voice-cat/PROGRESS.md

# PROGRESS — VoiceCat

Living status. **Update this file in the same commit as your work** so the next agent picks
up instantly. Newest status at the top.

- **Date convention:** ISO (YYYY-MM-DD).
- Statuses: `[ ]` not started · `[~]` in progress · `[x]` done.

---

## ▶ Where we left off / next action

- **Done:** **M2 — voice, single stream** ✓ complete (2026-06-16), now genuinely satisfied
  through the real client library, not just `test_m2_voice`'s raw-socket harness.
  `vc_stream_start/stop`, UDP binding, capture→encode→seal→send, and recv→open→decode→
  playback were all `VC_ERR_NOT_IMPLEMENTED` stubs in `core/src/core/client.cpp` even after
  `test_m2_voice` went green — meaning `vccli`/any GUI client still couldn't actually talk.
  Implemented for real this session, plus server-side `StreamInfo` broadcast
  (`SessionRegistry::set_user_stream/clear_user_stream` → `UserEvent::UPDATED`) so a second
  client's `sync_remote_streams()` learns about a peer's stream without polling.
  `ctest --test-dir build/m1-dev` — **10/10 tests** green, including the new
  `test_voice_client_abi` (two real `vc_client` instances, not raw sockets, drive the full
  UDP-binding → stream-announce → cross-client `STREAM_STARTED`/`STOPPED` event path).
  `vccli --voice` (new flag, alongside `--host/--port/--nick/--channel/--mute/--text`) was
  manually verified live: two instances see each other's mic-stream start/stop in real time.
  Note: `test_m1_integration` and `test_m2_voice` have a pre-existing intermittent flake on
  Windows in their cleanup paths (thread-join / SQLite-file-handle release race, unrelated to
  this session's changes) — rerun in isolation if one fails standalone in the full suite.
- **Next:** **M3 — multi-stream & per-channel tuning** (screen audio, listener-side per-user
  NR, jitter buffer stats API — note `voicecat.h` currently exposes no stats getter beyond
  `on_level`'s RMS meter, so a stats API needs new C ABI surface). See `docs/roadmap.md §M3`.

---

## Milestones (see [docs/roadmap.md](docs/roadmap.md) for full detail)

- [x] **M0 — Scaffolding** ✓ complete
- [x] **M1 — Control plane** ✓ complete (2026-06-15)
- [x] **M2 — Voice, single stream** ✓ complete (2026-06-16)
- [ ] **M3 — Multi-stream & per-channel tuning** ← next
- [ ] **M3 — Multi-stream & per-channel tuning** (screen audio, listener-side per-user NR)
- [ ] **M4 — Native clients** (Windows C#, macOS/iOS Swift)
- [ ] **M5 — Moderation, polish, beyond** (perms, bans, DRED; then file transfer, E2EE, …)

---

## M0 — Scaffolding ✓ (completed)

- [x] Repo layout (`core/ server/ tools/ clients/ tests/`), CMake + presets, vcpkg manifest.
- [x] C ABI header `core/include/voicecat.h` (full surface, stubbed).
- [x] Protocol source-of-truth `core/proto/voicecat.proto` (matches docs/protocol.md).
- [x] Core stubs for all six subsystems (net/crypto/codec/protocol/session/audio) + `vc_client`.
- [x] `voicecat-server` (arg parsing, config, stub run) and `vccli` (drives the C ABI).
- [x] CTest **smoke test** asserting the C ABI contract (not just "it compiles").
- [x] `.gitattributes` (LF), `.gitignore`, `.clang-format`, onboarding docs.
- **Verified:** `cmake --preset dev && cmake --build --preset dev && ctest --preset dev` → green.

---

## M1 — Control plane ✓ (completed 2026-06-15)

**Exit criterion:** ✓ `test_m1_integration` — two clients authenticate over TLS 1.3 (guest
+ Argon2id password), exchange channel and private text messages. Passes in ~1 s.

- [x] vcpkg baseline + `m1-dev` preset; `find_package` for protobuf/mbedTLS/libsodium/asio/sqlite3.
- [x] `FrameCodec` feed + emit; `encode_envelope` / `decode_envelope`.
- [x] Asio TCP acceptor + `TcpServerConn` (TLS path: blocking handshake thread + `tls_read_loop`).
- [x] `TlsContext` (mbedTLS 1.3, server cert/identity, ECDSA-P256 self-signed, TOFU on client).
- [x] `WorkerPool` (3 threads, used for Argon2id).
- [x] `Database` — SQLite, Argon2id via libsodium, `create_account` / `authenticate` / bootstrap admin.
- [x] `voicecat-admin` — account add/reset/del/list against live DB file.
- [x] `ServerIdentityManager` — generate/persist Ed25519 key + cert; fingerprint display.
- [x] `ConnSession` — WaitingHello → WaitingAuth → Authenticated state machine; full protocol relay.
- [x] `SessionRegistry` — channel tree, user map, broadcast, text routing.
- [x] `vc_client` (`client.cpp`) — full M1 C ABI: connect/TLS/ClientHello/AuthRequest/text/disconnect.
- [x] `Server::run()` — io_context, acceptor, worker pool, signal handling, `on_ready` callback.
- [x] `test_m1_integration` — M1 exit criterion. Verified green 2026-06-15.

**Key bug fixed:** double-framing in `ConnSession::send_envelope` — `encode_envelope` was
pre-framing the protobuf, then `TcpServerConn::send_frame` re-framed it. Fixed by serializing
raw protobuf bytes directly and letting `send_frame` add the single `[4-byte len]` prefix.

---

---

## M2 — Voice, single stream ✓ (completed 2026-06-16)

**Exit criterion:** ✓ `test_m2_voice` — two headless clients authenticate over TLS, bind UDP,
announce a MIC stream, send 50 encrypted Opus frames; server SFU relay re-encrypts + forwards
to the second client; B receives ≥ 25 frames and all decrypt correctly. Passes in ~4 s.

- [x] `m2-dev` preset (inherits `vcpkg-base`, binaryDir `build/m2-dev`); `m1-dev` also builds all M2 code.
- [x] `core/CMakeLists.txt` — `find_package(Opus)`, `find_path(MINIAUDIO_INCLUDE_DIR)`.
- [x] `core/src/net/voice_frame.h` — 14-byte UDP header (type/flags/codec/ssrc/seq/ts), serialize/parse, `make_udp_binding_packet`.
- [x] `SodiumMediaCrypto` — ChaCha20-Poly1305 AEAD; counter-nonce; 64-bit sliding-window anti-replay; `derive_send/recv` from TLS RFC 5705 exporter.
- [x] `OpusEncoder` / `OpusDecoder` — libopus 1.6, FEC, DTX, PLC (free; nullptr → decoder extrapolates).
- [x] `UdpMediaChannel` — async UDP socket (asio); thread-safe `send_to`; async recv loop.
- [x] `JitterBuffer` — per-ssrc, EWMA jitter estimation, adaptive depth 20–200 ms, late-drop at 500 ms.
- [x] `AudioEngine` — miniaudio capture+playback; `inject_capture()` bypass for headless tests; per-ssrc RemoteStream with OpusDecoder + JitterBuffer.
- [x] `ApmProcessor` — `ApmPassthrough` stub (VAD always open); WebRTC APM deferred until M3.
- [x] `on_tls_ready` callback in `TcpChannelCallbacks` — server derives and stores media AEAD keys immediately after TLS handshake.
- [x] `ConnSession` M2 — `udp_token` generated at construction; included in `AuthResult`; `handle_udp_binding` (verifies token, TCP ack); `handle_stream_announce` (assigns SSRC via registry); `udp_media_port` in `ServerHello`.
- [x] `SessionRegistry` M2 — `register_udp_token`, `find_by_udp_token`, `register_udp_endpoint`, `find_by_udp_endpoint`, `assign_ssrc`, `find_channel_sessions`, `user_channel`.
- [x] `MediaRelay` — SFU UDP relay; `kFrameUdpBinding` → endpoint binding; `kFrameVoice` → decrypt/re-encrypt/forward to channel members.
- [x] `Server::run()` — creates and binds `MediaRelay`; passes media port to `ConnSession`; wires `on_tls_ready` to derive per-connection media AEAD keys.
- [x] `test_voice_frame` — header round-trip, big-endian layout, binding packet format.
- [x] `test_media_aead` — seal/open round-trip, anti-replay, tamper detection, multi-packet sequence.
- [x] `test_opus_codec` — encode/decode round-trip energy check (within 3 dB), PLC, frame-samples helper.
- [x] `test_m2_voice` — M2 exit criterion (raw-socket harness). Verified green 2026-06-16.

**Follow-up (same day):** the above made `test_m2_voice` pass, but `vc_client`'s public voice
methods were still stubs — the *actual* M2 exit criterion ("two vccli/early-GUI clients talk")
wasn't met. Closed the gap:

- [x] `core/src/core/client.cpp` — real `stream_start`/`stream_stop`/`set_self_mute`/
  `set_remote_stream`; UDP-binding handshake (`start_udp_binding`/`handle_udp_binding_ack`/
  `finish_udp_binding`); media key derivation from `tls_` (RFC 5705 exporter); `run_udp_recv`
  (AEAD-open → `JitterBuffer::Frame` → `audio_engine_.push_recv_frame`); `on_capture_frame`
  (encode → seal → `sendto`); `sync_remote_streams` (diffs a `User` proto's `streams` against
  `remote_streams_`, wiring up `OpusDecoder`s and emitting `STREAM_STARTED`/`STOPPED`).
  `set_input_device`/`set_input_mode`/`set_push_to_talk`/`list_devices` remain
  `VC_ERR_NOT_IMPLEMENTED` — no device-enumeration backend yet; scoped to M3 (VAD/PTT).
- [x] `core/src/session/session.cpp/h` — `SessionModel::find_user`, `find_user_by_ssrc`,
  `Stream{stream_id, ssrc, kind, label, sample_rate, frame_ms}`.
- [x] `server/src/conn_session.cpp/h` — `handle_stream_announce`/`handle_stream_stop` now
  broadcast via `SessionRegistry::set_user_stream`/`clear_user_stream` → `UserEvent::UPDATED`.
- [x] `server/src/session_registry.cpp/h` — `set_user_stream`/`clear_user_stream` (mutate a
  user's `StreamInfo` list, return the updated `User` proto for broadcast).
- [x] `tests/test_voice_client_abi.cpp` — drives two real `vc_client` instances through
  `vc_connect`/`vc_authenticate_guest`/`vc_stream_start`/`vc_stream_stop`; asserts client B
  observes client A's `STREAM_STARTED`/`STOPPED` events. Verified green 2026-06-16.
- [x] `tools/vccli/src/main.cpp` — argv parsing (`--host/--port/--nick/--channel/--voice/
  --mute/--text`); `--voice` starts a MIC stream and blocks on SIGINT, printing `on_event`
  callbacks live (unbuffered stdout — MinGW/MSVCRT treat `_IOLBF` as full buffering for
  non-console streams). Dropped the originally-planned `--voice-loopback` and the
  `tx=N rx=M lost=K jitter=J` stats line: `voicecat.h` exposes no PCM-injection hook or
  jitter/loss stats getter publicly, only `on_event` + `on_level` (RMS). Manually verified:
  two `vccli --voice` instances see each other's stream start in real time.

---

## Decisions log

All architecture/scope decisions are settled and recorded in
[docs/roadmap.md §2 "Resolved decisions"](docs/roadmap.md) and reflected across `docs/`.
If you make a *new* decision, record it there and link it here.

---

## How to update this file

1. Check off tasks as you complete them; flip a milestone to `[x]` only when its **exit
   criterion test** passes.
2. Keep the **"Where we left off / next action"** block at the top accurate — it's the first
   thing the next agent reads.
3. When you start a milestone, copy its task list from `docs/roadmap.md` into a section here.