DeepSeek's 'Black Whale' Surfaces: Harness Developer Preview Open-Sourced Under MIT — Everything Is a Plugin

On August 13, DeepSeek released the official V4 Pro model and the developer preview of DeepSeek Harness, open-sourced under the MIT license. Built on the Cordis plugin system, Harness treats every agent capability as a plugin and ships append-only session logs with full trajectory tracing.