Integrate MCP

MCP is an open standard for securely connecting AI assistants to external data sources and tools. In Zero Runtime AI Agents, attach MCP servers to auto-discover services, databases, and APIs. The agent picks and runs the right tools and turns results into natural responses.

How It Works

MCP tools are automatically discovered and made available to your agent, which intelligently chooses which tools to use based on user requests. When a user asks for information that requires external data, the agent will:

Identify the need

Detect that the user’s request requires external data.

Select tools

Choose the appropriate tools from the available MCP servers.

Execute

Run the tools with the relevant parameters.

Respond

Process the results and provide a natural language response.

This integration allows your voice agent to access real-time data and external services while maintaining a natural conversational flow.

Transport Methods

Zero Runtime supports two transport methods for MCP servers.

Transport	Communication	Best For
STDIO	Direct process communication with local Python scripts	Custom tools and functions, server-side integrations
HTTP (Streamable HTTP or SSE)	Network-based communication with external MCP services	Third-party integrations, remote MCP servers

Example

Pass MCP servers to the agent via the mcp_servers parameter. Use MCPServerStdio for local scripts and MCPServerHTTP for remote services.

import sys
from zrt import Agent, MCPServerStdio, MCPServerHTTP

class MyVoiceAgent(Agent):
    def __init__(self, pipeline):
        super().__init__(
            agent_id="assistant",
            instructions="You are a helpful assistant with access to real-time data.",
            pipeline=pipeline,
            mcp_servers=[
                # STDIO - local script
                MCPServerStdio(
                    command=sys.executable,
                    args=["mcp_stdio_example.py"],
                ),
                # HTTP - remote service
                MCPServerHTTP(
                    url="https://your-mcp-service.com/api/mcp",
                    headers={"Authorization": "Bearer <token>"},
                ),
            ],
        )

The agent auto-discovers every tool exposed by each server and chooses among them at runtime, so you don’t register tools individually.

Server options

`MCPServerStdio` (local process)

Parameter	Type	Description
`command`	`str`	Command to launch the server (e.g. `sys.executable` for Python).
`args`	`list[str]`	Arguments passed to the command (typically the server script path).
`env`	`dict[str, str]`	Extra environment variables for the server process.

`MCPServerHTTP` (remote service)

Parameter	Type	Description
`url`	`str`	URL of the remote MCP service (Streamable HTTP or SSE).
`headers`	`dict[str, str]`	HTTP headers to send (e.g. an `Authorization` bearer token).

The parameter names above are for the Python SDK. The JavaScript and Go SDKs use command + args (+ env) for STDIO and url + headers for HTTP. For example, MCPServerStdio('python', { args: [...] }) and MCPServerHTTP(url, { headers }) in JS, or &zrt.MCPServerStdio{Command, Args, Env} and &zrt.MCPServerHTTP{URL, Headers} in Go.

What’s Next

Function Tools

Add custom Python functions as tools.

RAG

Ground responses in a knowledge base.

References

Python

Examples

MCP Client

Consume tools from an MCP server.

SDK Reference

MCP

MCP in the Python API reference.

Get started

Modalities

Configure Pipeline

Tools and Capabilities

Turn Detection and Interruptions

Telephony Agents

Context Management

Observability and Monitoring

How It Works

Transport Methods

Example

Server options

`MCPServerStdio` (local process)

`MCPServerHTTP` (remote service)

What’s Next

Function Tools

RAG

References

Examples

MCP Client

SDK Reference

MCP

​How It Works

​Transport Methods

​Example

​Server options

​MCPServerStdio (local process)

​MCPServerHTTP (remote service)

​What’s Next

Function Tools

RAG

​References

​Examples

MCP Client

​SDK Reference

MCP

How It Works

Transport Methods

Example

Server options

`MCPServerStdio` (local process)

`MCPServerHTTP` (remote service)

What’s Next

References

Examples

SDK Reference