Most AI video tools sell you credits. Solo Studio doesn't sell you anything after the download — you bring your own MuAPI key and pay MuAPI directly, at cost.It is a director's tool rather than a generator. The difference is continuity: keeping the same face across a dozen shots, the same prop in their hand and the same room around them, carrying the end of one clip into the start of the next, and knowing what a render costs before you commit to it.What's in itMovie Maker — build a cast once, then write @marcus walks into frame and get the same person, shot after shot. Each cast member holds up to four reference angles, a voice clip and a reference clip.People, props and places — a saved reference can be a person, an object or a location, and the app tells the model which it is. @marcus draws @sabre in @thebarn puts a character in a room holding a specific sword, instead of three people standing in an empty frame. Naming the kind is what makes that work: an unlabelled prop reads as a person to the model, and comes back as one.Build sheet — drop in one photo and it generates the missing views, chosen for what the thing actually is. A person gets a three-quarter, a side profile and a close-up; an object gets a three-quarter, a side elevation and a material detail; a location gets a wider establishing view, a reverse angle and a detail. That coverage is what holds a face, a shape or a room together once a shot is framed from anywhere other than straight on.Transform — feed in footage you already shot and describe what should change. Relight it, restyle it, replace the world around the subject.Extend — continue a finished clip past where it ends.Extract frame — grab any frame from a finished clip and drop it straight into the next shot as its opening image.First → Last — give it an opening and closing frame; it renders the motion between them.Plus Image, Video, Motion, Audio — score, sound effects, and speech in eighteen voices or a cloned one of your own — and Avatar.The price is on the buttonEvery render shows exactly what it will cost before you click, read live from MuAPI for the settings you have chosen — not a credit abstraction. Change the length, the resolution or the audio switch and the number moves with it. A 480p draft and a 4K master are the same two clicks apart, and you can see the difference in cents.No subscriptionRunway and Kling want $92–95 a month whether you shoot anything or not, and the credits they hand you burn on the takes you throw away as readily as the ones you keep. Solo Studio has no plan and no markup. You pay MuAPI directly, per render, and the exact figure is on the button before you click it. A month of light work is a few dollars. A month where you shoot nothing costs nothing at all.Auto-saveTurn it on and every render is written to disk the moment it finishes. AI providers expire their links after about thirty days; this is the setting that means a month of work is still there in October.What you get- Solo Studio.app — macOS, universal (Apple Silicon and Intel) - Solo Studio Setup.exe — Windows installer (64-bit and ARM) - Solo Studio.exe — Windows portable, runs without installing anything - SoloStudio.zip — the same app as a single web page. Works on Windows, Linux, or any Mac, in any browser. No install.What you need- A free account at muapi.ai, with credit added. Renders are billed to you directly, at MuAPI's cost. A still image is 3–5¢. A five-second clip runs $0.40 on the cheapest tier — fine for blocking out a shot, though it holds a specific face or prop loosely — $0.75 in the middle, and $1.25 on the tier worth using once continuity matters. 4K is $6.75. You see the exact figure on the button before every render. - macOS 10.13 or later, or Windows 10 or later, for the app. Any modern browser for the web version. - A desktop or laptop. This is a studio, not a phone app: the shot rail, the cast panel and the settings all sit side by side, and renders are written to a folder on your machine. It is not built for phones or tablets.Before you buy- This app is not code-signed. Both systems will warn you the first time. On macOS, right-click the app and choose Open. On Windows you get a full-screen “Windows protected your PC” block with no visible Run button — click More info, then Run anyway; some antivirus also quarantines unsigned installers, so if the file disappears, that is why. Standard for indie tools sold outside an app store. - You supply the API key. There is no subscription and nothing is marked up, but there is also no free credit included. - Updates are re-downloads from this page, not automatic.