Inworld acquires Ultravox to add a voice-agent platform to its speech stack

Ultravox co-founder Zach Koch says the team will keep developing the product; built-in Inworld voices have already moved to Realtime TTS-2 at no extra cost.

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Primary source: X

Why it matters

Inworld has added the agent platform layer to its speech-model and inference business. Existing Ultravox customers get an immediate voice upgrade, while the acquisition gives Inworld a path to bring more of its stack into developers' applications.

Inworld acquires Ultravox to add a voice-agent platform to its speech stack — Ultravox co-founder Zach Koch says the team will keep developing the product; built-in Inworld voices have already moved to Realtime TTS-2 at no extra cost.

Inworld AI acquired Ultravox, the platform for building real-time voice agents, bringing Ultravox team members into Inworld as it expands from speech models and infrastructure into the software developers use to build agents. Inworld announced the deal on X and detailed it in a company blog post dated September 30th, 2026.…

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