CommunicationPublic source

Voice & Realtime MCP Server

Voice and real-time communication for AI agents — calls, transcription, sentiment analysis, IVR management, recordings, and call center analytics. 20 tools with Twilio, Vonage, and Deepgram backends.

Open the source Read the official guide ↗

What it gives an agent

A purpose-built capability behind one MCP connection.

The server owns its domain logic and publishes a tool contract an MCP client can discover. ADK-Rust can load that contract into an agent, normalize each schema for the chosen model provider, and keep the connection lifecycle outside the agent’s business logic.

Provides voice capabilities through a typed MCP contract.

Architecture

How Voice & Realtime MCP Server fits into an agent system.

The model never needs the implementation details or credentials of the system behind the server. It sees reviewed tool definitions. The MCP client handles discovery and calls, while the server keeps ownership of validation, policy, and communication with its domain system.

ADK-Rust agent

Chooses a capability from the reviewed tool catalog.

→

MCP client

Discovers schemas, sends calls, and receives typed content.

→

Voice & Realtime MCP Server

Validates the request and owns 20 documented tool contracts.

→

Domain system

Keeps the API, data, credentials, and business rules behind the server.

Connection: stdio · Server framework: ADK MCP SDK + rmcp

Voice & Realtime MCP Server architecture diagram from its official repository

Tool catalog

What can an agent ask Voice & Realtime MCP Server to do?

Each tool has a stable name, a human-readable purpose, and a JSON input contract discovered during MCP initialization. Risk classes come from the project’s registry manifest when one is available.

20 named tools

list_calls

List calls (filter: direction, status)

see documentation

get_call

Call details + recording + transcript

see documentation

initiate_call

Start outbound call

see documentation

transfer_call

Transfer active call

see documentation

end_call

Hang up active call

see documentation

schedule_call

Schedule future call

see documentation

get_transcript

Full transcript with speaker labels

see documentation

get_call_summary

AI summary + action items

see documentation

analyze_sentiment

Per-speaker sentiment breakdown

see documentation

search_transcripts

Search all transcripts by keyword

see documentation

get_ivr_menu

Get IVR menu tree

see documentation

update_ivr_menu

Update menu options/routing

see documentation

Governance

Understand the effect of every tool.

A server connection inherits the authority of its credentials and deployment environment. The declarations below come from this project’s README and MCP registry manifest; your application still decides which tools an agent receives and where approval is required.

20 see documentation

initiate_call — external_write: calls a real phone, costs money
delete_recording — destructive: cannot be undone (GDPR compliance)
update_ivr_menu — affects all incoming callers
transfer_call — affects live conversation

MCP surface

What the current documentation declares.

MCP can carry tools, resources, prompts, structured results, progress, cancellation, and long-running work. This record highlights the modern protocol features explicitly mentioned by this repository.

Cancellation

ADK MCP SDKrmcp

Install and connect

Follow the project’s documented starting point.

Install the server in the environment that owns its credentials and domain access. Add it to your MCP host, verify the discovered tools, and narrow the toolset before giving it to a production agent.

Install

cargo install mcp-voice

MCP client configuration

export TWILIO_ACCOUNT_SID="ACxxxxxxxx"
export TWILIO_AUTH_TOKEN="your-auth-token"
export TWILIO_PHONE_NUMBER="+1234567890"
export DEEPGRAM_API_KEY="dg-xxxxxxxx"
mcp-voice

Commands and configuration are extracted from the public README. Confirm prerequisites, environment variables, and release-specific options in the official documentation before deployment.

Official documentation

Continue with the project maintainers’ source of truth.

This page provides an approachable map of the server. The repository remains authoritative for exact schemas, prerequisites, configuration, examples, tests, releases, and security updates.

Overview ↗README.md Architecture ↗docs/assets/architecture.svg Issues and support ↗github.com issues

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