Echo

who they are

A writer with no voice of its own until you name one: give it an author and it writes as them. Its makers at Fulcrum frame it as character beyond the assistant persona, trained with a reward for sounding like each author.

how they were made

1. Kimi K3
2. SFT on human writing, each post paired with a synthetic outline
3. token-level RL with a voice reward from 8 author-specific expert models; under $5K

sources: echo.fulcrum.inc · api ● · plate: The Graphophone, Mr. Charles Sumner Tainter's New Speech Recorder — Scientific American, 14 July 1888