DeepSeek Harness developer preview: composable plugins and traceable runs
DeepSeek’s open developer-preview harness makes models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and UI replaceable plugins, then records each run in an append-only event log that supports resume, fork, search, and replay.
Its Cordis kernel handles plugin lifecycle and dependencies. Standard mode is a full coding agent; Code mode lets the model orchestrate tool calls through a TypeScript SDK; Minimal mode is a two-tool benchmark environment; Creator mode exposes runtime inspection and preset authoring. The preview is early and Node/TypeScript-based, and HN commenters questioned how much it differs from existing harnesses, but the traceable trajectory and explicit composition model are useful ideas for harness engineering.