dotStream

dotStream

Own software for the AJAZZ AKP153E stream controller, because the bundled software is not good.

Not an Elgato-compatible plugin host. Deliberately.

Let an assistant build your pages

Setting up a deck is tedious. Fifteen keys, each needing a shortcut you have to look up, a label and an icon, and you do it again for every application. Most people fill in four keys and never touch it again.

dotStream speaks MCP in both directions, so an AI assistant can do that part.

You: set up an Excel page for me

The assistant proposes thirteen keys with shortcuts, labels and icons already filled in. They appear on the deck with Accept, Reject and Later. You press one physical key.

It works because the assistant can look things up that you would otherwise have to. Ask for an OBS page and it queries OBS for your actual scene names and audio sources before proposing anything. Ask for ribbon commands and it writes them as key sequences, so Alt, H, M, C becomes a Merge and Centre key even though Excel has no shortcut for it.

A person always presses Save. The assistant fills in, you decide. A physical button has to do what you believe it does, so nothing is placed without you seeing it first, on the deck, next to the two keys that accept or reject it.

An assistant can also ask you something and wait for the answer on a physical key, which is the other direction and the reason this is a server rather than a plugin.

Switch it on under File → Agent bridge (MCP). Off by default.

If yours says something else on it

The same hardware is a Mirabox HSV293S underneath, sold under a pile of names. If you own any of these, this is for you too:

AJAZZ AKP153E · Mirabox HSV293S · MBOX 293S · MRSVI 293S · Basicolor HSV293S · Mars Gaming MSD-Pro · Soomfon CN003 · HALCONTORNO HSV293 Slim

Decks are found by their vendor HID usage page rather than by USB identifiers, precisely because those differ between batches and rebrands, so an unlisted variant has a good chance of just working. If the pictures come out cropped or offset, View → Calibrate cells fixes it without a rebuild. And if you have one that works, or one that does not, please open an issue and say which — that list is only as good as what people report.

Status

Running on real hardware. The HID transport is written and measured against an AKP153E: brightness, image upload, key presses and releases, and the full 6×3 cell map, all confirmed on the device.

You do not need the deck to start. dotStream runs against a built-in simulator with the same eighteen cells, the same indices, and the same behaviour down to reporting press and release separately — so a long press or a key that repeats while held works identically on screen and on the desk. Set up your pages while yours is in the post; when it arrives, plug it in and everything is already there.

With a deck attached the two run side by side: the window mirrors the hardware, and a click on either counts. Useful when the deck is behind a monitor, or when you are working somewhere else.

✅	18-cell 6×3 model, key ↔ protocol index mapping
✅	Cell renderer: gradients, icons, labels, gauge rings, pixel hashing
✅	Icon extraction from shell:AppsFolder at 256×256 with real alpha
✅	Upload controller: dirty-tracking, coalescing, priority queue
✅	Simulator transport with realistic per-upload latency
✅	Info-cell widgets: CPU, RAM, clock
✅	File / Help menu, About, dark title bars
✅	Page stack: press a running app's key to open its own page, with Back
✅	Action palette — drag apps and actions onto keys
✅	Media session integration: transport, live play state, album art
✅	App selection dialog, persisted to %APPDATA%\dotStream\selection.json
✅	Pages and key assignments persisted to %APPDATA%\dotStream\profile.json
✅	Tray icon, close-to-tray, deliberate exit
✅	Follows the focused app, with manual-navigation pinning
✅	MCP server — an agent can ask a question on physical keys and wait
✅	HID transport — measured against the hardware, not taken from the notes
✅	Hot-plug: plug the deck in at any point and it comes to life
✅	Hotkeys, sequence macros, text macros, run a program, open a link
✅	Steam games, which the Windows shell cannot see at all
✅	Cell calibration for variants nobody has measured
✅	Start with Windows, into the tray
✅	OBS Studio — scenes, recording, streaming and mute, with keys that light up
✅	Discord — mute, deafen, camera, screen share, and voice channels that fill themselves
⬜	Generic MCP client action — a key that calls someone else's tool
⬜	Folders and a page-switch key

Full list in TODO.md.

Installing

⬇ Download the latest release

Both downloads are self-contained — no .NET runtime to install first. Requires Windows 10 2004 (build 19041) or newer, x64.

Download	For
dotStream-<version>-win-x64-setup.exe	Normal install, Start menu entry, uninstaller. Per-user, so no UAC prompt.
dotStream-<version>-win-x64-portable.zip	A single exe. Writes nothing outside %APPDATA%\dotStream.

Take the installer if you are not sure. The portable zip is for a USB stick, a locked-down machine, or trying it without installing anything.

Settings live in %APPDATA%\dotStream\ and are deliberately left alone by the uninstaller:

File	Holds
profile.json	The deck layout — pages and key assignments
selection.json	Which applications appear in the palette
labels.json	Custom key names, keyed by application, not by key
	Widget choice and colours live in profile.json with the cell
text.json	Label font, weight, formatting, antialiasing and size
fonts\	Drop .ttf or .otf files here to add them to the font list

Fonts are scanned at startup, so a newly added file appears after a restart. File › Open fonts folder opens it.

Windows will warn you, and that is expected

dotStream is not code signed yet, so Windows SmartScreen shows "Windows protected your PC" on first run. Choose More info, then Run anyway.

This is not a judgement about the file — it is what Windows shows for any executable without a paid certificate behind it. Signing is on the roadmap; free certificates for open-source projects exist but take an application and a public release to qualify for.

Verify what you downloaded

Every release includes SHA256SUMS.txt. Check your download against it:

Get-FileHash .\dotStream-<version>-win-x64-setup.exe -Algorithm SHA256

Compare the result with the matching line in SHA256SUMS.txt. Builds are produced by GitHub Actions from a tagged commit, so the checksum can be traced back to the source that produced it.

Using it

Putting something on a key

Drag it. Everything you place is dragged from a list on the left onto a key — applications from the home page, actions from an app's own page. Deliberately not click-to-select-then-click-to-place: with fifteen keys already carrying something, a stray click that overwrites one is too easy and too quiet.

Drag a placed key onto another key to move it. Right-click any key for Clear, Rename and the widget options.

Pages

The home page is your applications. Press an app's key and it launches; press it again once it is running and its own page opens, holding the actions that belong to that program. Back returns home.

Pages can also open themselves. Follow the focused app (the toolbar button) opens a program's page when you switch to it, so alt-tabbing to Excel puts the Excel keys under your fingers. Navigating by hand pins the deck for thirty seconds so it does not move while you are using it.

What a key can do

Application	Launch it, and open its page
Hotkey	One combination — Ctrl+Shift+P
Sequence macro	Several in order — Alt, H, M, C for Merge and Centre. Ribbon commands are reachable this way without any application support
Text macro	Types a string. Quote a step in a sequence to type it mid-way
Run	A program or script, with arguments
Link	A URL or a file. steam://rungameid/892970 starts Valheim
Media	Play/pause, next, previous, volume, mute — with live state and album art
OBS Studio	Switch scene, start recording or streaming, mute a source
Discord	Mute, deafen, leave the voice channel
Widget	CPU, RAM or clock, on the three cells in column five

Volume keys repeat while held. Every key reports press and release separately, because the hardware does.

OBS Studio

Turn on Tools → WebSocket Server Settings → Enable WebSocket server in OBS. dotStream reads the port and password from OBS's own configuration, so there is nothing to copy across, and it connects on its own whenever OBS is running.

The OBS entry then appears in the action list, and disappears again when OBS closes. A key that talks to a program which is not running is a key that does nothing.

These keys light up. A scene key is lit while its scene is live, the record key while recording, a mute key while that source is muted. The lighting comes from OBS telling us it changed, not from what the key last did, so it stays right when you change something in OBS itself. That is the reason for going through the websocket instead of sending a keyboard shortcut.

A scene key shows the scene. OBS renders a thumbnail on request, so instead of a generic icon the key shows what that scene actually contains, refreshed every few seconds while the key is in view.

And an assistant can build the whole page for you. It asks OBS for your scenes and audio sources, proposes the keys, and you accept or reject on the deck without typing a single scene name.

Discord

Discord will ask your permission once. The first time dotStream connects, Discord shows an authorisation prompt with dotStream's name on it. Approve it and you will not see it again: a token is stored on your machine and renews itself.

That prompt is the security model, not an obstacle. dotStream can only reach the account of whoever said yes, on the machine where they said it. There is no server in the middle and no credential shipped in the download, because Discord supports PKCE for desktop applications. If a future version needs a permission it does not have yet, you will be asked again, once.

Nothing else to switch on. If Discord is running, dotStream connects to it.

The keys are lit from Discord, not from themselves. Mute yourself by clicking in Discord and the key follows. That is the whole reason this does not use the keyboard shortcuts, which fire and hope: a mute key that is wrong about whether your microphone is live is the one mistake this kind of software can make that you cannot undo afterwards.

Deafen turns off the microphone as well, because that is what Discord does. Both keys light up together.

Voice channel keys can fill themselves. A key can be bound to a named channel, or to "slot 1 of whichever server I am in", so a row of five follows you from server to server without building a page for each one. Each shows how many people are sitting in that channel. There is also a key for "the channel I am in right now", which is the only thing that works on servers that move you into a channel created on the fly.

This is aimed squarely at one screen. In fullscreen you cannot see Discord at all, and alt-tabbing out of a game risks a minimise or a stutter to find out something you could have read at a glance. The occupancy counts mean you can see where everyone is, and move to them, without leaving the game.

Camera and screen share are there too.

The authorisation is stored in %APPDATA%\dotStream\discord.dat, encrypted for your Windows account. It is the only credential dotStream keeps, and the only file here that is not plain readable JSON.

Which applications are listed

dotStream shows what Windows considers installed, filtered down to things that look like applications rather than uninstallers and help files. File → Select applications overrides that list entirely if the guess is wrong.

Steam games are added separately, because Steam stopped writing Start-menu entries and the shell genuinely cannot see them. They are read from Steam's own files and launched through steam://. If a game's icon looks low-resolution, browse your library in Steam once — that fills its artwork cache, and dotStream uses it.

If dotStream misidentifies which program is in front, View → What's in front? shows what it saw, and lets you correct it. The correction is remembered.

If the pictures look wrong

View → Calibrate cells. Several devices ship under this product name and this one measured 100×100, against notes claiming 85×85 and a manual recommending 126×126. If your icons come out cropped, offset, or leave a border of the previous image behind, drag the size slider until all four coloured bands of the measuring pattern look equally thick. Rotation is there for a panel mounted a different way.

Starting automatically

File → Start with Windows runs dotStream in the tray when you sign in. Windows offers no way to start an application when a USB device appears — not without enabling a log that records every USB event on the machine — so this comes at it from the other side: dotStream is already running, and it watches for the deck continuously. Plug in whenever; it wakes up.

Closing the window hides it to the tray, because the deck has to keep working. File → Exit quits properly, and leaves the deck dark.

Connecting an assistant

File → Agent bridge (MCP) starts the server, and Help → Instructions for your AI assistant opens the page to hand over. Paste the address to your assistant and it has everything it needs, including the tool list and how to write a key sequence.

tool	what it does
deck_propose_page	Offer a page of keys for you to accept, reject or defer
deck_set_key	Put one key in one place
deck_ask	Ask a question and wait for you to answer on a physical key
deck_notify	Put a message on an info cell
deck_status	What the deck is showing, and what is playing

It listens on 127.0.0.1 only.

Build & run

Needs the .NET 10 SDK.

dotnet build DotStream.slnx
dotnet run --project src\DotStream.App

Layout

src/
  DotStream.Core        Cell model, IDeckTransport, DeckController, IDeckAction
  DotStream.Rendering   CellRenderer, system metrics, info widgets
  DotStream.Icons       shell:AppsFolder enumeration, IShellItemImageFactory
  DotStream.Simulator   Virtual 6×3 deck + SimulatorTransport
  DotStream.App         WPF host
docs/
  PROTOCOL.md           Wire protocol, verified sources, open questions

Design decisions worth remembering

The side screen is three ordinary cells. Not an 854×480 panel. They are addressed with the same BAT command as the keys, at indices 16–18, and have no switch under them. This is what makes live info display cheap. See docs/PROTOCOL.md §5.

Rendering is device-agnostic. CellRenderer always produces upright images. Any device-specific orientation transform belongs in the transport, so the simulator and the real device share one rendering path.

Uploads are hash-gated. The firmware ACKs each image and corrupts the cell if a new upload starts early, so writes are serialised. That makes a redundant upload genuinely expensive, hence DeckController comparing pixel hashes and keeping only the newest pending image per cell.

Icons come from the shell, not from PE resources. ExtractAssociatedIcon caps at 32×32 and finds nothing for Store/MSIX apps. IShellItemImageFactory via shell:AppsFolder handles Win32, MSIX, shortcuts and folders uniformly, at 256×256 with a real alpha channel — and the same AppUserModelID launches all of them.

TextFormattingMode must be passed to the FormattedText constructor. TextOptions.SetTextFormattingMode on a DrawingVisual is a silent no-op — it is an attached property inherited by framework elements, while DrawingContext.DrawText uses whatever the FormattedText itself was built with. It looks like it works.

Label rendering is a control panel, not a constant. Font, weight, formatting mode, antialiasing and size are all switchable at runtime and saved to %APPDATA%\dotStream\text.json. There is no answer that can be found on a monitor: Display snaps stems to the pixel grid so stroke tops stay solid but quantises every advance width, Ideal keeps the spacing and lets the tops fray. Which reads better at 100×100, under a plastic cap, at a desk angle, is a judgement only the hardware can settle — which is why it is a slider rather than a decision taken here.

Shell icons need their row order checked. Shell handlers return both top-down and bottom-up DIBs. Copying the rows straight into a BitmapSource flips roughly half of all icons, and because it only shows on asymmetric artwork it is easy to ship without noticing. ShellInterop reads DIBSECTION.dsBmih.biHeight and flips when needed — BITMAP.bmHeight is always positive and tells you nothing.

Buttons are closures; profiles are declarations. A DeckButton holds Funcs, which cannot be serialised. Every button therefore carries a Tag — an InstalledApp or a catalogue action id — and that is what goes to disk. Closures are rebuilt on load from the app list and ActionCatalog, so a profile stays valid when an action's implementation changes.

An agent may draw on the deck; it may never say what a key does. The MCP tools set labels, colours and questions. Nothing binds a key to an action — those come only from the user's profile. A confused or compromised agent can therefore make the deck look wrong, but it cannot relabel "Pause music" into something that runs a program. The server binds 127.0.0.1 only and is off until switched on.

Animation is possible after all. This used to say the opposite, on the strength of an estimate that turned out to be ten times too pessimistic. Measured against the hardware: one cell takes 1.0 ms, a full eighteen-cell repaint takes 18 ms, and JPEG encoding adds 0.26 ms per cell. Thirty frames per second across the whole deck ran for six seconds without dropping one, and looked smooth.

Static icons that change on state is still the design point — a deck that moves all the time is a deck you stop reading. But the constraint was never real, so where motion earns its place it is available.

Licence and warranty

Apache License 2.0. See LICENSE and NOTICE.

dotStream is provided as is, without warranty of any kind. You use it at your own risk, and the author accepts no liability for any damage or loss arising from its use. It talks to hardware over a reverse-engineered protocol; that is the whole point of the project, and it is also the reason this paragraph is here.

Unofficial. Not affiliated with, authorised by, or endorsed by AJAZZ, Mirabox or Elgato.

Next

1. HID enumeration tool — identify what this unit actually reports
2. DIS → LIG 50 → CLE to prove the transport
3. Orientation brute-force, 8 variants of an asymmetric glyph
4. Persistence test: upload, unplug, replug — framebuffer or flash?
5. Media sessions + a Spotify page
6. Foreground-window hook and profile switching, with manual navigation pinning