A code-level walkthrough of the open-source agent harness built by DeepSeek AI — real symbols, service keys, config rows and events, read from the pinned checkout.
0.1.0-rc.547f9438One command, 219 packages — what the harness is, and the “everything is a plugin” philosophy behind it.
Profiles & bundles, the Cordis extension system, the boot flow, and the agent lifecycle.
The agent loop, session management, scopes, system-prompt assembly, model selection and tool presentation.
Context sources, compaction, goals & goal rounds, plan mode, and human interactions.
Shell, filesystem, code runtime, web & search, skills, jobs & schedule, spill, MCP and LSP.
Subagents, workflow & Ralph, and session query with log export.
Sandbox architecture, the Landlock native runtime, filesystem policies, permissions and credentials.
The LLM layer, DeepSeek provider, API gateway & proxy, settings, storage, hooks and ACP.
Client runtime, UI modules, the web app, schema forms and localization.
SDK protocol/client/server, typert, testing, invariants, CI and vendored libraries.
The full package index with versions, glossary, and a map of official docs.