9b8fccc6f9
Seven ADRs capturing the why behind decisions already made: vendoring Cordis as source with a guarded manifest; the microkernel event taxonomy with one swappable concrete loop; event-sourced sessions with derived history and the append-before-emit ordering contract; the provider-neutral content-block vocabulary (and why not OpenAI/Anthropic shapes); the custom tool-schema DSL over schemastery; tool schemas living in the prompt assembly; and mechanical quality gates over prose guidelines (the agents-write-the-code rationale).
1.8 KiB
ADR 0002: Microkernel — extension via Cordis event taxonomy, one concrete loop
Status: accepted (2026-06-11)
Context
The product principle (see the 微内核Harness实现思路 design doc) is "everything is a plugin": hooks, /goal, /loop, dynamic workflows, compaction, sandboxing, permissions, UI, persistence, MCP, skills must all be writable as plugins without modifying the core. Candidate mechanisms considered: a purpose-built middleware stack (koa-compose style), an explicit phase state machine plugins can insert into, or Cordis's native event system.
Decision
Pure Cordis event taxonomy. The loop's extension seams are typed events with deliberate dispatch modes:
- waterfall (around-middleware) where plugins mutate or veto:
agent/request,agent/step-result,agent/turn-continuation,tools/execute,llm/stream,llm/generate,system-prompt/assemble. - emit (sync fire-and-forget) for notifications: turn/step boundaries, stream chunks, lifecycle, errors.
- parallel (awaited) for the one durability checkpoint:
session/flush.
The event vocabulary lives in interface packages (dsh-agent declares the
agent/* events); @deepseek-ai/dsh-agent-loop is the only concrete plugin and
is itself swappable — nothing outside it may depend on it.
Consequences
- Every MVP feature maps to a listener (the "plugin sanity checklist" in docs/architecture.md is the proof obligation, kept current).
- HMR and disposal come free: listeners and registrations are Cordis effects.
- Waterfall semantics (call
next()or short-circuit) are non-obvious and must be taught — documented in AGENTS.md and covered by composition tests. - The loop must be defensive: plugin exceptions are contained at turn level, steering from any seam is never stranded (regression-tested).