# IMergeStrategy

Interface for applying properties to a target using a specific strategy.

- Source: [`core/lib/mixins/property-merge-strategy.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/core/lib/mixins/property-merge-strategy.ts#L25)
- Type last changed: v2.242.0 · 10 Mar 2026

## Methods

- `apply(target: json, source: json, allowedKeys: string[]): void` — Apply properties from source to target for the given keys.

  **Parameters**

  - `target` — - The construct to apply properties to.
  - `source` — - The property values to apply.
  - `allowedKeys` — - Only properties whose names are in this list will be read from `source` and written to `target`.