generated: '2026-07-18'
method: searched
source: https://docs.castle.io/docs/sdk-browser + https://docs.castle.io/docs/sdk-mobile
description: >-
  Client-side, embeddable SDK components that collect the device fingerprint and
  generate the short-lived request token consumed by the backend Risk/Filter
  APIs. Distinct from the server-side SDKs in packages/.
families:
- name: Browser SDK
  description: JavaScript client-side SDK that fingerprints the browser and produces a request token via castle.createRequestToken().
  loader: "@castleio/castle-js"
  install: npm install @castleio/castle-js
  docs: https://docs.castle.io/docs/sdk-browser
- name: Mobile SDK (iOS)
  description: Native iOS SDK for device fingerprinting and user-activity monitoring.
  loader: Castle (CocoaPods / Swift Package)
  docs: https://docs.castle.io/docs/sdk-mobile
- name: Mobile SDK (Android)
  description: Native Android SDK for device fingerprinting and user-activity monitoring.
  loader: castle-android
  docs: https://docs.castle.io/docs/sdk-mobile
- name: React Native SDK
  description: React Native wrapper over the native mobile SDKs.
  loader: "@castleio/react-native-castle"
  docs: https://docs.castle.io/docs/sdk-mobile