Tianyi Cui
0000cdb2c2
A config agent with `resumeSessionId` set continues a persisted session
instead of starting a fresh `${id}-session-<uuid>`. The id is sourced from
an env var in cordis.yml, so the coding-agent demo can resume a prior
conversation without code changes. The resume is deferred until the
`sessionPersistence` backend loads (via ctx.inject) and is contained: a
missing/unreadable id logs a warning and starts no agent. Adds a real-API
resume e2e proving cross-process continuity through the JSONL backend.
dsh-agent-loop
THE concrete agent plugin: LoopAgent and the loop driver. Implements the Agent interface and drives the session/turn/step lifecycle.
This is the only package in the harness that contains concrete loop logic. Everything else is an abstract service or a plugin against extension seams — new behavior goes into plugins, not here.
Service: AgentLoop (ctx key: agentLoop)
Public API
ctx.agentLoop.create(id: string, options?: AgentOptions): LoopAgent— config-driven create: an agent on a fresh per-run session id${id}-session-<uuid>(no cwd). Used forcordis.yml-configured agents. The per-run uuid avoids colliding with the on-disk log a prior run materialized once a durable persistence backend is loaded; each run is a new session (a deliberate demo simplification — a real resume-or-create policy is a TODO). Disposed with the calling fiber.
AgentLoop also implements the AgentFactory seam and registers itself via ctx.agents.setFactory(this), so plugins create/resume agents through ctx.agents (the interface):
ctx.agents.create({ agentId, sessionId, meta?, agentOptions? })— programmatic create on a caller-suppliedsessionId(e.g. an ACP-generated id), NOT${id}-session.ctx.agents.resume({ agentId, resumeSessionId, agentOptions? })— load a persisted session viactx.sessionPersistence(RFC 009) and resume an agent on it. The live session id is the resumed id; turn numbering and derived history continue from the loaded log. Requires a session-persistence backend (NOT hard-injected — non-persistent demos still work;resumerejects with a clear error when persistence is absent).
Injected services
agents, sessions, llm, tools, systemPrompt — all five interface services.
Configuration (schemastery)
interface Config {
agents: Array<{
id: string // required
model?: string
systemPrompt?: string
}>
}
Agents listed in config are auto-created at startup.
Classes
LoopAgent— the concreteAgentimplementation. Owns the inbox (Inbox), the per-stepAbortController, and the loop driver. Everything observable happens through session events and theagent/*event taxonomy.Inbox— per-agent queued + steering FIFOs (enqueue,steer,drainQueued,drainSteering,waitForQueued).
Loop lifecycle (loop.ts)
One invocation of runLoop() drives one agent for its whole lifetime:
forever:
wait for queued messages (idle)
TURN (error-contained):
drain queued → 'turn/start' → session('user/message')
STEP loop:
drain steering
assembly = systemPrompt.assemble()
request = waterfall agent/request
stream llm.stream(request) → session('assistant/chunk')
message = waterfall agent/step-result
session('assistant/message')
each tool-call: session('tool/call') → tools.execute() → session('tool/result')
drain steering → session('steering/message')
cont = waterfall agent/turn-continuation
if !cont: break
session('turn/end')
await session/flush
re-enqueue leftover steering as queued
idle unless more queued
Error containment: a throwing plugin ends the turn, never the loop. Dispose mid-turn emits agent/status('disposed') and ends with reason disposed.
What is NOT here
Everything that goes beyond "call the model, run the tools, repeat" belongs to plugins listening on the event taxonomy:
- Hooks:
agent/request,agent/step-result,tools/execute,agent/turn-continuation - Compaction:
agent/request - Sandbox, permission, plan mode:
tools/execute - Sub-agents: TODO seam on
AgentLoop.create() - Persistence:
session/event+session/flush - UI:
agent/stream-chunk+agent/*events