Cocall.ai MCP: Outbound Phone Calls with Real-Time Human Escalation

Cocall.ai is a new MCP (Model Context Protocol) tool that gives Claude an outbound phone line. You provide a phone number, recipient identity, and an objective — the agent places the call using a full-duplex speech-to-speech model (not a cascade of STT, LLM, TTS). If the agent hits a question it can't answer mid-call, it pauses and sends you the specific question in your Claude session, keeping the conversation flowing on hold. It can also navigate IVR menus and hand the call back to you entirely.

Key Features

• Full-duplex speech-to-speech: Uses a single speech-to-speech model instead of separate STT → LLM → TTS stages.
• Mid-call question escalation: When uncertain, the agent stops, pings you in Claude with the exact question, and waits for your answer before proceeding.
• IVR navigation: Can handle automated phone menus.
• Call handoff: Can transfer the call to you live.
• Caller ID: After phone number verification, your number appears as the caller.
• Live monitoring & recordings: Web app lets you listen to calls live, download recordings, and view transcripts.

How to Add It to Claude

Follow the setup instructions at cocall.ai/docs/claude.

Intended Use Cases

The creator built it for real-estate and manufacturing firms where outbound calls are common but unstructured (follow-ups, meeting scheduling, delivery chasing). Existing frameworks like VAPI, Retell, and Bland focus on inbound workflows (support, marketing). This tool targets outbound calls that need on-demand human backup.

Technical Stack

Backend written in Bun, built spec-first using the OpenSpec workflow. The UI was designed in Claude Design, refined in Claude Web, and final implementation in Claude Code.

Subreddit thread: r/ClaudeAI