> ## Documentation Index
> Fetch the complete documentation index at: https://mahmoud-b28887f9.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# KPdfSource: specify where KPDF should load the PDF from

> KPdfSource is a sealed interface with three variants — Url, Bytes, and Base64 — that tells KPDF where to load the document from and drives caching identity.

`KPdfSource` is a sealed interface with three variants: `Url`, `Bytes`, and `Base64`. You pass a `KPdfSource` value to `KPdfViewerState.open()` or to `KPdf.viewerState()` to tell the SDK where to load the document from. Each variant is a data class, so equality and caching are based on the field values you provide.

## KPdfSource.Url

Use `KPdfSource.Url` when your PDF is hosted at a remote HTTPS address. The SDK fetches the document through its internal source pipeline. Because HTTP headers can affect the response — for example, authentication tokens or content-negotiation directives — headers are part of the source identity: two `Url` instances with identical URLs but different headers are treated as distinct sources.

<ParamField path="url" type="String" required>
  The HTTPS URL of the remote PDF document.
</ParamField>

<ParamField path="headers" type="Map<String, String>" default="emptyMap()">
  Custom HTTP request headers to include when fetching the PDF. Headers are part of the source identity — changing a header value produces a distinct source that bypasses the previous cache entry.
</ParamField>

<Note>
  Because `headers` contribute to source identity, supplying a new `Authorization` value or any other changed header causes the SDK to treat the request as a new source and fetch the document again rather than serving the cached copy.
</Note>

```kotlin theme={null}
// Public URL with no extra headers
val publicSource = KPdfSource.Url(
    url = "https://example.com/document.pdf"
)

// Authenticated URL — different token = different cached source
val authenticatedSource = KPdfSource.Url(
    url = "https://api.example.com/reports/q1.pdf",
    headers = mapOf("Authorization" to "Bearer eyJhbGci...")
)
```

## KPdfSource.Bytes

Use `KPdfSource.Bytes` when you have already loaded the raw PDF bytes in your application — for example, after reading a file from disk or downloading it yourself. The SDK does not perform any network request; it reads directly from the `ByteArray` you provide.

`KPdfSource.Bytes` implements structural equality via `contentEquals`, so two instances wrapping byte-for-byte identical arrays are considered equal.

<ParamField path="data" type="ByteArray" required>
  The complete, raw bytes of a valid PDF document.
</ParamField>

```kotlin theme={null}
// Read bytes from a local file (platform-specific I/O shown for illustration)
val pdfBytes: ByteArray = File("invoice.pdf").readBytes()

val bytesSource = KPdfSource.Bytes(data = pdfBytes)
```

## KPdfSource.Base64

Use `KPdfSource.Base64` when your PDF is delivered as a Base64-encoded string. The SDK accepts both a raw Base64 string and a data URL of the form `data:application/pdf;base64,<encoded>`.

<ParamField path="value" type="String" required>
  A raw Base64-encoded PDF string or a full data URL in the format `data:application/pdf;base64,<encoded>`. Both forms are accepted.
</ParamField>

```kotlin theme={null}
// Raw Base64 string
val rawBase64Source = KPdfSource.Base64(
    value = "JVBERi0xLjQKJ..."
)

// Data URL form
val dataUrlSource = KPdfSource.Base64(
    value = "data:application/pdf;base64,JVBERi0xLjQKJ..."
)
```