Inception Labs makes Mercury Voice generally available

On Tuesday Inception Labs made Mercury Voice generally available to enterprise customers. It is a diffusion language model, which refines many tokens in parallel instead of one at a time, tuned for the part of a voice agent that sits between speech-to-text and text-to-speech.

The claims

• median time to first answer token of 320 ms (750 ms at the 95th percentile)
• 128K context and three reasoning-effort settings
• an OpenAI-compatible endpoint that drops into LiveKit, Pipecat, Vapi and Retell
• launch pricing of $0.20 per million input tokens and $0.75 per million output, half the list price, which Inception puts at about $0.009 per minute of conversation

The caveat

The 320 ms figure and the claim that it beats GPT-6 Luna, GLM-5.3-Flash and Gemini 3.5 Flash-Lite are both measured on Inception's own test set, model only, with network time subtracted. The benchmark win was published with no per-benchmark numbers.

Why it matters

This is the first serious attempt to put a reasoning diffusion model inside the sub-500 ms window of a live phone agent. It's a candidate worth testing, not a proven swap: a lab result is not the same as picking up your phone.