opencode-android

A native Android client (Kotlin + Jetpack Compose) for the opencode serve HTTP API.

Application id: soy.iko.opencode

Status

Milestones M0–M7 complete:

• M0–M4: connect to a server → list/create/delete sessions → chat with live SSE streaming of the assistant's reply. Tool calls, reasoning, and token/cost are rendered.
• M5: per-session model picker (GET /config/providers); permission prompts — the agent's permission.updated asks surface as an allow-once / always / reject dialog, answered via POST /session/:id/permissions/:permissionID, so tool runs don't stall; file browser + viewer (/find/file fuzzy search, /file directory listing, /file/content read-only view); reconnect banner (live SSE connection state) and a real Settings screen (theme mode, persisted).
• M6: markdown rendering of assistant text (headings, code blocks, lists, blockquotes, inline bold/italic/code/links/strikethrough); rich diff/patch rendering — tool outputs and file-viewer content that contain unified diffs are syntax-highlighted (added lines green, removed lines red, hunk headers); agents & commands UI — GET /agent powers a per-message agent picker (sent via the agent field on the prompt body); GET /command powers a slash-command runner that sends the command template with its configured agent; multi-server quick-switch — the session list title is a dropdown that lists all saved servers and switches instantly without navigating back.
• M7: UX polish pass. Draft retention (failed sends restore your text with a Retry action); destructive-action confirmations (delete session / remove server); the app bar now shows the real session title; smart auto-scroll that won't fight a reader who scrolled up, with a jump-to-latest FAB; long-press to copy assistant markdown, plus copy buttons on tool output and diffs; expandable tool output (Show more / Show less) instead of a hard truncation; session list with relative timestamps, last-message previews, and a search filter; tappable file-browser breadcrumbs; a "connected" marker on the active server; permission dialog with clear action hierarchy; dynamic "Thinking…" → "Thoughts" reasoning label; back-press guard while an agent is running; polished empty states; richer Settings (Dynamic Color / Material You toggle, version info, manage-servers link); haptic feedback; and a file viewer with line numbers, copy, and share. The session list also supports renaming a session (PATCH /session/:id).

Architecture

• Ktor 3 (OkHttp engine) for REST + the long-lived GET /event SSE stream.
• kotlinx.serialization with sealed polymorphism for opencode's discriminated unions (Part/type, MessageInfo/role, ToolState/status, BusEvent/type). Unknown discriminator values fall back to Unknown* variants (OpencodeJson) so a new server release can't break decoding.
• Manual DI (AppContainer on the Application) — no Hilt/KSP.
• Unidirectional state: EventStreamClient exposes the SSE stream as a hot SharedFlow; SessionRepository reduces events into per-session message state; ViewModels expose StateFlow; Compose collects with collectAsStateWithLifecycle.
• The repository subscribes to /event before the prompt POST so no early streamed part is missed.

Source map: data/network (Ktor, SSE, JSON), data/model (wire models), data/repo (reducer + profile persistence), di (container/connection), ui/<feature> (Compose screens).

Build

nix develop              # JDK 17, Gradle 8.14.4, Android SDK 35, aapt2 override
./gradlew assembleDebug  # -> app/build/outputs/apk/debug/app-debug.apk
./gradlew assembleRelease  # R8-minified + resource-shrunk release APK
./gradlew testDebugUnitTest   # JVM tests for the JSON/serialization layer

Install & run

adb install -r app/build/outputs/apk/debug/app-debug.apk
adb shell am start -n soy.iko.opencode/.MainActivity
adb logcat --pid=$(adb shell pidof soy.iko.opencode)

Connect to a server

On the dev host:

opencode serve --hostname 0.0.0.0 --port 4096

In the app, add a server with base URL http://<host-lan-ip>:4096. If the host is reachable only over USB, use adb reverse tcp:4096 tcp:4096 and point the app at http://127.0.0.1:4096.

Auth is optional: opencode has no auth by default. If the server runs with OPENCODE_SERVER_PASSWORD=..., enter username opencode (the default) and that password — the app sends HTTP Basic auth. The app permits cleartext HTTP (opencode serves plain http://).