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Connect to existing AWS resources

Amplify client libraries can be used independently without the Amplify backend workflow. If you've provisioned AWS resources with CDK, Terraform, CloudFormation, or the AWS Console, you can connect Amplify libraries directly to those resources.

This means you can adopt Amplify's client libraries for authentication, data, storage, and more — while keeping full control over your infrastructure.

When to use this approach

You already have AWS resources provisioned with CDK, Terraform, or CloudFormation
You want to use Amplify client libraries without adopting the Amplify backend (ampx) workflow
You need to connect to shared infrastructure managed by a platform team
You want programmatic control over configuration for testing or environment switching

How it works

There are two ways to configure Amplify client libraries with your own resources:

Option 1: Manual `amplify_outputs.json`

Create an amplify_outputs.json file in your Xcode project. See the full specification for all supported fields.

amplify_outputs.json
  "version": "1",
  "auth": {
    "aws_region": "us-east-1",
    "user_pool_id": "us-east-1_abc123",
    "user_pool_client_id": "abcdef123456",
    "identity_pool_id": "us-east-1:11111111-2222-3333-4444-555555555555"

Then configure Amplify as usual:

try Amplify.add(plugin: AWSCognitoAuthPlugin())
try Amplify.configure(with: .amplifyOutputs)

Option 2: Programmatic configuration with `AmplifyOutputsData`

Build the configuration in code without any JSON files:

import Amplify
import AWSCognitoAuthPlugin
let config = AmplifyOutputsData(
    auth: .init(
        awsRegion: "us-east-1",
        userPoolId: "us-east-1_abc123",
        userPoolClientId: "abcdef123456"
try Amplify.add(plugin: AWSCognitoAuthPlugin())
try Amplify.configure(config)

This approach is ideal for:

Unit testing — Configure Amplify without bundling JSON files
Environment switching — Build different configurations for dev/staging/prod
Dynamic configuration — Fetch configuration from a remote source at runtime

Configure Auth (Amazon Cognito)

Connect to an existing Cognito User Pool and Identity Pool.

let config = AmplifyOutputsData(
    auth: .init(
        awsRegion: "us-east-1",
        userPoolId: "us-east-1_abc123",
        userPoolClientId: "abcdef123456",
        identityPoolId: "us-east-1:11111111-2222-3333-4444-555555555555",
        passwordPolicy: .init(
            minLength: 8,
            requireNumbers: true,
            requireLowercase: true,
            requireUppercase: true,
            requireSymbols: false
        oauth: .init(
            identityProviders: ["GOOGLE", "SIGN_IN_WITH_APPLE"],
            domain: "myapp.auth.us-east-1.amazoncognito.com",
            scopes: ["openid", "email", "profile"],
            redirectSignInUri: ["myapp://callback"],
            redirectSignOutUri: ["myapp://signout"],
            responseType: "code"
        standardRequiredAttributes: [.email],
        usernameAttributes: [.email],
        userVerificationTypes: [.email],
        unauthenticatedIdentitiesEnabled: true,
        mfaConfiguration: "OPTIONAL",
        mfaMethods: ["SMS", "TOTP"]
try Amplify.add(plugin: AWSCognitoAuthPlugin())
try Amplify.configure(config)

Auth required fields

Field	Required	Description
`awsRegion`	Yes	AWS region (e.g. `us-east-1`)
`userPoolId`	Yes	Cognito User Pool ID
`userPoolClientId`	Yes	Cognito app client ID
`identityPoolId`	No	Cognito Identity Pool ID (needed for guest access and IAM-based auth)
`passwordPolicy`	No	Password requirements (min length, character types)
`oauth`	No	OAuth/Hosted UI configuration (social sign-in)
`mfaConfiguration`	No	MFA mode: `NONE`, `OPTIONAL`, or `REQUIRED`
`mfaMethods`	No	MFA types: `SMS`, `TOTP`

Configure Data (AWS AppSync)

Connect to an existing AppSync GraphQL API.

let config = AmplifyOutputsData(
    data: .init(
        awsRegion: "us-east-1",
        url: "https://abc123.appsync-api.us-east-1.amazonaws.com/graphql",
        apiKey: "da2-abcdefghijklmno",
        defaultAuthorizationType: .apiKey,
        authorizationTypes: [.apiKey, .amazonCognitoUserPools]
try Amplify.add(plugin: AWSAPIPlugin())
try Amplify.configure(config)

Data required fields

Field	Required	Description
`awsRegion`	Yes	AWS region
`url`	Yes	AppSync GraphQL endpoint URL
`defaultAuthorizationType`	Yes	Default auth mode: `API_KEY`, `AMAZON_COGNITO_USER_POOLS`, `AWS_IAM`, or `OPENID_CONNECT`
`authorizationTypes`	Yes	All supported auth modes
`apiKey`	No	Required if using `API_KEY` auth

Configure Storage (Amazon S3)

Connect to an existing S3 bucket.

let config = AmplifyOutputsData(
    auth: .init(
        awsRegion: "us-east-1",
        userPoolId: "us-east-1_abc123",
        userPoolClientId: "abcdef123456",
        identityPoolId: "us-east-1:11111111-2222-3333-4444-555555555555"
    storage: .init(
        awsRegion: "us-east-1",
        bucketName: "my-app-bucket"
try Amplify.add(plugin: AWSCognitoAuthPlugin())
try Amplify.add(plugin: AWSS3StoragePlugin())
try Amplify.configure(config)

Multiple buckets

let config = AmplifyOutputsData(
    storage: .init(
        awsRegion: "us-east-1",
        bucketName: "primary-bucket",
        buckets: [
            .init(name: "media", bucketName: "my-media-bucket", awsRegion: "us-east-1"),
            .init(name: "logs", bucketName: "my-logs-bucket", awsRegion: "us-west-2")

Storage requires Auth (Cognito Identity Pool) for authorization. Always configure Auth alongside Storage.

Storage required fields

Field	Required	Description
`awsRegion`	Yes	AWS region
`bucketName`	Yes	Default S3 bucket name
`buckets`	No	Additional named buckets for multi-bucket setups

Configure Analytics (Amazon Pinpoint)

Connect to an existing Pinpoint application.

let config = AmplifyOutputsData(
    analytics: .init(
        amazonPinpoint: .init(
            awsRegion: "us-east-1",
            appId: "abc123def456"
try Amplify.add(plugin: AWSPinpointAnalyticsPlugin())
try Amplify.configure(config)

Configure Geo (Amazon Location Service)

Connect to existing Location Service resources.

let config = AmplifyOutputsData(
    geo: .init(
        awsRegion: "us-east-1",
        maps: .init(
            items: ["myMap": .init(style: "VectorEsriStreets")],
            default: "myMap"
        searchIndices: .init(
            items: ["myPlaceIndex"],
            default: "myPlaceIndex"
        geofenceCollections: .init(
            items: ["myGeofenceCollection"],
            default: "myGeofenceCollection"
try Amplify.add(plugin: AWSLocationGeoPlugin())
try Amplify.configure(config)

Configure Notifications (Push)

Connect to an existing Pinpoint application for push notifications.

let config = AmplifyOutputsData(
    notifications: .init(
        awsRegion: "us-east-1",
        amazonPinpointAppId: "abc123def456",
        channels: [.apns, .fcm, .inAppMessaging]
try Amplify.add(plugin: AWSPinpointPushNotificationsPlugin())
try Amplify.configure(config)

Multi-category configuration

You can configure multiple services together. This example sets up Auth, Data, and Storage in a single configuration.

let config = AmplifyOutputsData(
    auth: .init(
        awsRegion: "us-east-1",
        userPoolId: "us-east-1_abc123",
        userPoolClientId: "abcdef123456",
        identityPoolId: "us-east-1:11111111-2222-3333-4444-555555555555"
    data: .init(
        awsRegion: "us-east-1",
        url: "https://abc123.appsync-api.us-east-1.amazonaws.com/graphql",
        defaultAuthorizationType: .amazonCognitoUserPools,
        authorizationTypes: [.amazonCognitoUserPools, .awsIAM]
    storage: .init(
        awsRegion: "us-east-1",
        bucketName: "my-app-bucket"
try Amplify.add(plugin: AWSCognitoAuthPlugin())
try Amplify.add(plugin: AWSAPIPlugin())
try Amplify.add(plugin: AWSS3StoragePlugin())
try Amplify.configure(config)

Inspecting resolved configuration

You can inspect the configuration resolved from amplify_outputs.json:

let outputs = try AmplifyOutputs.amplifyOutputs.resolveConfiguration()
if let auth = outputs.auth {
    print("User Pool ID: \(auth.userPoolId)")
    print("Region: \(auth.awsRegion)")
    print("Identity Pool: \(auth.identityPoolId ?? "none")")
if let storage = outputs.storage {
    print("Bucket: \(storage.bucketName)")
    print("Additional buckets: \(storage.buckets?.count ?? 0)")
if let data = outputs.data {
    print("GraphQL endpoint: \(data.url)")
    print("Default auth: \(data.defaultAuthorizationType)")

Environment-specific configuration

Switch between dev, staging, and production without separate JSON files:

let region: String
let userPoolId: String
let clientId: String
switch environment {
    region = "us-east-1"
    userPoolId = "us-east-1_dev123"
    clientId = "devClient123"
case .staging:
    region = "us-west-2"
    userPoolId = "us-west-2_staging456"
    clientId = "stagingClient456"
case .prod:
    region = "us-east-1"
    userPoolId = "us-east-1_prod789"
    clientId = "prodClient789"
let config = AmplifyOutputsData(
    auth: .init(
        awsRegion: region,
        userPoolId: userPoolId,
        userPoolClientId: clientId
try Amplify.configure(config)

`amplify_outputs.json` schema reference

For the full schema of all supported configuration fields, see the amplify_outputs.json reference.