Lambda / Client / add_permission



Grants an Amazon Web Service, Amazon Web Services account, or Amazon Web Services organization 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. Note: Lambda does not support adding policies to version $LATEST.

To grant permission to another account, specify the account ID as the Principal. To grant permission to an organization defined in Organizations, specify the organization ID as the PrincipalOrgID. For Amazon Web Services, the principal is a domain-style identifier that the service defines, such as or For Amazon Web 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 operation adds a statement to a resource-based permissions policy for the function. For more information about function policies, see Using resource-based policies for Lambda.

See also: AWS API Documentation

Request Syntax

response = client.add_permission(
  • FunctionName (string) –


    The name or ARN of the Lambda function, version, or alias.

    Name formats

    • Function namemy-function (name-only), my-function:v1 (with alias).

    • Function ARNarn:aws:lambda:us-west-2:123456789012:function:my-function.

    • Partial ARN123456789012: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.

  • StatementId (string) –


    A statement identifier that differentiates the statement from others in the same policy.

  • Action (string) –


    The action that the principal can use on the function. For example, lambda:InvokeFunction or lambda:GetFunction.

  • Principal (string) –


    The Amazon Web Service or Amazon Web Services account that invokes the function. If you specify a service, use SourceArn or SourceAccount to limit who can invoke the function through that service.

  • SourceArn (string) –

    For Amazon Web Services, the ARN of the Amazon Web Services resource that invokes the function. For example, an Amazon S3 bucket or Amazon SNS topic.

    Note that Lambda configures the comparison using the StringLike operator.

  • SourceAccount (string) – For Amazon Web Service, the ID of the Amazon Web Services account that owns the resource. Use this together with SourceArn to ensure that the specified account owns the resource. It is possible for an Amazon S3 bucket to be deleted by its owner and recreated by another account.

  • EventSourceToken (string) – For Alexa Smart Home functions, a token that the invoker must supply.

  • Qualifier (string) – Specify a version or alias to add permissions to a published version of the function.

  • RevisionId (string) – Update the policy only 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.

  • PrincipalOrgID (string) – The identifier for your organization in Organizations. Use this to grant permissions to all the Amazon Web Services accounts under this organization.

  • FunctionUrlAuthType (string) – The type of authentication that your function URL uses. Set to AWS_IAM if you want to restrict access to authenticated users only. Set to NONE if you want to bypass IAM authentication to create a public endpoint. For more information, see Security and auth model for Lambda function URLs.

Return type:



Response Syntax

    'Statement': 'string'

Response Structure

  • (dict) –

    • Statement (string) –

      The permission statement that’s added to the function policy.


  • Lambda.Client.exceptions.ServiceException

  • Lambda.Client.exceptions.ResourceNotFoundException

  • Lambda.Client.exceptions.ResourceConflictException

  • Lambda.Client.exceptions.InvalidParameterValueException

  • Lambda.Client.exceptions.PolicyLengthExceededException

  • Lambda.Client.exceptions.TooManyRequestsException

  • Lambda.Client.exceptions.PreconditionFailedException


The following example adds permission for Amazon S3 to invoke a Lambda function named my-function for notifications from a bucket named my-bucket-1xpuxmplzrlbh in account 123456789012.

response = client.add_permission(


Expected Output:

    'Statement': '{"Sid":"s3","Effect":"Allow","Principal":{"Service":""},"Action":"lambda:InvokeFunction","Resource":"arn:aws:lambda:us-east-2:123456789012:function:my-function","Condition":{"StringEquals":{"AWS:SourceAccount":"123456789012"},"ArnLike":{"AWS:SourceArn":"arn:aws:s3:::my-bucket-1xpuxmplzrlbh"}}}',
    'ResponseMetadata': {
        '...': '...',

The following example adds permission for account 223456789012 invoke a Lambda function named my-function.

response = client.add_permission(


Expected Output:

    'Statement': '{"Sid":"xaccount","Effect":"Allow","Principal":{"AWS":"arn:aws:iam::223456789012:root"},"Action":"lambda:InvokeFunction","Resource":"arn:aws:lambda:us-east-2:123456789012:function:my-function"}',
    'ResponseMetadata': {
        '...': '...',