The Amplify client libraries and UI components work against AWS resources created any way you like: CDK, Terraform or the console. How to point them at an existing Cognito user pool, AppSync API or S3 bucket, what you gain (sign-in screens, token refresh, signed uploads) and what you give up.
Teams often reject Amplify because they do not want it managing their backend, and then hand-write sign-in flows, token refresh and S3 upload signing. The libraries are separable. You can keep infrastructure in CDK or Terraform and use Amplify only on the client.
Auth: sign-up, sign-in (including passwordless and passkeys), MFA, token storage and refresh against an existing Cognito user pool, and the Authenticator UI if you want it.
API: GraphQL calls and subscriptions against an existing AppSync API, or signed REST calls.
Storage: uploads and downloads to an existing S3 bucket with credentials from a Cognito identity pool, and the Storage Browser component.
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Create the resources in your own IaC: user pool and app client, identity pool if clients call AWS directly, AppSync API, bucket with the right IAM policies.
Export their identifiers from the stack (pool ID, client ID, API endpoint, bucket name, Region).
Pass them to Amplify.configure in the client, typically generated at build time from the stack outputs so environments never drift.
The generated, typed Amplify Data client, which depends on a Gen 2 data schema. You use plain GraphQL operations or generate types from the AppSync schema yourself.
Sandboxes and per-branch backends; your IaC pipeline owns environments.
Some convenience in authorization rules, which you now express in Cognito, IAM and AppSync resolvers directly.
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Or keep reading
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As of October 26, 2026. Provided as is, for general information, and accurate to the best of our knowledge on the date shown. Not legal, compliance, tax, financial or other professional advice. Prices, limits and vendor services change; check current vendor documentation before relying on anything here. Terms of use.