Engine numbers never reached the store: download.get after a correctly-finished
download reported sizeBytes: null, downloadedBytes: 0, speedBps: 0, resumable:
false, segments: 0, segmentDetail: [] — segments: 0 breaks the frozen contract
(TaskSummary.segments is minimum:1, required).
- Scheduler::tick() now probes (EnginePort::probe) before every start(), persisting
sizeBytes/resumable/validators via Tasks::set_probe_result before a byte moves,
then starts the engine with that ProbeResult as probe_hint.
- Scheduler::persist_progress() (new) writes downloadedBytes/speedBps/segments/
segmentDetail from the engine's Progress. Called from progress_snapshot() (the
250ms tick) *and* once more from on_engine_state right before release()/unmap on
every terminal transition, so a task that finishes between two ticks — the common
case for anything small or fast — still leaves real numbers instead of the
pre-persistence defaults.
- TaskSummary.segments is sourced from segments.size() when the task has any
(matching what actually lands in segmentDetail, per the schema's "exactly
segments entries"), falling back to the engine's effective_segments (budget
slots *held*, not necessarily physical range count) only pre-segmentation.
- Tasks::set_final_bytes tops up on_finished's byte count as a last-resort
backstop.
- store/segments.{cpp,hpp}: read/write access to the segments table behind
TaskDetail.segmentDetail. Wired into daemon/CMakeLists.txt.
- migrations/0002: speed_bps on tasks and segments; fixes segments.state's CHECK
to include 'pending' (0001 omitted it, so a pre-connect snapshot could never be
written).
- store_migrations_test's forward-only loop faked "released version N" by setting
the user_version pragma alone, with no real schema underneath — never exercised
until 0002 existed. Fixed to actually build the db through migrations 1..N first.
Verified against real veloxd + tools/testserver (not just unit tests):
download.list/download.get correct immediately after completion and after a
daemon restart, with saveTo.allowedRoots pointed at an isolated dir.
Observed but not fixed (CORE, not this lane, noted in deferrals.md): Progress.
speed_bps reads back 0 for the whole lifetime of a live throttled download in the
same E2E check, despite downloadedBytes visibly advancing. DAEMON passes it
through unmodified; filed rather than worked around.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01GRDjHGgpYmMoPE2UFbe7pP
Velox Download Manager (VDM)
An IDM-class download manager for Ubuntu 26.04 LTS: multi-segment accelerated HTTP(S) downloading, resume, categories and automatic file distribution, queues and scheduler, speed limiter, a Firefox extension that captures downloads automatically, and clipboard link capture.
Name is a placeholder. Binaries are
veloxd,velox-gui,velox,velox-nmhost. Rename before first release if you want something else — do it in M0, never later.
Status
Phase M0 — scaffolding. No implementation code exists yet. This repository currently contains the architecture, the wire contract, the roadmap, and one brief per build lane so that several agents can work in parallel without colliding.
Start here:
| Document | What it answers |
|---|---|
| docs/01-architecture.md | Process model, why four binaries, framework choices and why |
| docs/02-roadmap.md | Milestones M0–M7, what runs in parallel, exit gates |
| docs/03-gui-spec.md | IDM-parity UI: every window, dialog, column, menu |
| docs/04-engine-design.md | Segmentation, resume, buffers, rate limiting, disk I/O |
| docs/05-extension-spec.md | Firefox capture, transports, pairing, media grabber |
| docs/06-risks-and-spikes.md | Snap Firefox, Wayland clipboard, and the other landmines |
| docs/07-packaging.md | .deb/PPA, Flatpak, AMO signing, install layout |
| contracts/README.md | The interface. Both sides build against this |
| CLAUDE.md | Rules of engagement for agents working in this repo |
Per-lane briefs live in docs/agents/ — one per agent, each with an owned directory list, a definition of done, and the files it must never touch. To dispatch the agents, use docs/agents/PROMPTS.md — six copy-paste prompts plus the worktree commands and the wave order.
Architecture in one picture
┌────────────────────┐ native messaging (stdio JSON) ┌──────────────┐
│ Firefox extension │◄───────────── or ──────────────►│ velox-nmhost │
│ (MV3, TS) │ loopback WS 127.0.0.1 + token └──────┬───────┘
└────────────────────┘ │
│
┌────────────────────┐ ▼
│ velox-gui (Qt 6) │◄──── JSON-RPC 2.0 over Unix socket ──► ┌─────────────┐
└────────────────────┘ $XDG_RUNTIME_DIR/velox/velox.sock │ veloxd │
│ (daemon) │
┌────────────────────┐ │ │
│ velox (CLI) │◄───────────────────────────────────────┤ libveloxcore│
└────────────────────┘ └──────┬──────┘
│
SQLite + sparse files
The daemon owns all state and all sockets. The GUI is a view — closing it does not stop a download. The extension never touches the disk; it hands URL + headers + cookies to the daemon and gets a task id back.
Repository layout
vdm/
├── contracts/ ⭐ Wire contract: JSON Schema, fixtures, codegen. Frozen per version.
├── core/ C++23 libveloxcore — engine. No UI, no RPC, no SQL.
├── daemon/ C++23 veloxd — RPC server, scheduler, queues, SQLite store.
├── gui/ C++23 velox-gui — Qt 6 Widgets, IDM-parity UI.
├── cli/ C++23 velox — scriptable client.
├── nmhost/ C++23 velox-nmhost — Firefox native-messaging bridge (thin pipe).
├── extension/ TS Firefox MV3 WebExtension.
├── tools/
│ ├── mockd/ TS mock daemon — lets GUI + extension work before veloxd exists.
│ ├── testserver/ Deliberately hostile HTTP server (no Range, flaky, redirects, auth).
│ ├── bench/ Throughput and CPU benchmarks.
│ └── fuzz/ libFuzzer targets for parsers.
├── tests/
│ ├── conformance/ Protocol suite. Every lane must pass it. Gate for merging.
│ ├── integration/ veloxd + testserver.
│ └── e2e/ Playwright: real Firefox + real daemon + real file on disk.
├── packaging/ debian/, flatpak/, appimage/, native-host manifests.
└── docs/ Everything above, plus adr/ and agents/.
Toolchain bootstrap
Surveyed on this machine 2026-09-09 — most of it is already installed:
| Present | Version |
|---|---|
| git · cmake · ninja · g++ · gdb | 2.53.0 · 4.2.3 · — · 15.2.0 (C++23 ready) |
| qt6-base-dev · qt6-tools-dev · qt6-tools-dev-tools | ✓ |
| libcurl4-openssl-dev · libsqlite3-dev · nlohmann-json3-dev · libssl-dev | ✓ |
| libavformat-dev · libavcodec-dev · ffmpeg | ✓ |
| clang-format · clang-tidy · python3 · pkg-config | ✓ |
| python3-jsonschema · python3-referencing (conformance static runner) | ✓ |
Only these four are missing:
sudo apt update && sudo apt install -y \
qt6-svg-dev \ # GUI: SVG icon rendering
libsecret-1-dev \ # DAEMON: Secret Service for site logins
nodejs npm \ # EXT + PROTO: extension build, mockd, conformance runner
clang # optional: libFuzzer targets in M7
Node in the 26.04 archive may lag; if the extension toolchain needs 22+, use nvm.
Verify with cmake --preset dev && cmake --build --preset dev once lane CORE lands its
first target. Note CMake 4.2.3 is installed — newer than the 3.28 floor in
CMakeLists.txt, and it hard-errors on cmake_minimum_required below 3.5, so no
dependency may ship a pre-3.5 CMake file.