Files

engineer e39cec3847 fix(launch): Expo SDK 52->54 in HN/Reddit copy; add reply-flow E2E evidence; version refs

- Launch posts claimed Expo SDK 52 but app is on SDK 54 (factual accuracy
  before public posting — HN/Reddit devs check this)
- docs/qa/REPLY-FLOW-E2E-2026-06-08.md: verified send->streaming reply works
  against the live opencode server via app-identical sdk.ts calls (free model);
  closes the 'opencode can't reply in CI' residual at the data-contract level
- owner-submissions.md: 0.4.3 -> 0.4.4

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-08 07:42:19 -07:00

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r/androiddev — copy-paste ready

Subreddit: r/androiddev (~250k+ members, professional Android engineers) Flair: Open Source if available; otherwise Showcase / App Showcase. NOTE: r/androiddev is strict — pure "check out my app" promo posts get removed. This must read as an engineering write-up, not an ad. The framing below leads with the hard technical problems (SSE polyfill, custom diff renderer, async stream coordination), which is what survives moderation here. Rules that matter here: No low-effort self-promo; Showcase posts must include technical substance. Don't open with download links — open with the engineering. Put install links at the bottom. Be ready to discuss code. Best time: Weekday mornings ET. This sub also has a recurring "Anything Goes / App Feedback Thread" — if your standalone post is borderline, the weekly thread is a safe fallback. {{PLAY_URL}} = https://play.google.com/store/apps/details?id=cc.agentlabs.opencode once approved.

Title:

Building a streaming AI-agent client in RN/Expo: SSE polyfill quirks, a WebView-free diff viewer, and coordinating two async streams for tool-call approval

Body:

I just shipped OpenCode Mobile (open source, MIT) — an Android client for the opencode AI coding agent. opencode runs as a CLI/server with an HTTP + SSE API; the app speaks that API and gives sessions a native UI. A few implementation problems were interesting enough to write up.

1. SSE on React Native. RN has no native EventSource. The web polyfill mostly works, but Android's OkHttp follows redirects and drops the Accept: text/event-stream header on the hop, which silently breaks reconnects against tunneled servers (Cloudflare/ngrok love to redirect). Fix was a custom fetch wrapper that re-sets the header on every hop and handles reconnect/backoff manually.

2. Diff viewer without a WebView. I render line-level diffs with a custom parser feeding a FlatList rather than embedding a WebView. Keeps dark-mode theming consistent with the rest of the app, avoids the memory/startup cost of a browser engine, and makes long diffs scroll cleanly.

3. Tool-call approval = coordinating two async streams. opencode pauses before destructive actions (file writes, shell commands) and waits for approval. So you have the inbound SSE stream and an outbound user decision that must rendezvous. I model it as a React Query mutation fired on approval plus an optimistic UI update that unblocks the stream client-side while the server confirms. Surfaced as a bottom sheet that interrupts the stream.

Stack: Expo SDK 54, TypeScript, React Query for server state, Zustand for local state, expo-local-authentication for biometric gating (app-open + per-send), expo-secure-store (Android Keystore) for connection secrets, Sentry (opt-in, off by default), signed AAB on every tag via GitHub Actions + EAS.

Source: https://github.com/dzianisv/opencode-mobile

Install / try it: https://dzianisv.github.io/opencode-mobile/download/ · F-Droid repo: https://dzianisv.github.io/opencode-mobile/fdroid/repo · APK: https://github.com/dzianisv/opencode-mobile/releases/latest · Google Play: in review — {{PLAY_URL}}

Happy to get into any of it — the SSE + approval coordination was the part I rewrote the most.

3.3 KiB Raw Blame History

r/androiddev — copy-paste ready

3.3 KiB

Raw Blame History