# Octet Mobile SDK

Proof of location for iOS and Android apps.

## What the SDK does

Your app calls `sdk.loc.isWithin(region: ...)` and gets back an [`OctetVerdict`](/docs/v3.0/api-reference/octet-verdict/). Its result is `YES` (the device is inside the region), `NO` (the device is outside it), or `INDETERMINATE` (the SDK cannot answer, and a reason code says why). A `YES` or `NO` carries a signed proof that anyone can verify offline.

## Starting points

<div class="docs-doors" markdown="0">
<a class="docs-door" href="/docs/mobile/getting-started/ios-quickstart/"><span class="dd-t">iOS Quick Start</span><span class="dd-d">Install with Swift Package Manager and get a first verdict</span></a>
<a class="docs-door" href="/docs/mobile/getting-started/android-quickstart/"><span class="dd-t">Android Quick Start</span><span class="dd-d">Install from Maven and get a first verdict</span></a>
<a class="docs-door" href="/docs/mobile/concepts/proof-of-location/"><span class="dd-t">Proof of Location</span><span class="dd-d">What a proof records and how the SDK produces it</span></a>
<a class="docs-door" href="https://octetproof.com/product/"><span class="dd-t">What users see</span><span class="dd-d">What the person sees in your app while the SDK runs</span></a>
<a class="docs-door" href="/docs/mobile/concepts/on-device-verification/"><span class="dd-t">On-device Verification</span><span class="dd-d">Verify a proof on the device, offline, with <code>Octet.verify</code></span></a>
<a class="docs-door" href="/docs/mobile/api-reference/overview/"><span class="dd-t">API Reference</span><span class="dd-d">One page per symbol, Swift and Kotlin side by side</span></a>
<a class="docs-door" href="/docs/mobile/getting-started/upgrading-from-2x/"><span class="dd-t">Upgrading from 2.x</span><span class="dd-d">Changes from 2.0 to 3.0, breaking changes first</span></a>
<a class="docs-door" href="/docs/mobile/getting-started/migrating-from-1x/"><span class="dd-t">Migrating from 1.x</span><span class="dd-d">Changes from 1.x to 2.0, breaking changes first</span></a>
<a class="docs-door" href="/docs/mobile/troubleshooting/faq/"><span class="dd-t">Troubleshooting &amp; FAQ</span><span class="dd-d">Indexed by what you see in <code>verdict.reason</code> or <code>LicenseError</code></span></a>
</div>

## Access

Create an account and register your app once at [sdk.octetproof.com/signup](https://sdk.octetproof.com/signup) (see [Prerequisites](/docs/v3.0/getting-started/prerequisites/)). Use of the SDK is governed by the [Octet SDK License Agreement](https://octetproof.com/terms/mobile/). Pricing is at [octetproof.com/pricing](https://octetproof.com/pricing).

:::note[SDK 3.0.0]

These docs describe SDK 3.0.0, a major release. [What's new in 3.0](/docs/v3.0/whats-new/) lists the changes from 2.0. The 2.0 docs stay at [/docs/v2.0/](/docs/v2.0/) and the 1.x docs at [/docs/v1.2/](/docs/v1.2/).

:::