# RPC **What is RPC (Remote Procedure Call) Node?** RPC Node enables applications to make calls to functions or procedures on Blockchain and retrieve information without dealing with the underlying complexities of communication protocols and network topology. The primary purpose of an RPC Node is to provide a mechanism for communication between different decentralized applications, systems, and services. This enables the creation of distributed applications, where the application logic is spread across multiple systems, communicating with each other through the RPC Node. **What are RPC API?** RPC APIs is a collection of methods for dApps to communicate with Blockchain by invoking processes or functions on remote systems. When a client application uses RPC, it sends a request to the Blockchain without revealing the client’s server information, instructing it to perform a specific function or procedure. After that, the server runs the requested function and returns the result to the client dApps. #### Websocket WebSocket endpoint provides support for Pub/Sub API as well as JSON-RPC filter support. Additionally, the regular JSON-RPC API is also supported over a WebSocket connection and documented for each JSON-RPC call. All examples in this reference section uses `wscat`, but will work with any tool that supports the WebSocket protocol. Some tools you can use for making these requests. [wscat](https://github.com/websockets/wscat) [Advanced Rest Client](https://install.advancedrestclient.com/install) Websocket subscription requests should include the WS host in the WebSocket API url. `wscat -c wss://ws-mainnet.uniultra.xyz` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.u2u.xyz/services/rpc.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.