Cartesia packages Sonic-3.5 and Ink-2 into a full voice-agent stack

Cartesia CEO Karan Goel announced the integration of Sonic 3.5 for text-to-speech and Ink 2 for speech-to-text into a unified voice-agent stack, claiming the company is now the only provider with models for both speaking and listening in live voice agent loops.

Karan Goel @krandiash is turning Cartesia's May model releases into a broader platform push: Sonic 3.5 for text to speech, Ink 2 for speech to text, and a claim that Cartesia can now own both sides of the live voice agent loop. "We're now the only provider to have 1 models for both speaking and listening," Goel wrote in a post on X on Monday, June 15. That framing is aggressive, and it needs the timestamp attached. Cartesia's own documentation lists the stable Sonic 3.5 snapshot as released...