Development Update — July 7

A big day for skychat: the mesh messenger grew two features that make it a real communication tool rather than a text demo — file sharing and real-time voice — both built on the same principle that everything rides the encrypted skywire transport and nothing touches the clearnet. Underneath that, a memory leak that had been quietly bloating the transport-discovery server to 4 GB got root-caused and fixed, and the committed browser-visor blob finally got its bloated git history pruned. This post walks the arc: the leak, file sharing on native and in the browser tab, and the voice stack from RFC to a working call.

Skywire: Plugging the TPD Accept-Side Leak

The transport-discovery server had been climbing to ~4 GB of resident memory and spending most of its time in GC — a slow leak that only showed under real fleet churn. Two fixes close it.

3409 fix(cxo): close the superseded conn on peer reconnect (accept-side leak) is the root cause. When a peer reconnected, DMSG.addConn overwrote d.cs[pk] with the new connection without closing the one it replaced — so the old Conn’s read-loop goroutine blocked forever on a socket nobody would ever close again, one leaked connection (and goroutine, and buffers) per reconnect. On a server like TPD that every visor connects to, reconnect churn accumulated to gigabytes. The fix makes addConn close the superseded connection outside the lock, with an identity check in closeConn so it never closes the wrong one.

3408 fix(cxo): back off the fill-break reconnect kick (TPD accept-side leak) fixes the amplifier. A fill-break “kick” added earlier reconnected instantly with no backoff, so against TPD’s un-fillable 8 MB all-transports feed it spun in a tight reconnect loop — turning the latent addConn leak into a fast one. An exponential backoff (base 2 s, cap 60 s, reset on a successful fill) turns the tight loop back into an occasional retry, so the leak fix has time to actually settle the connection.

Together these take TPD from a GC-bound 4 GB back to a flat memory profile under the same churn.

Skychat: File Sharing, Telegram-Style

3414 feat(skychat): file sharing — Telegram-style, 1:1 + group, over dmsg/skynet makes a file just another message in the conversation. The design mirrors the voice work: a reusable offer→accept→chunked-stream primitive (pkg/skychat/xfer) where the sender announces an offer, the receiver auto-accepts if it’s an established chat or a shared group, and the bytes stream out of band on a dedicated port (skyenv SkychatFilePort) so a large transfer never blocks the chat conn. Every chunk is length-prefixed and the whole transfer is verified with a trailing sha256; the accept/decline handshake happens before any bytes move, so a declining peer never receives the body. It works 1:1 over the non-CXO framed skychat and to a group by fanning the file out to each current member — all over the encrypted dmsg or skynet transport, never the clearnet. A skywire cli skychat send-file command exposes it to the CLI (and CI), matching the GUI.

3415 feat(wasm-hv): file sharing for the browser-tab skychat (parity with native) brings the exact same primitive to the browser visor, wire-compatibly, so a browser tab and a native visor exchange files with each other. The only difference is that a tab has no filesystem: a received file buffers in memory and is handed to the page as a Blob download, and a sent file’s bytes come from a File the page reads — surfaced through new skychatSendFile / skychatFile bridge calls and a 📎 attach button plus download link in the desktop chat window. This was validated live in both directions between a native visor and a browser tab, byte-identical and sha256-verified.

Skychat: Real-Time Voice on the Encrypted Mesh

The day’s largest new surface is 1:1 voice, built in three PRs from design to a call.

3411 docs(skychat): voice RFC — real-time voice with all media on the encrypted mesh sets the constraint that shapes everything: WebRTC is used only as a media library (Opus, RTP, jitter handling), with the skywire transport replacing ICE and DTLS-SRTP entirely — so audio rides the same Noise-encrypted mesh path as everything else and never opens a raw-internet ICE candidate. Media travels on the faithful-UDP datagram route groups already wired into the router.

3412 feat(skychat): voice core — signaling (dmsg+skynet, one port) + RTP media is the transport-agnostic engine: a signaler that exchanges invite / accept / decline / hangup over both dmsg and skynet on the same port, and a session that paces PCM frames through a codec into length-prefixed RTP over a skywire stream. It ships with a passthrough PCM codec and pluggable mic/speaker seams so the whole control-and-media plane runs and is unit-tested before any real audio device is attached.

3413 feat(skychat): wire voice into the visor — init + RPC + CLI brings that engine up on a running visor: it listens for inbound call signaling over dmsg and skynet, dials outbound calls skynet-first with a dmsg fallback, and exposes voice call / voice hangup / voice list over RPC and the CLI. For now the visor auto-answers with silent media — accepting a call leaks no audio — a deliberate placeholder until a real audio backend and an explicit-answer consent flow land.

Skywire: Pruning the Browser-Visor Blob History

chore(wasm-visor): re-add embedded blob after history prune closes out a repository-hygiene issue. The committed browser-visor blob (pkg/wasmhv/wasmbin/wasm-visor.wasm.gz) is regenerated and re-committed on every wasm change, and git keeps every past version forever — ~40 copies had accumulated to roughly 350 MB of a bloated .git. A one-time git-filter-repo pass (now scripted behind a make prune-wasm-embed-history target) stripped every historical copy and re-added only the current blob, so history holds it exactly once — reclaiming the space while keeping the blob committed so a from-source build still works without a wasm toolchain.