Iodine voices in Vapi, with nothing to host.
Vapi’s custom voice calls a URL for every line your assistant speaks. Iodine answers that URL directly, so you paste it into the assistant and you’re done.
- 0 servers to run
- 8–48 kHz audio at the rate Vapi asks for
- $0.45 an hour of speech
How it works
- 01
Pick a voice
Choose one from the voice library, or clone your own.
- 02
Point Vapi at Iodine
Set the assistant’s voice to custom voice with Iodine’s URL and your key.
- 03
Call it
Every line is generated and streamed back as Vapi plays it.
"voice": {
"provider": "custom-voice",
"server": {
"url": "https://api.iodine.dev/v1/vapi/tts?voice=katie&model=v2",
"headers": { "Authorization": "Bearer io_live_YOUR_KEY" },
"timeoutSeconds": 20
}
}What you get
Nothing to deploy
Iodine serves Vapi’s custom voice protocol itself. There’s no adapter for you to host.
Learn more ›Phone-ready audio
Audio comes back at exactly the sample rate Vapi asks for, from 8 kHz for phone lines up to 48 kHz.
Learn more ›Your own voices
Use a cloned voice by its vc_ id in the URL, private to your account.
Learn more ›Same price
Billed by the length of audio, like every Iodine request. Failed requests cost nothing.
Learn more ›
What it costs
10,000 calls a month, with the assistant speaking for two minutes in each.
20,000 minutes of speech on Iodine $150.00
The same at ElevenLabs v4 Turbo's published price $800.00
At Iodine’s pay-as-you-go prices. Other providers at their published pay-as-you-go rates; see the price comparison.
Questions
In the server headers as Authorization: Bearer, in the server secret, or in a Vapi custom credential that sets the same header.
Yes. Set a fallbackPlan in the assistant and Vapi switches to it if a request fails.
8000, 16000, 22050 and 24000 Hz, which Vapi uses, plus 44100 and 48000.
Start building with Iodine.
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