Best non-mathy framing I found: a context is a bag of services (ctx.tools, ctx.llm, ctx.sessions...), a plugin is an object that claims some of those keys and registers reversible effects on mount - unload unwinds them. Dispatch has four modes: emit (observe), waterfall (around-middleware, next() to delegate), parallel, serial. And the "everything is a plugin" claim is literal: model adapter, tool registry, session log and the agent loop itself are plugins.

One consequence we liked: since plugins are just Cordis bundles, the same registry can be exposed to any MCP-speaking agent. We built a small MCP server that searches the dsh-plugin topic, inspects bundles, and can install/run them (catalog plane works without dsh installed). github.com/bobleer/deepseek-harness-plugin-mcp