#Assets

Your Asset library holds the files your games use. Assets belong to your workspace, so every project can use them.

#Upload an asset

Open Upload asset (or Asset library → Upload asset).
Drop the files for one asset, or browse for them. The kind is detected from the set.
Check the name and the alias prefix; the form shows the aliases it creates.
Optionally pick a requirement to check against, and a project to add it to.
Tick I have the right to use these files in my games.
Choose Add to library. The files upload straight to storage, then the server checks them and shows any warnings.

If the files can't be used (for example an atlas page is missing), nothing is kept and the message says why.

#Upload rights

Every upload (assets, components, and uploads from the editor) asks you to confirm that you have the right to use the files. The confirmation is kept with each asset: who confirmed it, when, and which wording they saw. Once you've ticked it, it stays ticked on every upload screen until you close the browser. If the wording changes, you're asked again. An upload without it is refused.

#Asset kinds

Kind	Files	Aliases
Image	one PNG, JPG, WebP, GIF, AVIF or SVG	`prefix`
Spritesheet	`.json` (TexturePacker) plus its page images	`prefix`
Spine	`.json` or `.skel`, `.atlas`, and the atlas pages	`prefixSkeleton`, `prefixAtlas`
Bitmap font	`.fnt` (text or XML) plus its page images	`prefix`
Video	WebM or MP4	`prefix`
Audio	WAV, MP3, OGG, M4A, AAC, Opus or FLAC	`prefix`
Font	one TTF, OTF, WOFF or WOFF2	`prefix`

#Fonts

Upload a font file (TTF, OTF, WOFF or WOFF2) like any other asset. When the upload finishes, the font is checked by its contents, not its extension, and its family name (and style, such as Bold) is read from the font itself and shown in the library. The preview draws a sample line in the font. Collections (.ttc) aren't supported; upload each font on its own.

Text uses a font by its alias, and builds include the font file with the game. Fonts are different from bitmap fonts: a bitmap font is a .fnt with images and draws only the characters it has, while a font file scales to any size and covers its whole character set.

Aliases are unique in your library. Scenes refer to assets by alias, so changing a file means uploading it under the same alias after deleting the old asset.

#Audio

Upload audio in any common format. Your original is kept in the library, and Oxinator makes two game-ready copies of it a moment after the upload:

Opus in WebM, what games play. It's about a third smaller than MP3 at the same quality.
AAC (.m4a), a fallback that only devices without Opus download, mainly older iPhones and iPads. You never manage it.

How a file is encoded depends on its length:

Sound effects (up to 15 seconds) become mono, 48 kHz, around 64 kbps, with silence trimmed from the start and the end.
Longer files are treated as music: stereo, around 112–128 kbps, and they stream while the game plays.
Loudness is evened out (about −16 LUFS), so sounds play at similar volumes.

The asset's details show whether the copies are ready. Builds ship only these copies, never your original, and the game-size readout counts them: sound effects in the initial download, music in the total only. If you build before the copies are ready, the build says so; build again a minute later. If a file can't be converted, the build names it; upload it again in another format.

Components can bring their own sounds: put the audio files in the package and the sounds, pools, chains and cues in component.json (see Components).

#Preview

Choose Preview on a card. Spine animations play live, with the animation list, play and pause, loop, speed and skins. Bitmap fonts render a sample of their own characters. Images, spritesheets, video and audio use the browser's players.

#Requirements

A requirement is a set of checks an asset should pass, such as "Slot game logo": a Spine skeleton with the animations intro and loop, the slot numbers_holder, and under 2 MB. Templates use requirements to describe the assets you swap in. Pick one when uploading, or in the preview, to see which checks pass. A failed check doesn't stop the upload.

#Export Spine 4.3

The engine runs Spine 4.3. Skeletons exported from another version get a warning ("Exported with Spine 4.1.24; the runtime is 4.3") and may not play correctly.

Open the project in Spine 4.3 or later.
Export → JSON (or binary), with Pack set to create an atlas.
Upload the .json or .skel, the .atlas and every page image together.

#Delete an asset

Open its preview and choose Delete asset…. An asset a project still uses can't be deleted; the dialog names the projects. Deleting frees its storage.

#Storage

The meter under the library shows assets and builds against your plan's quota. See Plans and billing.