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Voice for AI Agents

Give your AI voice agents a phone number, and the human contact center to hand off to. Most voice-AI tools build the bot and the media pipe but stop there: there’s no human queue to escalate into, no supervisor, no reporting, and you’re renting the phone network from someone else. SIP.IO provides the telephony, the media streaming, and the native contact center your agents escalate into with full context: OpenAI-API-compatible, SDK-driven.

The handoff is the hard part

An AI voice agent works until the caller needs a human; then “what happens after escalation” decides the experience. SIP.IO makes the handoff native:

  1. The AI agent answers a phone number and streams audio to your STT → LLM → TTS stack.
  2. When it needs to escalate, it enqueues the caller into a skills-based ACD queue with context.
  3. A human agent picks up via presence, supervisors watch the live wallboard, and the whole interaction lands in reporting.

What you get

  • Real phone numbers. Inbound DIDs and outbound, global inventory, per-country caller-ID.
  • Media streaming: stream call audio to your model; play synthesized speech back.
  • The human layer: ACD queues, agents, business-hours routing, voicemail, and a supervisor wallboard, the contact center the bot-builders don’t have.
  • Developer surface. Clean SDKs, a full OpenAPI spec, and an OpenAI-API-compatible interface.
  • Secure & global: TLS/SRTP, anycast-global edge, multi-tenant white-label.

Why not just a voice-AI tool?

Voice-AI agent platforms are great at the bot. But when you need a human queue, a supervisor, business-hours routing, compliance reporting, or to resell the whole thing under your brand, you hit a wall. SIP.IO is the platform around the bot: bring your own models, and get the telephony + contact center as one. See how this plays out against specific platforms: SIP.IO vs Vapi, SIP.IO vs Bland AI, SIP.IO vs Retell AI.

FAQ

How do I give my AI agent a phone number? Provision a DID, route it to your agent, stream audio to your STT→LLM→TTS pipeline, and drive the call via the API/SDKs.

Can it hand off to a human? Yes. It enqueues the caller into a native ACD queue with context so a human continues seamlessly.

OpenAI-API compatible? Yes: an OpenAI-API-compatible surface plus SDKs.

Start free · Programmable Voice API · Cloud Contact Center