Merge pull request #3 from passageidentity/PSG-4526-readme

Setup readme

Author: rickycpadilla

README.md

@@ -1,22 +1,114 @@
 # passage-flex-react-native
 
-Native passkey authentication for your React Native and Expo apps.
+Passkey Flex provides passkey authentication support to existing authentication systems. It handles the hard parts of incorporating native passkey APIs and provides a simple, clean solution to take your authentication to the next level.
+
+Use the `passage-flex-react-native` SDK to implement Passkey Flex in your React Native app to use passkeys to register and authenticate, or as added security on secure user actions.
+
+For full documentation, including setting up a backend SDK, visit the [Passkey Flex documentation here](https://docs-v2.passage.id/flex).
+
+## Prerequisites
+
+### A Passkey Flex app
+
+1. Create a Passkey Flex app in the Passage Console at https://console.passage.id 
+2. Add an Android and/or iOS app in the Native Apps section
+3. When you add your Native App info, you can generate the associated domain file for that app if you haven’t already created it yourself, as shown below:
+![Passage Native Apps screenshot](https://docs-v2.passage.id/_next/image?url=%2Fimages%2Fdownload-config.png&w=3840&q=75)
+
+
+### Hosted associated domains files
+
+In order for passkeys to work, you’ll need to associate your native app(s) with the public web domain you assigned to your Passkey Flex app.
+
+Android requires an `assetlinks.json` file configured and hosted (learn more [here](https://developer.android.com/identity/sign-in/credential-manager#add-support-dal)).
+
+Apple requires an `apple-app-site-association` file configured and hosted (learn more [here](https://developer.apple.com/documentation/Xcode/supporting-associated-domains)).
 
 ## Installation
 
-```sh
-npm install passage-flex-react-native
+Install this package using npm:
+
+```
+npm i --save @passageidentity/passage-flex-react-native
 ```
 
+## App configuration
+
+### Expo
+
+- Add plugin in app.json
+    
+    ```json
+    "plugins": [
+          "@passageidentity/passage-flex-react-native",
+          // ...
+    ]
+    ```
+    
+- Add `ASSOCIATED_DOMAIN` value to `.env` (in your app root)
+    
+    ```
+    ASSOCIATED_DOMAIN=example.com
+    ```
+    
+- Run `npx expo prebuild`
+
+### Bare React Native
+
+See our [Passkey Complete documentation](https://docs.passage.id/mobile/cross-platform/cross-platform-passkey-configuration) for setting up a React Native app for passkeys and Passage.
+
 ## Usage
 
+Import PassageFlex:
+
+```tsx
+import { PassageFlex } from '@passageidentity/passage-flex-react-native';
+```
+
+Initialize a Passage Flex instance using your `appId` found in [Passage Console](https://console.passage.id/):
+
+```tsx
+const passageFlex = new PassageFlex('YOUR_APP_ID');
+```
+
+### passageFlex.passkey.register
+
+To register a new user passkey, use the `passageFlex.passkey.register` method.
+
+Example:
+
+```tsx
+const onPressRegister = async () => {
+	// 1. Get transaction id string from your backend.
+	const transactionId = await getRegisterTransactionId("newuser@email.com");
+	// 2. Prompt user to create a passkey and get a Passage nonce value on success.
+  const nonce = await passageFlex.passkey.register(transactionId);
+  // 3. You can send this nonce to your backend to complete user registration.
+};
+```
+
+### passageFlex.passkey.authenticate
+
+To log in a user using a passkey, use the `passageFlex.passkey.authenticate` method.
+
+Example:
+
+```tsx
+const onPressLogIn = async () => {
+	// 1. Get transaction id string from your backend.
+	const transactionId = await getLogInTransactionId("existinguser@email.com");
+	// 2. Prompt user to create a passkey and get a Passage nonce value on success.
+  const nonce = await passageFlex.passkey.authenticate(transactionId);
+  // 3. You can send this nonce to your backend to complete user authentication.
+};
+```
 
-```js
-import { multiply } from 'passage-flex-react-native';
+### passageFlex.passkey.isSupported
 
-// ...
+You can check if a user’s device supports passkeys by calling `passageFlex.passkey.isSupported`:
 
-const result = await multiply(3, 7);
+```tsx
+const deviceSupportsPasskeys = passageFlex.passkey.isSupported();
 ```