# Policy

The AWS::IAM::Policy resource associates an [inline](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#inline) IAM policy with IAM users, roles, or groups. For more information about IAM policies, see [Overview of IAM Policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/policies_overview.html) in the IAM User Guide guide.

Extends: Construct › Resource › Policy
Implements: IResource, IGrantable, IPolicy, IEnvironmentAware, IPolicyRef, IConstruct, IDependable

- CloudFormation: [`AWS::IAM::Policy`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-iam-policy.html)
- L1 type: [`CfnPolicy`](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.CfnPolicy.html)
- Source: [`aws-iam/lib/policy.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-iam/lib/policy.ts#L114)
- Type last changed: v2.224.0 · 13 Nov 2025

## Example

```ts
declare const postAuthFn: lambda.Function;

const userpool = new cognito.UserPool(this, 'myuserpool', {
  lambdaTriggers: {
    postAuthentication: postAuthFn,
  },
});

// provide permissions to describe the user pool scoped to the ARN the user pool
postAuthFn.role?.attachInlinePolicy(new iam.Policy(this, 'userpool-policy', {
  statements: [new iam.PolicyStatement({
    actions: ['cognito-idp:DescribeUserPool'],
    resources: [userpool.userPoolArn],
  })],
}));
```

## Initializer

```ts
new Policy(scope: Construct, id: string, props?: PolicyProps)
```

## Construct Props

- `document`: [PolicyDocument](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.PolicyDocument.html) — Initial PolicyDocument to use for this Policy.

  **Default:** An empty policy.

  If omited, any
  `PolicyStatement` provided in the `statements` property will be applied
  against the empty default `PolicyDocument`.

- `force`: boolean = false — Force creation of an `AWS::IAM::Policy`.

  Unless set to `true`, this `Policy` construct will not materialize to an
  `AWS::IAM::Policy` CloudFormation resource in case it would have no effect
  (for example, if it remains unattached to an IAM identity or if it has no
  statements). This is generally desired behavior, since it prevents
  creating invalid--and hence undeployable--CloudFormation templates.

  In cases where you know the policy must be created and it is actually
  an error if no statements have been added to it or it remains unattached to
  an IAM identity, you can set this to `true`.

- `groups`: [IGroup](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IGroup.html)[] — Groups to attach this policy to.

  **Default:** No groups.

  You can also use `attachToGroup(group)` to attach this policy to a group.

- `policyName`: string — The name of the policy.

  **Default:** Uses the logical ID of the policy resource, which is ensured to be unique within the stack.

  If you specify multiple policies for an entity,
  specify unique names. For example, if you specify a list of policies for
  an IAM role, each policy must have a unique name.

- `roles`: [IRole](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IRole.html)[] — Roles to attach this policy to.

  **Default:** No roles.

  You can also use `attachToRole(role)` to attach this policy to a role.

- `statements`: [PolicyStatement](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.PolicyStatement.html)[] — Initial set of permissions to add to this policy document.

  **Default:** No statements.

  You can also use `addStatements(...statement)` to add permissions later.

- `users`: [IUser](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IUser.html)[] — Users to attach this policy to.

  **Default:** No users.

  You can also use `attachToUser(user)` to attach this policy to a user.

## Properties

- `document`: [PolicyDocument](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.PolicyDocument.html) — The policy document.

- `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) — 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) — The principal to grant permissions to.

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

- `policyName`: string — The name of this policy.

- `policyRef`: [PolicyReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_iam.PolicyReference.html) — A reference to a Policy resource.

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

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

## Methods

- `addStatements(...statement: PolicyStatement[]): void` — Adds a statement to the policy document.

- `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`).

- `attachToGroup(group: IGroup): void` — Attaches this policy to a group.

- `attachToRole(role: IRole): void` — Attaches this policy to a role.

- `attachToUser(user: IUser): void` — Attaches this policy to a user.

- `fromPolicyName(scope: Construct, id: string, policyName: string): IPolicy` (static) — Import a policy in this app based on its name.

- `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.

- `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.