Blog

Engineering deep-dives, incident reports, and release notes from the Foxl team.

FeaturedJul 22, 20266 min

Five Releases in One Day

v0.4.15 through v0.4.19 in a single day - every one shipped by Foxl Code working on the Foxl monorepo itself. Human taste, agent execution, shared memory: this is the product thesis on a good day.

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28 articles

Deep diveJul 21, 202611 min

Hearing the Whole Meeting: How an Empty AirPods Transcript Rewrote Two Releases

One bug report - "I recorded a meeting with AirPods and the transcript came back empty" - led through a macOS permission that fails silently, an inaudible test tone, a GPL driver we chose not to bundle, a WebKit limitation with no escape hatch, a native Swift recorder, and a ten-item audit of what makes a phone app worth being an app. The story of v0.4.13 and v0.4.14.

Audio capture / macOS permissions / iOS / Mobile UX / Reliability

IncidentJul 16, 20265 min

Designing Connection Ownership for Always-On AI Agents

v0.4.7 fixed duplicate device sessions and fenced stale desktop sockets, then v0.4.8 and v0.4.9 exposed the missing distinction between liveness, connection-generation ownership, and in-flight request correlation. This is the full incident sequence and the contract that replaced it.

Session identity / Token rotation / WebSocket resilience

IncidentJul 12, 20266 min

Your Meeting Was Transcribed Twice. Deleting Code Fixed It.

Two independent transcription pipelines appended two rows for the same utterance when the microphone re-heard speaker output. Mixing both captures into one ASR stream removed the two-writer failure mode and let us delete the similarity filter.

Audio capture / Streaming transcription / Web Audio

IncidentJul 12, 20265 min

Choosing a Source of Truth for Agent Conversations

The UI ledger and the agent snapshot drifted through head trimming, synthetic cancel turns, and interrupted saves. The fix made user-visible SQLite history authoritative on normal cold restores and kept snapshots as derived history or fallback data.

Data consistency / SQLite / Agent memory

IncidentJun 26, 20265 min

The Checksum Byte That Ate Your Long Answers

Foxl replies were truncating mid-sentence on long answers. The cause was a single byte. Our relay decoded Amazon Bedrock's binary event-stream as if it were text and brace-scanned for JSON - so a CRC32 checksum byte equal to 0x22 (a double-quote) flipped the parser into string mode and silently swallowed the rest of the stream. A captured 32 KB stream dropped 70 of 119 events. Here is the binary-framing parser that fixed it, and the fixture test that keeps it fixed.

Binary protocols / Streaming / Amazon Bedrock

Deep diveJun 8, 20267 min

Building Foxl Mobile from a Shared React Codebase

Foxl v0.3.0 reused a shared React source tree across hosted web, Electron, and a Capacitor iOS host, with runtime-specific builds and platform integration. The hard parts were keyboard docking and safe-area ownership without offsetting touch targets.

iOS / Capacitor / WebView layout