Build Mode
What actually happens when fluos builds your video.
Build mode applies changes to your composition. It is the default, and it is where every video is actually made.
What happens after you hit send
- A sandbox starts. Every project gets an isolated environment where the composition is written and run. On a cold project this is the "Booting" state in the preview.
- The agent works. It reads the relevant skills, pulls in any attachments or library assets, writes the composition, and generates narration, music, or sound effects if the video needs them.
- fluos checks its own work. The build is validated and rendered frame-by-frame to measure whether things actually move. Problems get repaired automatically, up to a handful of passes.
- The preview updates. The status chip flips to Live and you can play it.
A build is meaningfully slower than a chat reply because all four of those steps are real. Long, narrated, multi-scene videos take the longest.
The tools the agent uses
You do not call these directly — you ask for an outcome and fluos picks the tool. Knowing they exist helps you ask for the right thing.
| Capability | What to ask for | Limits per build |
|---|---|---|
| Narration, music, sound effects | "Add a calm voiceover", "put a subtle music bed under it" | — |
| Word-level captions | "Add captions synced to the voiceover" | — |
| Review your uploaded footage | "Which parts of this clip are usable?" | 10 reviews |
| Cut a segment from your footage | "Use the 0:12–0:18 part of that clip" | 8 cuts, 60s max each |
| Browse the workspace library | "Use our logo from the library" | Up to 80 assets listed |
| Read a spreadsheet | "Chart the revenue column" | — |
| Web research | "Match the style of stripe.com" | — |
| AI video clips (MAX, Pro) | "Generate a b-roll shot of a city at dusk" | 2 clips, 5s max each |
| AI images (MAX, Pro) | "Generate an abstract gradient background" | 6 images |
The per-build caps exist so one slow generation cannot starve the rest of the build. If you need more, split the work across follow-ups.
Quality gates
fluos measures its own motion rather than trusting the model's opinion of it. Frames are sampled and compared, so a scene that "fades in and freezes" is detected as static even if the code looks animated.
For narrated multi-scene explainers, that check can block a build: if scenes are still frozen after the automatic repair passes, fluos declines to publish that version and tells you so, rather than handing you a slideshow with a voiceover over it. Ask it to retry and it reworks the flagged scenes.
Softer findings — pacing notes, judgment calls — show as a dismissible Motion quality notes banner and never block. A validated build is never thrown away over an opinion.
Free plan builds
On the free plan you get one build per day, reset at midnight UTC. Questions, brainstorming, and Plan mode do not count — only messages that actually commission video work. The composer shows how many you have left.
When you are out, you get a clear message and the option to upgrade. See Plans and Credits.
If a build takes too long
Builds have a time budget. If a composition is too heavy to finish inside it, the run stops with an explanation rather than hanging forever. The usual causes are long embedded video and very high frame counts — shorten the footage segment or reduce the scope and try again.