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The Function component lets you add serverless functions to your app. It uses AWS Lambda.

​
Constructor

sst.config.ts
new sst.aws.Function("MyFunction", {
  handler: "src/lambda.handler"
});

​
Parameters

​
handler

​
handler
string
required
Path to the handler for the function.
  • For Node.js: {path}/{file}.{method} format
  • For Python: {path}/{file}.{method} format
  • For Go: {path} to the Go module
  • For Rust: {path} to the Rust crate
{
  handler: "packages/functions/src/main.handler"
}

​
runtime

​
runtime
string
default:"nodejs24.x"
The language runtime for the function.
{
  runtime: "nodejs24.x"
}
Supported values: "nodejs18.x", "nodejs20.x", "nodejs22.x", "nodejs24.x", "go", "rust", "provided.al2", "provided.al2023", "python3.9", "python3.10", "python3.11", "python3.12", "python3.13"

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timeout

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timeout
duration
default:"20 seconds"
The maximum amount of time the function can run. Between 1 second and 900 seconds (15 minutes).
{
  timeout: "900 seconds"
}
If a function is connected to API Gateway, it will time out after 30 seconds regardless of this setting.

​
memory

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memory
string
default:"1024 MB"
The amount of memory allocated for the function. Between 128 MB and 10240 MB in 1 MB increments.
{
  memory: "2048 MB"
}
While less memory is cheaper, larger functions can process faster and might be more cost effective.
​
link
array
Link resources to your function. This will:
  1. Grant permissions to access the resources
  2. Allow you to access them in your function using the SDK
{
  link: [bucket, stripeKey]
}

​
environment

​
environment
Record<string, string>
Key-value pairs of Lambda environment variables.
{
  environment: {
    DEBUG: "true"
  }
}
The total size of environment variables cannot exceed 4 KB.

​
permissions

​
permissions
array
Permissions to access other resources. These are added to the function’s IAM role.
{
  permissions: [
    {
      actions: ["s3:GetObject", "s3:PutObject"],
      resources: ["arn:aws:s3:::my-bucket/*"]
    }
  ]
}
If you link the function to a resource, the permissions to access it are automatically added.

​
url

​
url
boolean | object
default:"false"
Enable Lambda function URLs.
{
  url: true
}
Configure the authorization and CORS settings:
{
  url: {
    authorization: "iam",
    cors: {
      allowOrigins: ["https://example.com"]
    }
  }
}

​
vpc

​
vpc
Vpc | object
Connect the function to private subnets in a VPC.
{
  vpc: myVpc
}
Where myVpc is:
const myVpc = new sst.aws.Vpc("MyVpc");

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Properties

​
name

​
arn

​
url

​
nodes

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SDK

When you link a Function to another resource, you can access it in your function code using the SDK.
src/lambda.ts
import { Resource } from "sst";

console.log(Resource.MyFunction.name);

​
Examples

​
Set additional config

sst.config.ts
new sst.aws.Function("MyFunction", {
  handler: "src/lambda.handler",
  timeout: "3 minutes",
  memory: "2048 MB"
});
Link resources to the function:
sst.config.ts
const bucket = new sst.aws.Bucket("MyBucket");

new sst.aws.Function("MyFunction", {
  handler: "src/lambda.handler",
  link: [bucket]
});
Access linked resources in your function:
src/lambda.ts
import { Resource } from "sst";

console.log(Resource.MyBucket.name);

​
Enable function URLs

sst.config.ts
new sst.aws.Function("MyFunction", {
  handler: "src/lambda.handler",
  url: true
});

​
Customize bundling

sst.config.ts
new sst.aws.Function("MyFunction", {
  handler: "src/lambda.handler",
  nodejs: {
    install: ["pg"]
  }
});

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