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Deploying to AWS

The Serverless Framework was designed to provision your AWS Lambda Functions, Events and infrastructure Resources safely and quickly. It does this via a couple of methods designed for different types of deployments.

Deploy All

This is the main method for doing deployments with the Serverless Framework:

bash

serverless deploy

Use this method when you have updated your Function, Event or Resource configuration in serverless.yml and you want to deploy that change (or multiple changes at the same time) to Amazon Web Services.

Note: You can always enforce a deployment using the --force option, or specify a different configuration file name with the the --config option.

How It Works

The Serverless Framework translates all syntax in serverless.yml to a single AWS CloudFormation template. By depending on CloudFormation for deployments, users of the Serverless Framework get the safety and reliability of CloudFormation.

An AWS CloudFormation template is created from your serverless.yml.
If a Stack has not yet been created, then it is created with no resources except for an S3 Bucket, which will store zip files of your Function code.
If you're using locally build ECR images, dedicated ECR repository is created for your service. You also will be logged to that repository via docker login if needed.
The code of your Functions is then packaged into zip files.
If you're using locally build ECR images, they are built and uploaded to ECR.
Serverless fetches the hashes for all files of the previous deployment (if any) and compares them against the hashes of the local files.
Serverless terminates the deployment process if all file hashes are the same.
Zip files of your Functions' code are uploaded to your Code S3 Bucket.
Any IAM Roles, Functions, Events and Resources are added to the AWS CloudFormation template.
The CloudFormation Stack is updated with the new CloudFormation template.
Each deployment publishes a new version for each function in your service.

Note: AWS SSM and S3 permissions are required for deployments to manage state and upload deployment packages. For more details, see AWS Credentials Requirement for Packaging.

Deployment method

Since Serverless Framework v4, deployments are by default done using CloudFormation direct deployments. This is the recommended approach for most users.

If you want to instead use CloudFormation change sets, you can enable it via the deploymentMethod option:

yml

provider:
  name: aws
  deploymentMethod: changesets

AWS SDK for JavaScript v3

Serverless Framework’s internal AWS request layer supports the AWS SDK for JavaScript v3. By default, the Framework continues to use the v2 path for maximum compatibility, but you can opt in to v3 without changing your deployment commands or configuration. To enable v3 for deployments, set an environment variable when running the CLI:

bash

SLS_AWS_SDK=3 serverless deploy

This toggle only affects the Framework’s own calls to AWS during packaging and deployment (e.g., S3 uploads, CloudFormation updates). Your Lambda function code is independent—use @aws-sdk/* (v3) or aws-sdk (v2) in handlers as you prefer. Credentials behavior is unchanged: both paths use the standard AWS credentials provider chain (profiles, SSO, environment variables). In CI/CD, set SLS_AWS_SDK=3 in your pipeline environment before invoking the Serverless CLI.

Note: AWS announced end-of-support for the AWS SDK for JavaScript v2. See the official notice: Announcing end-of-support for AWS SDK for JavaScript v2. We recommend adopting v3 in new projects and planning migrations where feasible.

Tips

Use this in your CI/CD systems, as it is the safest method of deployment.
You can print the progress during the deployment if you use verbose mode, like this:
bash
```
serverless deploy --verbose
```
This method uses the AWS CloudFormation Stack Update method. CloudFormation is slow, so this method is slower. If you want to develop more quickly, use the serverless deploy function command (described below)
This method defaults to dev stage and us-east-1 region. You can change the default stage and region in your serverless.yml file by setting the stage and region properties inside a provider object as the following example shows:
yml
```
# serverless.yml

service: service-name
provider:
  name: aws
  stage: beta
  region: us-west-2
```
You can also deploy to different stages and regions by passing in flags to the command:
bash
```
serverless deploy --stage production --region eu-central-1
```
You can specify your own S3 bucket which should be used to store all the deployment artifacts. The deploymentBucket config which is nested under provider lets you e.g. set the name or the serverSideEncryption method for this bucket. If you don't provide your own bucket, Serverless will create a bucket which uses default AES256 encryption.
You can specify your own S3 prefix which should be used to store all the deployment artifacts. The deploymentPrefix config which is nested under provider lets you set the prefix under which the deployment artifacts will be stored. If not specified, defaults to serverless.
You can make uploading to S3 faster by adding --aws-s3-accelerate
You can disable creation of default S3 bucket policy by setting skipPolicySetup under deploymentBucket config. It only applies to deployment bucket that is automatically created by the Serverless Framework.
You can enable versioning for the deployment bucket by setting versioning under deploymentBucket config to true.

Check out the deploy command docs for all details and options.

For information on multi-region deployments, checkout this article.

Deploy Function

This deployment method does not touch your AWS CloudFormation Stack. Instead, it simply overwrites the zip file of the current function on AWS. This method is much faster, since it does not rely on CloudFormation.

bash

serverless deploy function --function myFunction

-Note: You can always enforce a deployment using the --force option. -Note: You can use --update-config to change only Lambda configuration without deploying code.

How It Works

The Framework packages up the targeted AWS Lambda Function into a zip file.
The Framework fetches the hash of the already uploaded function .zip file and compares it to the local .zip file hash.
The Framework terminates if both hashes are the same.
That zip file is uploaded to your S3 bucket using the same name as the previous function, which the CloudFormation stack is pointing to.

Tips

Use this when you are developing and want to test on AWS because it's much faster.
During development, people will often run this command several times, as opposed to serverless deploy which is only run when larger infrastructure provisioning is required.

Check out the deploy command docs for all details and options.

Deploying a package

This deployment option takes a deployment directory that has already been created with serverless package and deploys it to the cloud provider. This allows you to easily integrate CI / CD workflows with the Serverless Framework.

bash

serverless deploy --package path-to-package

How It Works

The argument to the --package flag is a directory that has been previously packaged by Serverless (with serverless package).
The deploy process bypasses the package step and uses the existing package to deploy and update CloudFormation stacks.