Where it fits
Telephone carrier · Speech synthesis
Carrier minutes, phone-number rental and voice synthesis are separate cost components. A TTS setting does not purchase or bind a number.
Configure the connection
Configure your Telnyx carrier account and number binding separately from the assistant. The snippet selects TTS only; inbound routing needs carrier configuration too.
Assistant configuration fragment. Merge this into your assistant; select current model and voice IDs from your account before saving.
{
"pipeline_mode": "cascading",
"tts_provider": "telnyx",
"tts_voice": "YOUR_TELNYX_VOICE_ID"
}Keep provider secrets in workspace credentials. The public MCP provider matrix describes capabilities; it does not connect your provider account.
Test this boundary first
Call a test number in both directions, check audio and hangup behavior, then reconcile carrier records with APIFleet call logs.
Save a known working configuration and move one test route first. Inspect the call log before increasing traffic. Follow the staged migration guide.
Understand the bill
APIFleet adds $0.03 per connected AI minute, billed per second. Provider and carrier usage are additional. With your own keys, provider charges go directly to the provider. No monthly subscription or free call credits; prepaid top-ups start at $10.