# Credits and billing

How credits work in the app and through the API: what uses them, how a video and its voiceover are priced, what plans include, adding credits, and what comes back.

## Credits

Everything 10xvid makes uses credits: reading a site, building a Format DNA, updating it, studying a reference video, and each video and image in each shape. Styles filmed by video models, and skills such as Anime, also use credits for the models that draw, film and score them, by what those models really take. Settings in the app shows what is left and what your credits went on.

A video is priced by the second, in each shape, at its engine's price: a 30 second video costs six times a 5 second one. Its voiceover is priced on its own, by the characters it speaks, and its music by its seconds, each once for the video in all its shapes. A Motion V1 Flash video can be made with no music, and then its music is not charged. Everything else is charged what it really used: a long site takes more work than a short one, so it uses more credits. When something starts, its price is set aside; when it is done, what was not used comes back, or the difference is taken, never more than you have left. [API pricing](/docs/api/pricing) has the details.

A plan gives credits every month. The free first ad gives its credits once. Unused plan credits do not roll over to the next month.

## Plans

Each plan includes a number of credits a month. The [pricing page](/pricing) shows the plans and what they include, and the API side of Subscription shows what each plan's credits make through the API.

## Adding credits

- **Add credits** on the API side of Subscription, at $1 for 1,000. Once your plan's credits run out, they pay for what you make in the app and through the API alike, and they stay until you use them.
- **Auto Top Up** adds credits from your saved card when they drop below an amount you choose, up to a monthly cap you set.

## Through the API

An API call is paid from your plan's credits first, the same credits the app spends, then from the credits you added. See [API pricing](/docs/api/pricing).

## What comes back

You pay only for what is delivered. Credits for anything that is not delivered come back by themselves, to where they came from.