# Extensibility in WooCommerce Blocks These documents are all dealing with extensibility in the various WooCommerce Blocks. ## Checkout Block | Document | Description | | ---------- | ---------- | [Payment Method Integration](./payment-method-integration.md) | Information about implementing payment methods. [Checkout Flow and Events](./checkout-flow-and-events.md) | All about the checkout flow in the checkout block and the various emitted events that can be subscribed to. [Available Filters](./available-filters.md) | All about the filters that you may use to change values of certain elements of WooCommerce Blocks. [Exposing your data in the Store API.](./extend-rest-api-add-data.md) | Explains how you can add additional data to Store API endpoints. [Available endpoints to extend with ExtendRestAPI.](./available-endpoints-to-extend.md) | A list of all available endpoints to extend. [Adding an endpoint to ExtendRestAPI.](./extend-rest-api-new-endpoint.md) | A step by step process for contributors to expose a new endpoint via ExtendRestApi. [Slots and Fills.](./slot-fills.md) | Explains Slot Fills and how to use them to render your own components in Cart and Checkout. [Available Slot Fills.](./available-slot-fills.md) | Available Slots that you can use and their positions in Cart and Checkout. [IntegrationInterface](./integration-interface.md) | The `IntegrationInterface` class and how to use it to register scripts, styles, and data with WooCommerce Blocks.