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Amazon Lex
Developer Guide

Overview of Managing Access Permissions to Your Amazon Lex Resources

Every AWS resource is owned by an AWS account, and permissions to create or access a resource are governed by permissions policies. An account administrator can attach permissions policies to IAM identities (that is, users, groups, and roles), and some services (such as AWS Lambda) also support attaching permissions policies to resources.

Note

An account administrator (or administrator user) is a user with administrator privileges. For more information, see IAM Best Practices in the IAM User Guide.

When granting permissions, you decide who is getting the permissions, the resources they get permissions for, and the specific actions that you want to allow on those resources.

Amazon Lex Resources and Operations

In Amazon Lex, the primary resource is a bot. Amazon Lex also supports additional resource types, the intent, the slot type, the alias, and the bot channel association. Aliases and bot channel associations are referred to as subresources. For Amazon Lex, you can create subresources only in the context of an existing bot.

These resources and subresources have unique Amazon Resource Names (ARNs) associated with them as shown in the following table.

Resource Type ARN Format
Bot version arn:aws:lex:region:account-id:bot:bot-name:version
Intent arn:aws:lex:region:account-id:intent:intent-name:version
Slot type arn:aws:lex:region:account-id:slottype:slottype-name:version
Bot alias arn:aws:lex:region:account-id:bot:bot-name:alias-name
Bot channel arn:aws:lex:region:account-id:bot-channel:bot-name:alias-name:channel-name

Amazon Lex provides a set of operations to work with Amazon Lex resources. For a list of available operations, see Amazon Lex Actions.

Understanding Resource Ownership

The AWS account owns the resources that are created in the account, regardless of who created the resources. Specifically, the resource owner is the AWS account of the principal entity (that is, the root account, an IAM user, or an IAM role) that authenticates the resource creation request. The following examples illustrate how this works:

  • If you use the root account credentials of your AWS account to create a bot, your AWS account is the owner of the resource (in Amazon Lex, the resource is the bot).

  • If you create an IAM user in your AWS account and grant permissions to create a bot to that user, the user can create a bot. However, your AWS account, to which the user belongs, owns the bot resource.

  • If you create an IAM role in your AWS account with permissions to create a bot, anyone who can assume the role can create a bot. Your AWS account, to which the role belongs, owns the bot resource.

Managing Access to Resources

A permissions policy describes who has access to what. The following section explains the available options for creating permissions policies.

Note

This section discusses using IAM in the context of Amazon Lex. It doesn't provide detailed information about the IAM service. For complete IAM documentation, see What Is IAM? in the IAM User Guide. For information about IAM policy syntax and descriptions, see AWS IAM Policy Reference in the IAM User Guide.

Policies attached to an IAM identity are referred to as identity-based policies (IAM polices) and policies attached to a resource are referred to as resource-based policies. Amazon Lex supports only identity-based policies (IAM policies).

Identity-Based Policies (IAM Policies)

You can attach policies to IAM identities. For example, you can do the following:

  • Attach a permissions policy to a user or a group in your account – To grant a user or a group of users permissions to create a Amazon Lex resource, such as a bot, you can attach a permissions policy to a user or group that the user belongs to.

  • Attach a permissions policy to a role (grant cross-account permissions) – To grant cross-account permissions, you can attach an identity-based permissions policy to an IAM role. For example, the administrator in Account A can create a role to grant cross-account permissions to another AWS account (for example, Account B) or an AWS service as follows:

    1. Account A administrator creates an IAM role and attaches a permissions policy to the role that grants permissions on resources in Account A.

    2. Account A administrator attaches a trust policy to the role identifying Account B as the principal who can assume the role.

    3. Account B administrator can then delegate permissions to assume the role to any users in Account B. Doing this allows users in Account B to create or access resources in Account A. If you want to grant an AWS service permissions to assume the role, the principal in the trust policy can also be an AWS service principal.

    For more information about using IAM to delegate permissions, see Access Management in the IAM User Guide.

The following is an example policy that allows the user to perform the PutBot action for your AWS account.

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{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "lex:PutBot" "Resource": [ "*" ] } ] }

For more information about using identity-based policies with Amazon Lex, see Using Identity-Based Polices (IAM Policies) for Amazon Lex. For more information about users, groups, roles, and permissions, see Identities (Users, Groups, and Roles) in the IAM User Guide.

Resource-Based Policies

Other services, such as Lambda, support resource-based permissions policies. For example, you can attach a policy to an S3 bucket to manage access permissions to that bucket. Amazon Lex doesn't support resource-based policies. However, it does use resource-based policies to access Lambda and Amazon Polly services. 

Specifying Policy Elements: Actions, Effects, and Principals

For each Amazon Lex resource (see Amazon Lex Resources and Operations), the service defines a set of API operations (see Actions). To grant permissions for these API operations, Amazon Lex defines a set of actions that you can specify in a policy. For example, for the Amazon Lex Intent resource, the following actions are defined: CreateIntent and CreateIntentVersion. Performing an API operation can require permissions for more than one action.

The following are the most basic policy elements:

  • Resource – In a policy, you use an Amazon Resource Name (ARN) to identify the resource to which the policy applies. For more information, see Amazon Lex Resources and Operations.

  • Action – You use action keywords to identify resource operations that you want to allow or deny. For example, depending on the specified Effect, lex:bBot either allows or denies the user permissions to perform the Amazon Lex CreateBot operation.

  • Effect – You specify the effect of the action that occurs when the user requests the specific action—this can be either allow or deny. If you don't explicitly grant access to (allow) a resource, access is implicitly denied. You can also explicitly deny access to a resource. You might do this to make sure that a user cannot access the resource, even if a different policy grants access.

  • Principal – In identity-based policies (IAM policies), the user that the policy is attached to is the implicit principal. For resource-based policies, you specify the user, account, service, or other entity that you want to receive permissions. This applies to resource-based policies only. Amazon Lex doesn't support resource-based policies.

To learn more about IAM policy syntax and descriptions, see AWS IAM Policy Reference in the IAM User Guide.

For a table showing all of the Amazon Lex API actions, see Amazon Lex API Permissions: Actions, Resources, and Conditions Reference.

Specifying Conditions in a Policy

When you grant permissions, you use the IAM policy language to specify the conditions under which a policy should take effect. For example, you might want a policy to be applied only after a specific date. For more information about specifying conditions in a policy language, see Condition in the IAM User Guide.

AWS provides a set of predefined condition keys for all AWS services that support IAM for access control. For example, you can use the aws:userid condition key to require a specific AWS ID when requesting an action. For more information and a complete list of AWS-wide keys, see Available Keys for Conditions in the IAM User Guide.

Note

Condition keys are case sensitive.

Amazon Lex provides additional condition keys that you can include in Condition elements in an IAM permissions policy. The following table shows the Amazon Lex condition keys that apply to Amazon Lex resources.

Amazon Lex Policy Condition Keys

Amazon Lex Condition Key Description Value Type Permission
lex:associatedIntents

Scopes the set of intents that can be used when creating or modifying the definition of a bot.

Array of strings

lex:PutBot

lex:associatedSlotTypes

Scopes the set of slot types that can be used when creating or modifying the definition of a slot type.

Array of strings

lex:PutIntent

lex:ChannelType

Scopes the type of bot channel association that a user can create, get, or delete.

String

lex:CreateBotChannelAssociation

lex:DeleteBotChannelAssociation

lex:GetBotChannelAssociation

Example Policy: Using Condition Keys

The following example shows how to use condition keys in Amazon Lex IAM permissions policies.

Example 1: Grant Permission to Create Bots Using the OrderPizza Intent

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{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "lex:PutBot" "Resource": [ " *" ], "Condition": { "ForAllValues:StringLike": { "lex:associatedIntents": [ "OrderPizza" ] } } } ] }