Turn text into speech without a voice-platform contract
Text-to-speech across every voice model on one endpoint, billed per thousand characters in USDC. No seat licence, no monthly minimum, no API key.
What it does
Send the text, a model and a voice; the audio comes back in the response. A voices endpoint on the same path lists what each model can speak with. The card prices a thousand characters of input on each model, which is the unit the payment layer meters — a longer text costs proportionally more, quoted before it is synthesised.
The flash-tier models are built for real-time voice agents and are the cheapest on the card; the higher tiers trade latency for expressiveness. Sound effects have their own endpoint and their own page.
The call
One endpoint, priced in dollars before it runs and settled in USDC. No API key and no account — the request pays for itself.
POST /api/v1/audio/speech
Host: blockrun.aiWhy per call
No seat, no minimum, no contract per vendor. Each request is quoted in dollars before it runs and settles on-chain, so an agent can pay for its own work without a human holding a credit card. How the payment works →
Questions
How is speech priced?
Per thousand characters of input text, at the rate shown for each voice model below, quoted before the call runs.
Which languages are supported?
It varies by model — the multilingual voices cover dozens of languages, and the catalog lists what each one supports.
Is there a latency-optimised option?
Yes. The flash-tier models are built for real-time voice agents and are the cheapest on the card.
Do I need a subscription?
No. Each request pays for itself in USDC; there is nothing to cancel.