Configure Functions

defineFunction comes out-of-the-box with sensible but minimal defaults. The following options are provided to tweak the function configuration.

name

By default, functions are named based on the directory the defineFunction call is placed in. In the above example, defining the function in amplify/functions/my-demo-function/resource.ts will cause the function to be named my-demo-function by default.

If an entry is specified, then the name defaults to the basename of the entry path. For example, an entry of ./signup-trigger-handler.ts would cause the function name to default to signup-trigger-handler.

This optional property can be used to explicitly set the name of the function.

export const myDemoFunction = defineFunction({
  entry: './demo-function-handler.ts',
  name: 'overrideName' // explicitly set the name to override the default naming behavior
});

timeoutSeconds

By default, functions will time out after 3 seconds. This can be configured to any whole number of seconds up to 15 minutes.

export const myDemoFunction = defineFunction({
Copy highlighted code example
  timeoutSeconds: 60 // 1 minute timeout
});

memoryMB

By default, functions have 512 MB of memory allocated to them. This can be configured from 128 MB up to 10240 MB. Note that this can increase the cost of function invocation. For more pricing information see here.

export const myDemoFunction = defineFunction({
Copy highlighted code example
  memoryMB: 256 // allocate 256 MB of memory to the function.
});

runtime

Currently, only Node runtimes are supported by defineFunction. However, you can change the Node version that is used by the function. The default is the oldest Node LTS version that is supported by AWS Lambda (currently Node 18).

If you wish to use an older version of Node, keep an eye on the Lambda Node version deprecation schedule. As Lambda removes support for old Node versions, you will have to update to newer supported versions.

export const myDemoFunction = defineFunction({
  runtime: 20 // use Node 20
});

entry

By default, Amplify will look for your function handler in a file called handler.ts in the same directory as the file where defineFunction is called. To point to a different handler location, specify an entry value.

export const myDemoFunction = defineFunction({
  entry: './path/to/handler.ts' // this path should either be absolute or relative to the current file
});

resourceGroupName

By default, functions are grouped together in a resource group named function. You can override this to group related function with other Amplify resources like auth, data, storage, or separate them into your own custom group. This is typically useful when you have resources that depend on each other and you want to group them together.

export const myDemoFunction = defineFunction({
  resourceGroupName: 'data'
});