# Managing Assets
Learn how dotlottie-io handles image, font, and audio assets, including automatic filename deduplication.

# Managing Assets

Images, fonts, and audio are stored as raw binary files inside the `.lottie` archive. `dotlottie-io` exposes an identical three-method pattern for each asset type: `add*`, `get*`, and `*Filenames`.

```javascript
dotlottie.addImage(filename, data); // Buffer → returns stored filename (string)
dotlottie.getImage(filename); // → Buffer | null
dotlottie.imageFilenames(); // → string[]

dotlottie.addFont(filename, data);
dotlottie.getFont(filename);
dotlottie.fontFilenames();

dotlottie.addAudio(filename, data);
dotlottie.getAudio(filename);
dotlottie.audioFilenames();
```

## Two ways assets end up in a package

1. **Implicitly**, via [`addAnimation`](/docs/tools/dotlottie-io/core-concepts/animations) — assets embedded as base64 in the Lottie JSON are extracted automatically.
2. **Explicitly**, via `addImage`/`addFont`/`addAudio` — attach a standalone asset file directly, independent of any single animation's embedded data.

## Audio format restriction

Only `.mp3` is accepted for audio. Calling `addAudio` with any other extension throws `InvalidAudioFormat`.

## Filename deduplication

Asset filenames must be unique within the package. Rather than throwing on a collision, `add*` methods **rename** the incoming asset and return the actual stored name:

```javascript
const first = dl.addImage("logo.png", data); // → 'logo.png'
const second = dl.addImage("logo.png", data); // → 'logo_1.png'
const third = dl.addImage("logo.png", data); // → 'logo_2.png'
```

The rename pattern is `{stem}_{n}.{ext}`, incrementing `n` until a free name is found. **Always use the returned string** — not the name you passed in — as the key for later `getImage`/`getFont`/`getAudio` calls.

This same renaming logic is what [`MergeStrategy.Rename`](/docs/tools/dotlottie-io/api/dotlottie-merger-class#mergestrategy) uses when merging packages, and what the automatic extraction in `addAnimation` uses for embedded assets.

Next up: [Managing Themes](/docs/tools/dotlottie-io/core-concepts/themes)