# Context Servers

A Context Server is an experimental interface for defining simple, language-agnostic slash commands in Zed's [Assistant](./assistant.md). Context Servers allow you to extend Zed's Assistant to interface with external capabilities and systems in a language-agnostic way.

If slash commands allow you to extend the Assistant with new capabilities, Context Servers follow a simple protocol for registering and making use of those capabilities.

## Using a Context Server

To configure Zed to use a Context Server, add the command required to start the server to your [settings](../configuring-zed.md):

```json
{
  "experimental": {
    "context_servers": [
      {
        "id": "python_context_server",
        "executable": "python",
        "args": ["-m", "my_context_server"]
      }
    ]
  }
}
```

## Developing a Context Server

Context Servers are JSON-RPC servers communicating over stdio. Context Servers must comply with the [Model Context Protocol (MCP)](./model-context-protocol.md).

See [python-context-server](https://github.com/zed-industries/python-context-server) for a minimal working example.

Currently, Zed's client only implements a subset of the protocol required to support custom prompt insertions and manipulations. This is likely to be expanded in the future.

### Should you write a Context Server?

[Extensions](../extensions.md) are also capable of [adding slash commands to the Assistant](../extensions/slash-commands.md).

If your slash commands are already implemented in a language other than Rust, wrapping them in a Context Server implementation will likely be the fastest way to plug them into Zed.

An Extension should be preferred when:

- Your slash commands are implemented in WebAssembly-compatible Rust
- You want Zed to manage distribution of your slash commands
- You want to publish your slash commands