AWS Lambda connector

Invoke an AWS Lambda function from your BPMN process and use its response in later steps.

About this connector

The AWS Lambda connector is an outbound connector that connects your BPMN service with the AWS Lambda service. Use it to run serverless code, such as a calculation or a call into another AWS service, as part of a process, and to pass JSON data to the function and receive its result.

The connector supports synchronous invocation only. It waits for the function to finish and returns its response. Asynchronous (event-driven) invocation isn't available.

Prerequisites

To use the AWS Lambda connector, you need the following:

Prerequisite	Description
AWS Lambda function	A deployed function you want to invoke.
AWS IAM user and permissions	An IAM access key and secret key pair with permission to run the function. Not required if you use the default credentials chain (hybrid/Self-Managed only) or a saved AWS credential.

note

Use secrets to avoid exposing your AWS IAM credentials as plain text. Refer to managing secrets to learn more.

Use this connector

New to using an outbound connector? Learn how to add and use this type of connector, apply element templates, use connector secrets, handle results and errors, and more.

Use an outbound connector

Configuration

Authentication

Select an authentication method for the connector. Learn more about the available options in AWS authentication types.

Property	Type	Required	Description	Example
AWS credential	Configuration	No	Select a saved AWS credential, which can include a default region. When you select a credential, the Authentication, Access key, and Secret key fields are hidden. Learn more about credentials.
Authentication	Dropdown	Yes	The AWS authentication strategy: Credentials, or Default Credentials Chain (Hybrid/Self-Managed only). Shown when no AWS credential is selected.	Credentials
Access key	String	Yes	IAM access key of a user with the necessary permissions for this connector. Shown when Authentication is Credentials and no AWS credential is selected.	{{secrets.MY_AWS_ACCESS_KEY}}
Secret key	String	Yes	IAM secret key of a user with the necessary permissions for this connector. Shown when Authentication is Credentials and no AWS credential is selected.	{{secrets.MY_AWS_SECRET_KEY}}

Region

Property	Type	Required	Description	Example
Region	String	Yes	The AWS region where your function is hosted. Refer to Regions and Zones to learn more. When you select an AWS credential, this field is optional: it overrides the credential's default region, and is required if the credential has no default region.	us-east-1

AWS authentication types

You can authenticate the connector with AWS in the following ways:

• Credentials: Use this option if your AWS account administrator provided a pair of access and secret keys. It applies to SaaS and Self-Managed.
• Default Credentials Chain (Hybrid/Self-Managed only): Use this option if your system relies on an implicit authentication mechanism, such as role-based authentication, credentials supplied through environment variables, or files on the target host. It applies only to Self-Managed or hybrid distributions, and uses the Default Credential Provider Chain to resolve credentials.
• AWS credential: Select a saved credential instead of entering authentication details on the task.

Operations

Invoke function

Invoke an AWS Lambda function synchronously and return its response.

Input parameters

Property	Type	Required	Description	Example
Operation type	Dropdown	Yes	The invocation type. Invoke function (sync) is the only option.	Invoke function (sync)
Function name	String	Yes	The name, ARN, or alias of your function.	my-function
Payload	Text	Yes	The JSON input passed to your Lambda function when it is invoked. Use a FEEL expression to build it from process variables.	= { "orderId": orderId }

Output

The connector returns an object with the following fields:

Field	Description
statusCode	The HTTP status code returned by the AWS Lambda Invoke API. It shows whether AWS Lambda accepted and handled the invocation request, not whether the function itself succeeded.
executedVersion	The version of the Lambda function that ran.
payload	The response returned by the Lambda function, or an error object. If your function returns its own statusCode, that value describes the function result and is separate from the top-level statusCode.

For example, for a function that returns an order status:

{
  "statusCode": 200,
  "executedVersion": "$LATEST",
  "payload": {
    "orderId": "1001",
    "status": "shipped"
  }
}

To read a statusCode that your function returns, use response.payload.statusCode rather than response.statusCode.

To map the response into process variables, use Result variable to store the whole response, or Result expression to map individual fields:

= {
  "myNewReportStatusCode": response.statusCode,
  "myNewReportExecutedVersion": response.executedVersion,
  "myNewReportPayload": response.payload
}

Troubleshooting

To learn about general error handling in Camunda, see BPMN errors and failing jobs.

Further resources

• AWS Lambda developer guide