Use `Invoke` with an AWS SDK or CLI

The following code examples show how to use Invoke.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:

Learn the basics

.NET

AWS SDK for .NET

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


    /// <summary>
    /// Invoke a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to
    /// invoke.</param
    /// <param name="parameters">The parameter values that will be passed to the function.</param>
    /// <returns>A System Threading Task.</returns>
    public async Task<string> InvokeFunctionAsync(
        string functionName,
        string parameters)
    {
        var payload = parameters;
        var request = new InvokeRequest
        {
            FunctionName = functionName,
            Payload = payload,
        };

        var response = await _lambdaService.InvokeAsync(request);
        MemoryStream stream = response.Payload;
        string returnValue = System.Text.Encoding.UTF8.GetString(stream.ToArray());
        return returnValue;
    }

For API details, see Invoke in AWS SDK for .NET API Reference.

C++

SDK for C++

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::InvokeRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetLogType(logType);
        std::shared_ptr<Aws::IOStream> payload = Aws::MakeShared<Aws::StringStream>(
                "FunctionTest");
        *payload << jsonPayload.View().WriteReadable();
        request.SetBody(payload);
        request.SetContentType("application/json");
        Aws::Lambda::Model::InvokeOutcome outcome = client.Invoke(request);

        if (outcome.IsSuccess()) {
            invokeResult = std::move(outcome.GetResult());
            result = true;
            break;
        }

        else {
            std::cerr << "Error with Lambda::InvokeRequest. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            break;
        }

For API details, see Invoke in AWS SDK for C++ API Reference.

CLI

AWS CLI

Example 1: To invoke a Lambda function synchronously

The following invoke example invokes the my-function function synchronously. The cli-binary-format option is required if you're using AWS CLI version 2. For more information, see AWS CLI supported global command line options in the AWS Command Line Interface User Guide.


aws lambda invoke \
    --function-name my-function \
    --cli-binary-format raw-in-base64-out \
    --payload '{ "name": "Bob" }' \
    response.json

Output:


{
    "ExecutedVersion": "$LATEST",
    "StatusCode": 200
}

For more information, see Synchronous Invocation in the AWS Lambda Developer Guide.

Example 2: To invoke a Lambda function asynchronously

The following invoke example invokes the my-function function asynchronously. The cli-binary-format option is required if you're using AWS CLI version 2. For more information, see AWS CLI supported global command line options in the AWS Command Line Interface User Guide.


aws lambda invoke \
    --function-name my-function \
    --invocation-type Event \
    --cli-binary-format raw-in-base64-out \
    --payload '{ "name": "Bob" }' \
    response.json

Output:


{
    "StatusCode": 202
}

For more information, see Asynchronous Invocation in the AWS Lambda Developer Guide.

For API details, see Invoke in AWS CLI Command Reference.

Go

SDK for Go V2

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.



import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// Invoke invokes the Lambda function specified by functionName, passing the parameters
// as a JSON payload. When getLog is true, types.LogTypeTail is specified, which tells
// Lambda to include the last few log lines in the returned result.
func (wrapper FunctionWrapper) Invoke(ctx context.Context, functionName string, parameters any, getLog bool) *lambda.InvokeOutput {
	logType := types.LogTypeNone
	if getLog {
		logType = types.LogTypeTail
	}
	payload, err := json.Marshal(parameters)
	if err != nil {
		log.Panicf("Couldn't marshal parameters to JSON. Here's why %v\n", err)
	}
	invokeOutput, err := wrapper.LambdaClient.Invoke(ctx, &lambda.InvokeInput{
		FunctionName: aws.String(functionName),
		LogType:      logType,
		Payload:      payload,
	})
	if err != nil {
		log.Panicf("Couldn't invoke function %v. Here's why: %v\n", functionName, err)
	}
	return invokeOutput
}

For API details, see Invoke in AWS SDK for Go API Reference.

Java

SDK for Java 2.x

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


    /**
     * Invokes a specific AWS Lambda function.
     *
     * @param awsLambda    an instance of {@link LambdaClient} to interact with the AWS Lambda service
     * @param functionName the name of the AWS Lambda function to be invoked
     */
    public static void invokeFunction(LambdaClient awsLambda, String functionName) {
        InvokeResponse res;
        try {
            // Need a SdkBytes instance for the payload.
            JSONObject jsonObj = new JSONObject();
            jsonObj.put("inputValue", "2000");
            String json = jsonObj.toString();
            SdkBytes payload = SdkBytes.fromUtf8String(json);

            InvokeRequest request = InvokeRequest.builder()
                .functionName(functionName)
                .payload(payload)
                .build();

            res = awsLambda.invoke(request);
            String value = res.payload().asUtf8String();
            System.out.println(value);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

For API details, see Invoke in AWS SDK for Java 2.x API Reference.

JavaScript

SDK for JavaScript (v3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


const invoke = async (funcName, payload) => {
  const client = new LambdaClient({});
  const command = new InvokeCommand({
    FunctionName: funcName,
    Payload: JSON.stringify(payload),
    LogType: LogType.Tail,
  });

  const { Payload, LogResult } = await client.send(command);
  const result = Buffer.from(Payload).toString();
  const logs = Buffer.from(LogResult, "base64").toString();
  return { logs, result };
};

For API details, see Invoke in AWS SDK for JavaScript API Reference.

Kotlin

SDK for Kotlin

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


suspend fun invokeFunction(functionNameVal: String) {
    val json = """{"inputValue":"1000"}"""
    val byteArray = json.trimIndent().encodeToByteArray()
    val request =
        InvokeRequest {
            functionName = functionNameVal
            logType = LogType.Tail
            payload = byteArray
        }

    LambdaClient { region = "us-west-2" }.use { awsLambda ->
        val res = awsLambda.invoke(request)
        println("${res.payload?.toString(Charsets.UTF_8)}")
        println("The log result is ${res.logResult}")
    }
}

For API details, see Invoke in AWS SDK for Kotlin API reference.

PHP

SDK for PHP

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


    public function invoke($functionName, $params, $logType = 'None')
    {
        return $this->lambdaClient->invoke([
            'FunctionName' => $functionName,
            'Payload' => json_encode($params),
            'LogType' => $logType,
        ]);
    }

For API details, see Invoke in AWS SDK for PHP API Reference.

Python

SDK for Python (Boto3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def invoke_function(self, function_name, function_params, get_log=False):
        """
        Invokes a Lambda function.

        :param function_name: The name of the function to invoke.
        :param function_params: The parameters of the function as a dict. This dict
                                is serialized to JSON before it is sent to Lambda.
        :param get_log: When true, the last 4 KB of the execution log are included in
                        the response.
        :return: The response from the function invocation.
        """
        try:
            response = self.lambda_client.invoke(
                FunctionName=function_name,
                Payload=json.dumps(function_params),
                LogType="Tail" if get_log else "None",
            )
            logger.info("Invoked function %s.", function_name)
        except ClientError:
            logger.exception("Couldn't invoke function %s.", function_name)
            raise
        return response

For API details, see Invoke in AWS SDK for Python (Boto3) API Reference.

Ruby

SDK for Ruby

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Invokes a Lambda function.
  # @param function_name [String] The name of the function to invoke.
  # @param payload [nil] Payload containing runtime parameters.
  # @return [Object] The response from the function invocation.
  def invoke_function(function_name, payload = nil)
    params = { function_name: function_name }
    params[:payload] = payload unless payload.nil?
    @lambda_client.invoke(params)
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error executing #{function_name}:\n #{e.message}")
  end

For API details, see Invoke in AWS SDK for Ruby API Reference.

Rust

SDK for Rust

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


    /** Invoke the lambda function using calculator InvokeArgs. */
    pub async fn invoke(&self, args: InvokeArgs) -> Result<InvokeOutput, anyhow::Error> {
        info!(?args, "Invoking {}", self.lambda_name);
        let payload = serde_json::to_string(&args)?;
        debug!(?payload, "Sending payload");
        self.lambda_client
            .invoke()
            .function_name(self.lambda_name.clone())
            .payload(Blob::new(payload))
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

fn log_invoke_output(invoke: &InvokeOutput, message: &str) {
    if let Some(payload) = invoke.payload().cloned() {
        let payload = String::from_utf8(payload.into_inner());
        info!(?payload, message);
    } else {
        info!("Could not extract payload")
    }
    if let Some(logs) = invoke.log_result() {
        debug!(?logs, "Invoked function logs")
    } else {
        debug!("Invoked function had no logs")
    }
}

For API details, see Invoke in AWS SDK for Rust API reference.

SAP ABAP

SDK for SAP ABAP

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.


    TRY.
        DATA(lv_json) = /aws1/cl_rt_util=>string_to_xstring(
          `{`  &&
            `"action": "increment",`  &&
            `"number": 10` &&
          `}`
        ).
        oo_result =  lo_lmd->invoke(                  " oo_result is returned for testing purposes. "
                 iv_functionname = iv_function_name
                 iv_payload = lv_json
             ).
        MESSAGE 'Lambda function invoked.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvrequestcontex.
        MESSAGE 'Unable to parse request body as JSON.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidzipfileex.
        MESSAGE 'The deployment package could not be unzipped.' TYPE 'E'.
      CATCH /aws1/cx_lmdrequesttoolargeex.
        MESSAGE 'Invoke request body JSON input limit was exceeded by the request payload.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
      CATCH /aws1/cx_lmdunsuppedmediatyp00.
        MESSAGE 'Invoke request body does not have JSON as its content type.' TYPE 'E'.
    ENDTRY.

For API details, see Invoke in AWS SDK for SAP ABAP API reference.

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Use Invoke with an AWS SDK or CLI

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Use `Invoke` with an AWS SDK or CLI