Quiz · Nervous System

A short knowledge check. Answers are hidden behind callouts so you can self-grade after answering.

1. How is the Nervous System different from Hands?

Hands change an external system: one capability, one target, one action. A Nervous System senses, communicates, and coordinates across many participants: many messages, event-driven, many-to-many. They share the same posture (provider-neutral, identity-bound, adapter-backed) but solve different problems.

2. Name the semantic message types the transport carries and what each one means.

  • observation — something is observed (sensor data, telemetry).
  • event — something happened (a state transition others may react to).
  • command — a request to perform an action on a specific target.
  • delegation — a Pico asks another Pico to carry out a mission.
  • result — the outcome of a command, delegation, or mission.
  • presence — a Pico is reachable on the transport right now.

3. Why is the Pico Agent Transport provider-neutral, and where does EMQX/MQTT fit?

So that Picos depend on stable message semantics rather than a specific broker or protocol. EMQX/MQTT is a candidate implementation / adapter of the transport — one of several possible implementations (alongside A2A, in-process buses, and future transports). Replacing the transport means swapping the adapter, not rewriting Pico rules or messages.

4. Why must Pico identity be independent of MQTT client IDs, broker sessions, and hostnames?

Infrastructure identifiers may change on every reconnect, scale operation, or Pod rescheduling. Pico identity must not. Binding authorization, evidence, or memory to an infrastructure identifier would break as soon as the infrastructure changed and would let two different Picos accidentally share an identity across reconnects.

5. What does “a valid broker session must not imply authorization” mean?

Broker authentication answers “is this client permitted to open this connection and publish to this topic?” That is a transport concern. Open Engineering authorization answers “is this Pico permitted to observe, command, or delegate this capability in this context?” Being allowed to publish to a topic does not automatically permit the capability the topic represents.

6. Why is discovery treated as a first-class Pico capability rather than a broker feature?

A Pico should be able to determine which peers exist, which are currently available (presence), what capabilities they advertise, and under what constraints — without hard-coding a peer list and without depending on a specific broker’s discovery extension. The transport carries discovery messages; Open Engineering owns the meaning of “this Pico advertises capability X.”

7. Why does an incoming message not automatically become long-term memory?

Delivery is a communication concern. Classification and retention are cognitive concerns owned by the Pico’s rules and memory. The Pico decides whether each message is transient, an observation, an event, a mission input, or evidence. Collapsing delivery and memory would either flood the Pico with noise or lose evidence that must be retained.

8. In this wave, is EMQX/MQTT a runnable dependency of the lesson?

No. EMQX/MQTT is illustrative only in this wave. No exercise, lab step, or verification command provisions or connects to a broker, opens an MQTT connection, or requires any broker account, TLS certificate, username, password, or API token. Every runnable check operates on local YAML using the provider-neutral message vocabulary. The optional follow-up shows the adapter mapping without running it.

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