> This page is for Agent Handler.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.merge.dev/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.merge.dev/_mcp/server.

# Carbon Voice

> Carbon Voice generic MCP server on Agent Handler. Send and manage Carbon Voice voice messages and conversations.

> **Generic MCP server**
>
> Carbon Voice builds and hosts this MCP server. Agent Handler proxies your agent's calls to it, so you get the same auth, [tool access controls](/merge-agent-handler/administer/managing-tool-access), and [audit trail](/merge-agent-handler/observe/audit-trail) you get on a Merge Connector. The tool surface itself comes from Carbon Voice.

Send and manage Carbon Voice voice messages and conversations.

|                    |                                                        |
| ------------------ | ------------------------------------------------------ |
| **Type**           | Generic MCP server, hosted by Carbon Voice             |
| **Server URL**     | `https://mcp.carbonvoice.app`                          |
| **Authentication** | OAuth                                                  |
| **Tool surface**   | Defined by Carbon Voice                                |
| **Vendor docs**    | [github.com](https://github.com/PhononX/cv-mcp-server) |

## Authentication

Carbon Voice authenticates over OAuth. Your end user approves access in Carbon Voice's own consent screen during [Magic Link](/merge-agent-handler/build/authentication/magic-link), and Agent Handler holds the token.

## Available tools

Tools on a generic MCP server are defined by Carbon Voice, not by Merge, so the list changes when Carbon Voice changes it. Agent Handler discovers the current tools when the connection is made and re-discovers them on each resync, which means your agent always sees what the server actually exposes today.

To see the tools available right now, connect Carbon Voice in the dashboard and open its Connector page, or read [Carbon Voice's own MCP documentation](https://github.com/PhononX/cv-mcp-server).

## How this differs from a Merge Connector

Merge Connectors are written and tested by Merge against the vendor's REST API. Merge owns the tool names, the input schemas, the error messages, and the regression tests, so the surface stays stable and the tool descriptions are tuned for agents.

A generic MCP server is the vendor's own. You get whatever the vendor ships, on the vendor's release schedule. Agent Handler still handles credential storage, OAuth, tool policy, and audit logging identically, so the governance story is the same either way.

See [Connectors overview](/merge-agent-handler/connectors/overview) for the full comparison.

Next: [Connect a Connector](/merge-agent-handler/build/authentication/magic-link)