Architecture: everything is a plugin

Goal

Map DeepSeek Harness to three layers so you can reason about upgrades and plugin risk.

Layer 1 — Cordis kernel

Cordis loads, unloads, and wires dependencies. It does not hard-code “how to edit a file” or “how to call a model”. Think of it as the plugin runtime.

Layer 2 — Capabilities as plugins

Public materials describe capabilities such as: model adapters, tools, skills, sessions, sandboxes, storage, agent loops, schedulers, and even UI — each provided by plugins that collaborate through Cordis services and events.

Layer 3 — Compose in configuration

Developers select, replace, or extend capabilities without editing DeepSeek Harness source. That is what “everything is a plugin” means in practice: composition lives in config, not forks.

Why teams care

• Swap a model provider without rewriting the UI.
• Disable dangerous tools in Minimal mode for evals.
• Keep session logging consistent while experimenting with new plugins.

Mental model vs MCP-centric tools

Other coding agents may emphasize MCP servers. DSH emphasizes npm / Cordis plugins. See our compare page for workflow fit — not hype.

Next

Study the four run modes so you pick Standard vs Minimal before installing extra plugins.