Invokes a Lambda function. For an example, see Create the Lambda Function and Test It Manually.
Specify just a function name to invoke the latest version of the function. To invoke a published version, use the Qualifier parameter to specify a version or alias.
If you use the RequestResponse (synchronous) invocation option, the function will be invoked only once. If you use the Event (asynchronous) invocation option, the function will be invoked at least once in response to an event and the function must be idempotent to handle this.
For functions with a long timeout, your client may be disconnected during synchronous invocation while it waits for a response. Configure your HTTP client, SDK, firewall, proxy, or operating system to allow for long connections with timeout or keep-alive settings.
This operation requires permission for the lambda:InvokeFunction action.
The TooManyRequestsException noted below will return the following: ConcurrentInvocationLimitExceeded will be returned if you have no functions with reserved concurrency and have exceeded your account concurrent limit or if a function without reserved concurrency exceeds the account's unreserved concurrency limit. ReservedFunctionConcurrentInvocationLimitExceeded will be returned when a function with reserved concurrency exceeds its configured concurrency limit.
POST /2015-03-31/functions/FunctionName/invocations?Qualifier=Qualifier HTTP/1.1
X-Amz-Invocation-Type: InvocationType
X-Amz-Log-Type: LogType
X-Amz-Client-Context: ClientContext
Payload
The request requires the following URI parameters.
** ClientContext **
Using the ClientContext you can pass client-specific information to the Lambda function you are invoking. You can then process the client information in your Lambda function as you choose through the context variable. For an example of a ClientContext JSON, see PutEvents in the Amazon Mobile Analytics API Reference and User Guide.
The ClientContext JSON must be base64-encoded and has a maximum size of 3583 bytes.
ClientContext information is returned only if you use the synchronous (RequestResponse) invocation type.
** FunctionName ** The name of the lambda function.
Name formats
- Function name -
MyFunction. - Function ARN -
arn:aws:lambda:us-west-2:123456789012:function:MyFunction. - Partial ARN -
123456789012:function:MyFunction. The length constraint applies only to the full ARN. If you specify only the function name, it is limited to 64 characters in length.
Length Constraints: Minimum length of 1. Maximum length of 170.
Pattern:(arn:(aws[a-zA-Z-]*)?:lambda:)?([a-z]{2}(-gov)?-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_\.]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?
** InvocationType ** Choose from the following options.
RequestResponse(default) - Invoke the function synchronously. Keep the connection open until the function returns a response or times out.Event- Invoke the function asynchronously. Send events that fail multiple times to the function's dead-letter queue (if configured).DryRun- Validate parameter values and verify that the user or role has permission to invoke the function. Valid Values:Event | RequestResponse | DryRun
** LogType **
You can set this optional parameter to Tail in the request only if you specify the InvocationType parameter with value RequestResponse. In this case, AWS Lambda returns the base64-encoded last 4 KB of log data produced by your Lambda function in the x-amz-log-result header.
Valid Values: None | Tail
** Qualifier **
Specify a version or alias to invoke a published version of the function.
Length Constraints: Minimum length of 1. Maximum length of 128.
Pattern: (|[a-zA-Z0-9$_-]+)
The request accepts the following binary data.
** Payload ** JSON that you want to provide to your Lambda function as input.
HTTP/1.1 StatusCode
X-Amz-Function-Error: FunctionError
X-Amz-Log-Result: LogResult
X-Amz-Executed-Version: ExecutedVersion
Payload
If the action is successful, the service sends back the following HTTP response.
** StatusCode **
The HTTP status code will be in the 200 range for successful request. For the RequestResponse invocation type this status code will be 200. For the Event invocation type this status code will be 202. For the DryRun invocation type the status code will be 204.
The response returns the following HTTP headers.
** ExecutedVersion **
The function version that has been executed. This value is returned only if the invocation type is RequestResponse. For more information, see Traffic Shifting Using Aliases.
Length Constraints: Minimum length of 1. Maximum length of 1024.
Pattern: (\$LATEST|[0-9]+)
** FunctionError **
Indicates whether an error occurred while executing the Lambda function. If an error occurred this field will have one of two values; Handled or Unhandled. Handled errors are errors that are reported by the function while the Unhandled errors are those detected and reported by AWS Lambda. Unhandled errors include out of memory errors and function timeouts. For information about how to report an Handled error, see Programming Model.
** LogResult **
It is the base64-encoded logs for the Lambda function invocation. This is present only if the invocation type is RequestResponse and the logs were requested.
The response returns the following as the HTTP body.
** Payload **
It is the JSON representation of the object returned by the Lambda function. This is present only if the invocation type is RequestResponse.
In the event of a function error this field contains a message describing the error. For the Handled errors the Lambda function will report this message. For Unhandled errors AWS Lambda reports the message.
EC2AccessDeniedException
Need additional permissions to configure VPC settings.
HTTP Status Code: 502
EC2ThrottledException
AWS Lambda was throttled by Amazon EC2 during Lambda function initialization using the execution role provided for the Lambda function.
HTTP Status Code: 502
EC2UnexpectedException
AWS Lambda received an unexpected EC2 client exception while setting up for the Lambda function.
HTTP Status Code: 502
ENILimitReachedException
AWS Lambda was not able to create an Elastic Network Interface (ENI) in the VPC, specified as part of Lambda function configuration, because the limit for network interfaces has been reached.
HTTP Status Code: 502
InvalidParameterValueException
One of the parameters in the request is invalid. For example, if you provided an IAM role for AWS Lambda to assume in the CreateFunction or the UpdateFunctionConfiguration API, that AWS Lambda is unable to assume you will get this exception.
HTTP Status Code: 400
InvalidRequestContentException
The request body could not be parsed as JSON.
HTTP Status Code: 400
InvalidRuntimeException
The runtime or runtime version specified is not supported.
HTTP Status Code: 502
InvalidSecurityGroupIDException
The Security Group ID provided in the Lambda function VPC configuration is invalid.
HTTP Status Code: 502
InvalidSubnetIDException
The Subnet ID provided in the Lambda function VPC configuration is invalid.
HTTP Status Code: 502
InvalidZipFileException
AWS Lambda could not unzip the deployment package.
HTTP Status Code: 502
KMSAccessDeniedException
Lambda was unable to decrypt the environment variables because KMS access was denied. Check the Lambda function's KMS permissions.
HTTP Status Code: 502
KMSDisabledException
Lambda was unable to decrypt the environment variables because the KMS key used is disabled. Check the Lambda function's KMS key settings.
HTTP Status Code: 502
KMSInvalidStateException
Lambda was unable to decrypt the environment variables because the KMS key used is in an invalid state for Decrypt. Check the function's KMS key settings.
HTTP Status Code: 502
KMSNotFoundException
Lambda was unable to decrypt the environment variables because the KMS key was not found. Check the function's KMS key settings.
HTTP Status Code: 502
RequestTooLargeException
The request payload exceeded the Invoke request body JSON input limit. For more information, see Limits.
HTTP Status Code: 413
ResourceNotFoundException
The resource (for example, a Lambda function or access policy statement) specified in the request does not exist.
HTTP Status Code: 404
ServiceException
The AWS Lambda service encountered an internal error.
HTTP Status Code: 500
SubnetIPAddressLimitReachedException
AWS Lambda was not able to set up VPC access for the Lambda function because one or more configured subnets has no available IP addresses.
HTTP Status Code: 502
TooManyRequestsException
Request throughput limit exceeded
HTTP Status Code: 429
UnsupportedMediaTypeException
The content type of the Invoke request body is not JSON.
HTTP Status Code: 415
For more information about using this API in one of the language-specific AWS SDKs, see the following: