Amplify has re-imagined the way frontend developers build fullstack applications. Develop and deploy without the hassle.

Page updated May 17, 2024

Use Amplify Storage with any S3 bucket

With Amplify Storage APIs, you can use your own S3 buckets instead of the Amplify-created ones.

Important: To utilize the storage APIs with an S3 bucket outside of Amplify, you must have Amplify Auth configured in your project.

Step 1 - Add necessary permissions to the S3 bucket

For the specific Amazon S3 bucket that you want to use with these APIs, you need to make sure that the associated IAM role has the necessary permissions to read and write data to that bucket.

To do this, go to Amazon S3 console > Select the S3 bucket > Permissions > Edit Bucket Policy.

Showing Amplify console showing Storage tab selected

The policy will look something like this

{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Statement1",
"Principal": { "AWS": "arn:aws:iam::<AWS-account-ID>:role/<role-name>" },
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:DeleteObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::<bucket-name>/*"
]
}
]
}

Replace <AWS-account-ID> with your AWS account ID and <role-name> with the IAM role associated with your Amplify Auth setup. Replace <bucket-name> with the S3 bucket name.

You can refer to Amazon S3's Policies and Permissions documentation for more ways to customize access to the bucket.

Step 2 - Specify S3 bucket in Amplify's backend config

Next, use the addOutput method from the backend definition object to define a custom s3 bucket by specifying the name and region of the bucket in your amplify/backend.ts file.

Important

You cannot use both a storage backend configured through Amplify and a custom S3 bucket at the same time.

If you specify a custom S3 bucket, no sandbox storage resource will be created. The provided custom S3 bucket will be used, even in the sandbox environment.

import { defineBackend } from '@aws-amplify/backend';
import { auth } from './auth/resource';
import { data } from './data/resource';
const backend = defineBackend({
auth,
data,
});
backend.addOutput({
storage: {
aws_region: "<region>",
bucket_name: "<bucket-name>"
},
});

Step 3 - Import latest amplify_outputs.json file

To ensure the local amplify_outputs.json file is up-to-date, you can run the npx ampx generate outputs command or download the latest amplify_outputs.json from the Amplify console as shown below.

outputs

Now that you've configured the necessary permissions, you can start using the storage APIs with your chosen S3 bucket.