Build AI voice agents on your own stack

Voicelo runs AI voice agents that answer inbound calls and place outbound ones, on your own Twilio numbers or SIP trunk, using your own Deepgram, ElevenLabs and OpenRouter keys. This is the reference for building, testing and integrating with it.

How it fits together

Everything in Voicelo hangs off one object: the Agent. An agent has a system prompt, an opening line, a voice engine, and — optionally — tools it can call mid-call, a knowledge base it can search, and an appointment calendar it can book into. You point a phone number or a campaign at an agent, and every call that reaches it runs the same configuration.

The pieces, and where they’re documented

Agents: Prompt, opening line, merge fields, appointment booking, human transfer. See Agents.
Voice engines: Three ways an agent can listen, think and speak — pick per agent. See Voice engines.
Tools: HTTP calls an agent makes before, during or after a call — your own endpoint or a connected integration. See Tools.
Knowledge base: Reference material an agent searches on demand instead of carrying in every prompt. See Knowledge base.
Campaigns & leads: Who gets called, and the outbound list that dials them in order. See Campaigns & leads.
Calls & recordings: What comes back from every call: transcript, recording, AI-scored summary. See Calls & recordings.
Webhooks: Real-time, signed events your own backend can subscribe to. See Webhooks.
Evals: Scripted conversations that grade an agent's replies and tool calls before you ship a prompt change. See Evals.
API: Everything above, over HTTP — the dashboard is itself just a client of it. See API reference.

Bring your own keys

Voicelo does not resell minutes. You connect your own Twilio account (or a SIP trunk), your own Deepgram key for speech, your own ElevenLabs key for voices, and your own OpenRouter key to pick a language model — all from Settings in the dashboard. Voicelo orchestrates the call between them; what a minute costs is whatever your providers charge, with no per-minute markup on top.

Where to start

New to Voicelo? The Quickstart walks through connecting a number and making your first call in a few minutes. Integrating your own backend against it? Go straight to the API reference.

NextQuickstart