Runtime Core: Execute, Tools, Timelines

Runtime core (F1, F2, F15, F16)

Agents as backend jobs (F1)

Product entrypoints call AgentRuntime.execute — see src/chat/chat.service.ts — not a free-floating chatbot process.

Lab — track an order (F1–F2)

curl -s localhost:3060/api/support/chat \
  -H 'content-type: application/json' \
  -d '{"message":"Where is my package for ORD-1001?"}' | jq .

Expect a real lookupOrder / tracking path against the in-memory commerce store.

DemoLLM vs OpenAI

• Empty OPENAI_API_KEY → DemoLLM (fine for wiring labs)
• Set a key when you want realistic tool selection

Inspector + timeline (F15)

Open http://localhost:3060/__hazel. Correlate executionId with .hazel/timeline.jsonl (or configured timeline file). Lesson: /learn/agentic-development/observability-signals-for-agent-decisions.

Eval smoke (F16)

Meridian runs Jest / agent tests in-repo. Craft path: /learn/agentic-development/golden-tests-with-describe-agent and /guides/build-an-evaluation-harness.

Checkpoint C

Timeline (or response metadata) shows a real tool name from support-desk — not a CLI stub.