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

> Source: <https://runtimewire.com/article/cartesia-sonic-35-ink-2-voice-agent-benchmarks>
> Published: 2026-06-15 22:44:30+00:00

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...