Everything is a plugin.
Every run is traceable.
Everything is a plugin
DeepSeek Harness is built on Cordis's plugin system. Plugins provide every agent capability, including models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and the UI. Cordis services and events let the plugins work together. Developers can select, swap, or extend any capability in configuration without changing the DeepSeek Harness source code.
Every run is traceable
Everything the model sees is recorded in an append-only session log: system prompts, reasoning, tool calls and results, subagent scheduling, and every context injection. In the Trajectory view, you can inspect these records by source. Resume, fork, search, and replay all operate on the same event stream.
Choose how your agent runs
Standard mode
Full coding agent with file editing, shell, file and web search, skills, planning, goals, subagents, and workflows.
Code mode
All Standard mode capabilities, with tools exposed through the Code Mode SDK so the model can combine multi-step operations in one TypeScript program.
Minimal mode
Two-tool coding agent with persistent bash and str_replace_editor, for benchmarking models in a minimal environment.
Creator mode
Built for creating custom agent presets: runtime inspection, plugin experiments, and preset-authoring guidance.