> **Experimental**
>
> `@aws-cdk/aws-bedrock-agentcore-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# PolicyEngine

Container that manages Cedar authorization policies associated with gateways.

PolicyEngine enables deterministic authorization control for Bedrock agents,
allowing fine-grained access control to tools and actions via Cedar policy language.

Extends: Construct › Resource › PolicyEngineBase › PolicyEngine
Implements: IPolicyEngine, IResource, IGrantable, IEnvironmentAware, IPolicyEngineRef, IConstruct, IDependable

- Stability: [Experimental](/cdk/api/stability.html)
- CloudFormation: [`AWS::BedrockAgentCore::PolicyEngine`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-bedrockagentcore-policyengine.html)
- L1 type: [`CfnPolicyEngine`](/cdk/api/v2/docs/aws-cdk-lib.aws_bedrockagentcore.CfnPolicyEngine.html)
- Source: [`lib/policy/policy-engine.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0-alpha.0/packages/@aws-cdk/aws-bedrock-agentcore-alpha/lib/policy/policy-engine.ts#L76)

## Example

```ts
const importedEngine = agentcore.PolicyEngine.fromPolicyEngineAttributes(
  this,
  "ImportedEngine",
  {
    policyEngineArn: "policy-engine/my-engine-id",
  }
);

const importedPolicy = agentcore.Policy.fromPolicyAttributes(
  this,
  "ImportedPolicy",
  {
    policyArn: "my-policy-arn",
    policyEngine: importedEngine,
  }
);

// Grant permissions to the imported policy
const role = new iam.Role(this, "PolicyRole", {
  assumedBy: new iam.ServicePrincipal("lambda.amazonaws.com"),
});

importedPolicy.grantRead(role);
```

## Initializer

```ts
new PolicyEngine(scope: Construct, id: string, props?: PolicyEngineProps)
```

## Construct Props

- `description`: string — Optional description for the policy engine.

  **Default:** No description

  Maximum 4,096 characters.

- `kmsKey`: [IKey](/cdk/api/v2/docs/aws-cdk-lib.aws_kms.IKey.html) — Custom KMS key for encryption.

  **Default:** AWS owned key

  [disable-awslint:prefer-ref-interface]

- `policyEngineName`: string — The name of the policy engine.

  **Default:** Auto-generated unique name

  Valid characters: a-z, A-Z, 0-9, _ (underscore)
  Must start with a letter, 1-48 characters
  Pattern: ^[A-Za-z][A-Za-z0-9_]*$

- `tags`: { [key: string]: string } — Tags for the policy engine.

  **Default:** No tags

  Maximum 50 tags.

## Properties

- `description`: string — The description of the policy engine.

- `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) (required) — The environment this resource belongs to.

  For resources that are created and managed in a Stack (those created by
  creating new class instances like `new Role()`, `new Bucket()`, etc.), this
  is always the same as the environment of the stack they belong to.

  For referenced resources (those obtained from referencing methods like
  `Role.fromRoleArn()`, `Bucket.fromBucketName()`, etc.), they might be
  different than the stack they were imported into.

- `grantPrincipal`: [IPrincipal](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IPrincipal.html) (required) — The principal to grant permissions to.

- `kmsKey`: [IKey](/cdk/api/v2/docs/aws-cdk-lib.aws_kms.IKey.html) — The KMS key used to encrypt the policy engine.

- `node`: [Node](/cdk/api/v2/docs/constructs.Node.html) (required) — The tree node.

- `policies`: [Policy](/cdk/api/v2/docs/@aws-cdk_aws-bedrock-agentcore-alpha.Policy.html)[] (required) — Get the list of policies added to this policy engine.

  Returns an array of Policy constructs that were added using addPolicy().
  This allows you to iterate over all policies associated with this engine.

- `policyEngineArn`: string (required) — The ARN of the policy engine resource.

- `policyEngineId`: string (required) — The ID of the policy engine.

- `policyEngineName`: string (required) — The name of the policy engine.

  [disable-awslint:attribute-tag]

- `policyEngineRef`: [PolicyEngineReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_bedrockagentcore.PolicyEngineReference.html) (required) — A reference to this PolicyEngine resource.

- `PROPERTY_INJECTION_ID`: string (required) (static) — Uniquely identifies this class.

- `stack`: [Stack](/cdk/api/v2/docs/aws-cdk-lib.Stack.html) (required) — The stack in which this resource is defined.

- `tags`: { [key: string]: string } — Tags applied to this policy engine resource.

  **Default:** No tags applied

## Methods

- `addPolicy(id: string, options: AddPolicyOptions): Policy` — Add a policy to this policy engine. Convenience method that creates a Policy construct with this engine as the parent.

  **Automatic Sequential Chaining**: By default, policies are automatically chained
  sequentially to prevent concurrent creation issues with the AWS Bedrock AgentCore
  service. Each new policy will depend on the previous policy added to this engine.

  This ensures policies are created one at a time, avoiding "Resource stabilization
  failed" errors that occur with concurrent policy operations.

  **Parameters**

  - `id` — - Unique identifier for the policy construct.
  - `options` — - Options for creating the policy.

  **Returns:** The created Policy construct

- `applyCrossStackReferenceStrength(strength: ReferenceStrength): void` — Override the cross-stack reference strength for this resource.

  When set, any cross-stack reference to this resource will use the specified
  mechanism instead of the global default determined by the
  `@aws-cdk/core:defaultCrossStackReferences` context key. This is useful for
  selectively weakening specific references to avoid the "deadly embrace" problem
  without changing the app-wide default.

  **Parameters**

  - `strength` — - The reference strength to use for this resource.

- `applyRemovalPolicy(policy: RemovalPolicy): void` — Apply the given removal policy to this resource.

  The Removal Policy controls what happens to this resource when it stops
  being managed by CloudFormation, either because you've removed it from the
  CDK application or because you've made a change that requires the resource
  to be replaced.

  The resource can be deleted (`RemovalPolicy.DESTROY`), or left in your AWS
  account for data recovery and cleanup later (`RemovalPolicy.RETAIN`).

- `fromPolicyEngineAttributes(scope: Construct, id: string, attrs: PolicyEngineAttributes): IPolicyEngine` (static) — Creates a PolicyEngine reference from an existing policy engine's attributes.

  **Parameters**

  - `scope` — - The construct scope.
  - `id` — - Identifier of the construct.
  - `attrs` — - Attributes of the existing policy engine.

  **Returns:** An IPolicyEngine reference to the existing policy engine

- `grant(grantee: IGrantable, ...actions: string[]): Grant` — Grants IAM actions to the IAM Principal.

  [disable-awslint:no-grants]

  **Parameters**

  - `grantee` — - The IAM principal to grant permissions to.
  - `actions` — - The actions to grant.

  **Returns:** An IAM Grant object representing the granted permissions

- `grantEvaluate(grantee: IGrantable): Grant` — Grants permissions to evaluate policies at runtime (data plane operations).

  This is the primary permission needed by Gateway execution roles to evaluate
  authorization decisions during agent requests. Grant this to roles that need
  to call AuthorizeAction or PartiallyAuthorizeActions at runtime.

  [disable-awslint:no-grants]

  **Parameters**

  - `grantee` — - The IAM principal to grant evaluation permissions to.

  **Returns:** An IAM Grant object representing the granted permissions

- `grantEvaluateForGateway(grantee: IGrantable, gateway: IGateway): Grant` — Grants the full set of permissions required for a gateway execution role to use this policy engine, correctly scoped to both the policy engine and gateway ARNs.

  Per the AWS docs:
  - `GetPolicyEngine` → policy engine ARN only
  - `AuthorizeAction` + `PartiallyAuthorizeActions` → policy engine ARN **and** gateway ARN

  [disable-awslint:no-grants]

  **Parameters**

  - `grantee` — - The IAM principal (gateway execution role) to grant permissions to.
  - `gateway` — - The gateway that will use this policy engine [disable-awslint:prefer-ref-interface].

  **Returns:** A combined IAM Grant representing all granted permissions

- `grantRead(grantee: IGrantable): Grant` — Grants read permissions on the PolicyEngine (data plane).

  This grants runtime read access to policy engine configuration. Use this for
  monitoring, observability, or read-only administrative roles that need to inspect
  policy engine settings at runtime.

  [disable-awslint:no-grants]

  **Parameters**

  - `grantee` — - The IAM principal to grant read permissions to.

  **Returns:** An IAM Grant object representing the granted permissions

- `isConstruct(x: any): boolean` (static) — Checks if `x` is a construct.

  Use this method instead of `instanceof` to properly detect `Construct`
  instances, even when the construct library is symlinked.

  Explanation: in JavaScript, multiple copies of the `constructs` library on
  disk are seen as independent, completely different libraries. As a
  consequence, the class `Construct` in each copy of the `constructs` library
  is seen as a different class, and an instance of one class will not test as
  `instanceof` the other class. `npm install` will not create installations
  like this, but users may manually symlink construct libraries together or
  use a monorepo tool: in those cases, multiple copies of the `constructs`
  library can be accidentally installed, and `instanceof` will behave
  unpredictably. It is safest to avoid using `instanceof`, and using
  this type-testing method instead.

  **Parameters**

  - `x` — Any object.

  **Returns:** true if `x` is an object created from a class which extends `Construct`.

- `isOwnedResource(construct: IConstruct): boolean` (static) — Returns true if the construct was created by CDK, and false otherwise.

- `isResource(construct: IConstruct): boolean` (static) — Check whether the given construct is a Resource.

- `metric(metricName: string, dimensions: { [key: string]: string }, props?: MetricOptions): Metric` — Return the given named metric for this policy engine.

  By default, the metric will be calculated as a sum over a period of 5 minutes.
  You can customize this by using the `statistic` and `period` properties.

  **Parameters**

  - `metricName` — The name of the metric.
  - `dimensions` — Additional dimensions for the metric.
  - `props` — Optional metric configuration.

- `metricAuthorizationLatency(props?: MetricOptions): Metric` — Return a metric measuring the authorization latency for this policy engine.

  This metric represents the time taken to evaluate authorization policies.

  **Parameters**

  - `props` — Optional metric configuration.

- `metricAuthorizations(props?: MetricOptions): Metric` — Return a metric containing the total number of authorizations for this policy engine.

  This metric tracks all authorization requests processed by the policy engine.

  **Parameters**

  - `props` — Optional metric configuration.

- `metricDeniedRequests(props?: MetricOptions): Metric` — Return a metric containing the number of denied authorization requests for this policy engine.

  This metric tracks authorization requests that were explicitly denied by policies.

  **Parameters**

  - `props` — Optional metric configuration.

- `metricErrors(props?: MetricOptions): Metric` — Return a metric containing the number of errors during authorization for this policy engine.

  This metric tracks errors encountered during policy evaluation.

  **Parameters**

  - `props` — Optional metric configuration.

- `toString(): string` — Returns a string representation of this construct.

- `with(...mixins: IMixin[]): IConstruct` — Applies one or more mixins to this construct.

  Mixins are applied in order. The list of constructs is captured at the
  start of the call, so constructs added by a mixin will not be visited.
  Use multiple `with()` calls if subsequent mixins should apply to added
  constructs.