AI phone agents with integrated audio understanding, model routing, and voice optimization
Stage
Startup
Not given
Founded
Not given
Not given
Based in
Not given
US
Pricing model
Free
Paid
Pricing
Free, no subscription or in-app purchases. Each key can send up to 300 messages per hour.
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
Live progress cards on lock screen and Dynamic Island
Completion and failure notifications
Approval and denial prompts
Metrics display on lock screen
Stop button for running tasks
Native formatting on lock screen
No account or login required
One-line setup integration
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
No computer installation, SDK or MCP server needed—agents use curl over HTTPS
Completely free with no subscription, ads or in-app purchases
Works with multiple AI platforms including Claude Code, Codex and Cursor
High-rate message delivery with 300 messages per hour per key
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
Monish
ThunderPhone