ⇄ PAUSED → COMPLETED | FAILED | CANCELLED, with task IDs shared by memory, Room and the downloaders, so a download killed mid-way resumes instead of starting over.
• Failures are classified. Network, HTTP status, storage full, unsupported, could-not-combine: each has a plain message and decides whether Retry is offered.
• Two-file downloads that survive anything. Picture, then sound, then a lossless MediaMuxer join. What is left to do is worked out from the files present, so pause, a killed app and a failed join all recover without downloading again.
• Tests at every level. JVM and Robolectric tests, MockWebServer transfers over real HTTP, a Media3 stream pipeline served locally, pytest for the Python engine, on-device tests for yt-dlp, QuickJS and the join, and an emulator walkthrough that uploads screenshots.
• A design system in code. OKLCH-derived palette (warm Porcelain light, Violet Charcoal dark), spring-only motion tokens, one component vocabulary. See DESIGN.md.

How it fits together: docs/ARCHITECTURE.md.

---

What it doesn't do

No DRM-protected services, no MediaSource-only players outside the supported sites, no live broadcasts. Chaya is for media you own or have permission to download. See LIMITATIONS.md.

---

Project map

app/src/main/java/com/chaya/app/
├── adblock/       ad blocker: filter engine (plain Kotlin), lists and weekly update, per-page sessions
├── browser/       WebView shell, address bar, view model
├── detection/     interceptor, JS bridge, ranking, naming, ad hosts, content-type checks
├── platform/      video-site links: matcher, yt-dlp engine, JS solver, format selection, sign-in
├── download/      DownloadManager, OkHttp downloader, MP4 join, errors, foreground service
├── streaming/     Media3 HLS/DASH downloads and manifest tracks
├── database/      Room (explicit migrations)
├── diagnostics/   event log, crash reports, local insights
├── downloads/     Downloads screen
└── ui/            theme, sheets, player, navigation
app/src/main/python/chaya_engine/   yt-dlp wrapper run through Chaquopy
app/src/main/assets/detection/      the injected page scanner
app/src/main/assets/adblock/        EasyList and EasyPrivacy as shipped

The ad lists in app/src/main/assets/adblock/ are EasyList and EasyPrivacy, by The EasyList authors, used under the Creative Commons Attribution-ShareAlike 3.0 licence.

Docs

docs/ARCHITECTURE.md	How the app works, and where its tests live
docs/BUILD_AND_TEST.md	Toolchain, commands, CI, releases, a manual check
docs/ROADMAP.md	What is merged, released and next
PRODUCT.md · DESIGN.md	Product register and design system
LIMITATIONS.md · PRIVACY_POLICY.md	Scope and privacy
CLAUDE.md	Guide for coding agents
docs/history/	Finished plans and research

Build from source

JDK 17, Android SDK 36, Gradle 8.14.3 and Python 3.13, then gradle testDebugUnitTest assembleDebug. There is no checked-in wrapper; see docs/BUILD_AND_TEST.md.