React Native PrismSDK Capture Wrapper Guide

This guide explains how to build a React Native native module - PrismCapture - that wraps the body-scan capture experience only of PrismSDK for both iOS and Android behind one unified JS/TS API. The module presents the full-screen capture UX, receives the output zip, and performs a direct PUT upload to an S3 presigned URL that your backend obtains from the Prism API. No Prism API credentials are needed on the device; all REST calls (user management, scan records, measurements, health reports) remain on the backend and are out of scope for this module.

Scope - What This Wraps / What It Doesn't

Wraps:

Full-screen capture UX: volume check → (face guidance, iOS only) → device leveling → body positioning → posing → recording → processing → optional review → finished.
Output: a .zip file written to local storage.
Zip upload: a direct HTTP PUT to an S3 presigned URL (Content-Type: application/zip).

Does NOT wrap:

The Prism REST API (user creation, scan lifecycle, measurements, health reports). These live on your backend server.
Any authentication or API key management. Capture requires no PrismSDK-Info.plist on iOS and no API credentials on Android.

Unified Architecture

JS Layer
  └── NativeModules.PrismCapture   ← one JS surface
        ├── iOS: PrismCapture.swift / PrismCapture.m  (RCTEventEmitter)
        │         presents PrismSessionViewController (UIKit) or UIHostingController<PrismSessionView>
        │         FileUploader (PrismLink) for background S3 PUT
        └── Android: PrismCaptureModule.kt  (ReactContextBaseJavaModule)
                      launches PrismCaptureActivity (ComponentActivity + Compose)
                      PrismSessionView Composable wraps PrismSession controller
                      Ktor client for S3 PUT

New Architecture note: On RN New Architecture (Fabric / JSI), this module becomes a TurboModule. The JS surface - method names, event names, payload shapes - is identical. The bridge registration code (.m file on iOS, Package on Android) is the only mechanical change; swap RCT_EXTERN_MODULE for the codegen spec and register via ReactPackageTurboModuleManagerDelegate on iOS, and implement the generated NativePrismCaptureTurboModule spec on Android.

Module Contract

Methods

RN Method	What it does	Platform notes
`startCaptureSession(options?)`	Presents the full-screen capture flow.	Both platforms
`dismissCaptureSession()`	Programmatically dismisses the capture UI.	Both platforms
`uploadCapture(filePath, presignedUrl)`	Uploads the zip at `filePath` via HTTP PUT to `presignedUrl`.	Both; see platform differences
`setupUploader()`	Resumes interrupted background uploads from a previous app session.	iOS only. On Android this is a documented no-op.

Events

RN Event	When it fires	Payload
`onCaptureComplete`	Zip is ready on disk.	`{ archivePath: string }`
`onStatusChange`	Capture state machine transitions.	`{ status: string, error?: string }`
`onDismiss`	Capture UI is dismissed (user or programmatic).	`{}`
`onUploadProgress`	Upload bytes transferred.	`{ progress: number }` (0.0–1.0)
`onUploadComplete`	Upload finished (success or failure).	`{ success: boolean }`