Grants an AWS service or another account permission to use a function. You can apply the policy at the function level, or specify a qualifier to restrict access to a single version or alias. If you use a qualifier, the invoker must use the full Amazon Resource Name (ARN) of that version or alias to invoke the function.
To grant permission to another account, specify the account ID as the Principal
. For AWS services, the principal is a domain-style identifier defined by the service, like s3.amazonaws.com
or sns.amazonaws.com
. For AWS services, you can also specify the ARN of the associated resource as the SourceArn
. If you grant permission to a service principal without specifying the source, other accounts could potentially configure resources in their account to invoke your Lambda function.
This action adds a statement to a resource-based permissions policy for the function. For more information about function policies, see Lambda Function Policies.
POST /2015-03-31/functions/FunctionName/policy?Qualifier=Qualifier HTTP/1.1
Content-type: application/json
{
"Action": "string",
"EventSourceToken": "string",
"Principal": "string",
"RevisionId": "string",
"SourceAccount": "string",
"SourceArn": "string",
"StatementId": "string"
}
The request uses the following URI parameters.
** FunctionName ** The name of the Lambda function, version, or alias.
Name formats
- Function name -
my-function
(name-only),my-function:v1
(with alias). - Function ARN -
arn:aws:lambda:us-west-2:123456789012:function:my-function
. - Partial ARN -
123456789012:function:my-function
. You can append a version number or alias to any of the formats. 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 140.
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-_]+))?
Required: Yes
** Qualifier **
Specify a version or alias to add permissions to 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 data in JSON format.
** Action **
The action that the principal can use on the function. For example, lambda:InvokeFunction
or lambda:GetFunction
.
Type: String
Pattern: (lambda:[*]|lambda:[a-zA-Z]+|[*])
Required: Yes
** EventSourceToken **
For Alexa Smart Home functions, a token that must be supplied by the invoker.
Type: String
Length Constraints: Minimum length of 0. Maximum length of 256.
Pattern: [a-zA-Z0-9._\-]+
Required: No
** Principal **
The AWS service or account that invokes the function. If you specify a service, use SourceArn
or SourceAccount
to limit who can invoke the function through that service.
Type: String
Pattern: .*
Required: Yes
** RevisionId **
Only update the policy if the revision ID matches the ID that's specified. Use this option to avoid modifying a policy that has changed since you last read it.
Type: String
Required: No
** SourceAccount **
For Amazon S3, the ID of the account that owns the resource. Use this together with SourceArn
to ensure that the resource is owned by the specified account. It is possible for an Amazon S3 bucket to be deleted by its owner and recreated by another account.
Type: String
Pattern: \d{12}
Required: No
** SourceArn **
For AWS services, the ARN of the AWS resource that invokes the function. For example, an Amazon S3 bucket or Amazon SNS topic.
Type: String
Pattern: arn:(aws[a-zA-Z0-9-]*):([a-zA-Z0-9\-])+:([a-z]{2}(-gov)?-[a-z]+-\d{1})?:(\d{12})?:(.*)
Required: No
** StatementId **
A statement identifier that differentiates the statement from others in the same policy.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 100.
Pattern: ([a-zA-Z0-9-_]+)
Required: Yes
HTTP/1.1 201
Content-type: application/json
{
"Statement": "string"
}
If the action is successful, the service sends back an HTTP 201 response.
The following data is returned in JSON format by the service.
** Statement **
The permission statement that's added to the function policy.
Type: String
InvalidParameterValueException
One of the parameters in the request is invalid.
HTTP Status Code: 400
PolicyLengthExceededException
The permissions policy for the resource is too large. Learn more
HTTP Status Code: 400
PreconditionFailedException
The RevisionId provided does not match the latest RevisionId for the Lambda function or alias. Call the GetFunction
or the GetAlias
API to retrieve the latest RevisionId for your resource.
HTTP Status Code: 412
ResourceConflictException
The resource already exists, or another operation is in progress.
HTTP Status Code: 409
ResourceNotFoundException
The resource specified in the request does not exist.
HTTP Status Code: 404
ServiceException
The AWS Lambda service encountered an internal error.
HTTP Status Code: 500
TooManyRequestsException
The request throughput limit was exceeded.
HTTP Status Code: 429
For more information about using this API in one of the language-specific AWS SDKs, see the following: