AI phone agents with integrated audio understanding, model routing, and voice optimization
Stage
Not given
Not given
Founded
Not given
Not given
Based in
US
US
Pricing model
Freemium
Paid
Pricing
Open Source: free and self-hosted. Free: $0/month hosted plan with up to 5 members. Scale: $20 per user per month. Enterprise: Custom annual contract.
Cost-plus pricing: customers pay vendor list prices for models and voice plus hosting (15% of vendor costs, 0.5¢ to 2¢ per minute) plus company margin (17-25%). Lean calls cost from 2.0¢/min (1.18¢ vendors + 0.50¢ hosting + 0.35¢ margin). Receptionist calls cost 4.7¢/min (3.36¢ vendors + 0.50¢ hosti
Key features
Tool call interception for all agent frameworks
Automatic approval rules to prevent fatigue
AI judge for complex rule evaluation
Works with LangGraph, CrewAI, Mastra, Claude Agent SDK and more
Open Agent Approval Protocol for framework independence
Self-hosted or cloud-hosted deployment options
Custom permission policies and organization controls
Multi-model architecture running multiple transcription and language models per call
Zeus AI agent that builds, tests and tunes voice agents automatically
Simulated call testing before live deployment
Live call monitoring and observability
A/B testing and automated fix suggestions
Integration wizard for CRM, VoIP and business software
Client portals for managing multiple agents
Knowledge base integration for agent grounding
Outbound campaigns with CSV upload and scheduling
What makes it different
Framework-agnostic: works with any AI agent through the open Agent Approval Protocol
No vendor lock-in: open source spec and SDKs let you swap providers without rewriting agents
Comprehensive audit trail for accountability and compliance
Meets reviewers where they work with multi-platform notifications
Policy-based routing to eliminate approval bottlenecks
Cost-plus pricing with no margin markup pass-through when vendor prices drop
Fully agentic Zeus AI that handles entire lifecycle from creation to optimization
Multi-model architecture for superior audio understanding vs 3-step pipelines
Starts at 2¢/min, cheaper than competitors and call center labor
withHuman
ThunderPhone