---
url: https://canary.warp-drive.io/guides/the-manual/reactivity/misc.md
description: >-
  Learn how WarpDrive exposes cached documents, resources, and fields reactively
  through PolarisMode or LegacyMode records, with pluggable signals so Ember or
  React can integrate.
---

# Reactive Access to Cached Data

In addition to request and cache management, WarpDrive provides a reactive access
layer for data in the cache.

Data in the cache is conceptualized as belonging to one of three forms

* **Documents** - the response to a request
* **Resources** - a unique cacheable entity within the response to a request
* **Fields** - the data for an individual property on a resource

Each form of data can be accessed and managed reactively through one of two modes

* *(upcoming, default in v6)* [PolarisMode](./../schemas/resources/polaris-mode.md)
* *(current, default in v5)* [LegacyMode](./../schemas/resources/legacy-mode.md)

These modes are interoperable. The reactive object (record) for a resource in PolarisMode can relate to
a record in LegacyMode and vice-versa. This interoperability is true whether the record in LegacyMode is
a ReactiveResource or a Model.

These reactive primitives use fine-grained signals-based reactivity. The specific implementation used is pluggable and can be integrated with any implementation or
even multiple at once.

For Ember, we use glimmer's implementation of `Signal` (`@tracked`) and `Computed` (`@cached`), though the integration does not have to be an implementation of signals
at all! For instance, `react` could be integrated by utilizing [useSyncExternalStore](https://react.dev/reference/react/useSyncExternalStore) in place of signals and subscribing to all potential changes via the notification manager.