MCP | AgentDuet SDK

This guide shows how to integrate the AgentDuet SDK with the Model Context Protocol (MCP) so live speech agents can call structured tools over a shared tool surface during phone calls.

Sample: OmniBank phone servicing (authenticate, fees, escalate).

Demo caller: Ava Chen, card ending 4821.

What this integration provides

AgentDuet answers inbound calls and streams PCM to Gemini Live
Gemini Live declares tools from an MCP server’s list_tools result
Tool calls dispatch to the MCP server over stdio (call_tool)
Swap mcp_tools_server.py to change capabilities without touching call wiring

How the pieces fit

Layer	Owns
AgentDuet	Connector, answer/hangup, PCM in/out
Gemini Live	Speech-to-speech + function calls
MCP client (`main.py`)	Stdio connect, schema cleanup, dispatch
MCP server (`mcp_tools_server.py`)	Bank tools (auth, summary, waiver, escalate)

Prerequisites

Python 3.12+
AgentDuet API key and connector UUID from agentduet.com
Gemini API key

Step 1: Clone the sample

$ git clone https://github.com/AgentDuet/agentduet-samples.git
$ cd agentduet-samples/integrations/mcp/omnibank-servicing

Layout:

omnibank-servicing/
├── main.py               # AgentDuet + Gemini Live + MCP client
├── mcp_tools_server.py   # FastMCP bank tools (stdio)
├── requirements.txt
└── .env.example

Step 2: Install

$ python3.12 -m venv .venv
$ source .venv/bin/activate
$ pip install -r requirements.txt

The sample pins agentduet==1.0.0.

Step 3: Configure `.env`

$ cp .env.example .env

$ AGENTDUET_API_KEY=your-connector-api-key
$ AGENTDUET_CONNECTOR_UUID=your-connector-uuid
$ GEMINI_API_KEY=

Step 4: Run

$ python main.py

main.py spawns mcp_tools_server.py over stdio, loads tool declarations into Gemini Live, then waits for calls.

Call your AgentDuet number. Say you are Ava Chen, card ending 4821.

Ask / do	Expect
Give name + last 4	Agent spells back, then `authenticate_customer`
Ask about fees	Late fee $30 + interest$ 45.50 from tool result
Waive one fee	`process_fee_waiver` approves (within $50 cap)
Waive both fees	Refused or escalated (`record_escalation`)

Tools

Tool	Role
`authenticate_customer`	Match name + last 4; return fees and waiver limit
`get_account_summary`	Card, balance, outstanding fees
`process_fee_waiver`	Waive fees up to $50 total
`record_escalation`	Log supervisor handoff; return reference

How AgentDuet and MCP connect

On startup, the app opens an MCP stdio client to mcp_tools_server.py.
list_tools becomes Gemini FunctionDeclarations (JSON Schema keys Gemini rejects are stripped).
On each inbound call, AgentDuet answers and Gemini Live streams audio.
When the model emits a tool call, the app runs call_tool and returns the result with send_tool_response.
Hangup closes the Gemini session; the MCP server process stays up for the next call.