# Reverse Invocation of the Dify Service

Plugins can request some of the services within the main Dify platform to enhance it's capabilities by reverse invocation.

### Callable Dify Modules

* [**App**](https://legacy-docs.dify.ai/plugins/schema-definition/reverse-invocation-of-the-dify-service/app)

  Plugins can access data from Apps within the Dify platform.
* [**Model**](https://legacy-docs.dify.ai/plugins/schema-definition/reverse-invocation-of-the-dify-service/model)

  Plugins can make reverse calls to LLM capabilities within the Dify platform, including all model types and features available on the platform, such as TTS, Rerank, etc.
* [**Tool**](https://legacy-docs.dify.ai/plugins/schema-definition/reverse-invocation-of-the-dify-service/tool)

  Plugins can request other tool-type plugins within the Dify platform.
* [**Node**](https://legacy-docs.dify.ai/plugins/schema-definition/reverse-invocation-of-the-dify-service/node)

  Plugins can request nodes within specific Chatflow/Workflow applications on the Dify platform.