MCP Servers

What is MCP?

Model Context Protocol (MCP) is a standard protocol for giving AI models access to tools. Instead of hard-coding capabilities into an LLM, MCP lets you connect external tool servers that the model can call during a conversation. izan.io uses MCP as its primary tool system.

Built-in Servers

These servers run entirely in your browser with no external dependencies:

General -- time/date queries, calculator, password generator, UUID generator
Domain Check -- domain availability lookups via RDAP and DNS-over-HTTPS

Built-in servers are automatically available and require no setup.

Adding Custom MCP Servers

You can connect any MCP-compatible server:

Go to Settings and scroll to Custom MCP Servers
Click Add and enter the server's URL
izan.io will connect and discover the server's available tools
Assign the server to one or more agents

This makes izan.io a great environment for MCP developers testing their own servers -- connect your local or deployed server and interact with its tools through a full chat interface.

CORS Handling

Browser security restrictions (CORS) can block direct connections to external MCP servers. izan.io handles this automatically:

First attempts a direct browser-to-server connection
If CORS blocks the request, it retries through the MCP proxy (an AWS Lambda relay)
The proxy only forwards the MCP protocol traffic -- it never sees your API keys or conversation data

Assigning Servers to Agents

You can assign MCP servers to agents in two ways:

From the agent edit panel, select which servers the agent should have access to
From Settings, manage server assignments across all agents

Only servers assigned to the active agent are connected during a chat session. Switching agents automatically disconnects unused servers and connects the relevant ones.