> ## Documentation Index
> Fetch the complete documentation index at: https://docs.alpha.isaree.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP servers

> Secure adapters that let your AI talk to external systems — hospital databases or personal tools alike.

**MCP** stands for Model Context Protocol. You can think of an MCP server as a highly secure, standardized plug socket.

The [Primary Agent](/isa/primary-agent) uses [tool calling](/concepts/tool-calling) to reach external systems — your hospital's Electronic Medical Record, or a personal tool like Notion, Google Calendar, or Gmail — through an MCP server. It cannot connect directly. An MCP server is a small piece of software that acts as a translator and a security guard between the AI and whatever system it's connected to.

<Info>
  MCP servers run outside Isa — requests pass through them on their way to the external system. If you are using a cloud-connected MCP server, that data leaves your device. See [On-device vs cloud](/concepts/on-device-vs-cloud) for the full picture.
</Info>

On the Mac, Isa can also connect to MCP servers running locally on the same machine — requests to a local server stay on your Mac. On iPhone and iPad, only remote MCP servers are available, because iOS doesn't let apps run local server processes. See [Local vs. remote MCP servers](/concepts/local-vs-remote-mcp-servers) for how the two kinds differ and what your Mac needs before a local server can run.

## How it works in practice

You ask the [Primary Agent](/isa/primary-agent) to pull up the latest lab results for a patient in Bed 4.

The Primary Agent does not have direct access to the hospital's private lab database. Instead, it sends a formal request to the hospital's **MCP server**. The MCP server checks who is asking, verifies that you have the right permissions, translates the request into a language the lab system understands, retrieves the results, and hands them securely back to the Primary Agent.

If the Primary Agent tries to ask for something it should not — like the records of a patient not under your care — the MCP server blocks the request.

## Why it matters for clinicians

* **Security:** MCP servers ensure that the Primary Agent can only access the exact data it is permitted to see, keeping patient information compliant with hospital policies.
* **Easy integration:** Existing software does not have to be rebuilt. Plug an MCP server in front of it, and the old system can talk to modern AI — whether it is a hospital EMR or a personal tool like Notion or Calendar.
* **Shared access:** Any MCP server registered on the [Community Hub](https://alpha.isaree.ai/en/community) can be installed into Isa, giving you access to a growing set of tools — both clinical systems and personal services.

## Next

<CardGroup cols={3}>
  <Card title="Local vs. remote MCP servers" icon="laptop" href="/concepts/local-vs-remote-mcp-servers">
    See where an MCP server runs and what that means for your data.
  </Card>

  <Card title="Add an MCP server" icon="server" href="/hub/add-mcp-server">
    Register an MCP server in the Community Hub and install it in Isa.
  </Card>

  <Card title="Tool calling" icon="wrench" href="/concepts/tool-calling">
    Understand how the Primary Agent invokes external functions through MCP.
  </Card>
</CardGroup>