id: oe.lab.hello-two-picos
title: Hello Two Picos
level: intermediate
duration: 60m
prerequisites:
  - oe.lab.hello-pico-on-manifold
  - oe.course.manifold
  - oe.course.kubernetes
teaches:
  - Two named Picos hosted by one Manifold RuntimeEnvironment
  - Wrangler-declared Channel plus explicit producer→consumer wiring
  - Single-event, single-reaction two-Pico interaction
  - Runtime Observation attributed to an upstream Pico via wiring
produces:
  - hello-two-picos
referenced_by:
  - oe.course.manifold
constructive_role: realization
realizes:
  - oe.course.manifold
realization_pattern: two-picos-on-manifold-single-channel
runtime_substrate: kubernetes
runs_on: manifold-on-kubernetes
interaction_topology: downloads/topology.yaml
control_surfaces:
  - python-cli
depends_on:
  - oe.lab.hello-pico-on-manifold
validated_by:
  - "walkthrough.qmd Step 5 — kubectl wait pod/hello-consumer-pico Ready"
  - "walkthrough.qmd Step 7 — downloads/verify.sh applies the producer Pico, then confirms one 'hello.greeting' emitted and one Observation consumed"
  - "walkthrough.qmd Step 8 — captured build/hello-two-picos/observation.txt contains the reaction line"
lifecycle_state: operational
evidence:
  - check: "walkthrough.qmd Step 5 — kubectl wait pod/hello-consumer-pico Ready"
    path: walkthrough.qmd
    description: "Rendered walkthrough Step 5 shows the Manifold-hosted consumer Pico Pod becoming Ready before the producer runs."
  - check: "walkthrough.qmd Step 7 — downloads/verify.sh applies the producer Pico, then confirms one 'hello.greeting' emitted and one Observation consumed"
    path: downloads/verify.sh
    description: "Shipped verify.sh applies the producer Pico Pod, waits for both single-shot Pods to Succeed, and asserts the producer 'sent' line and the consumer Observation line both appear."
  - check: "walkthrough.qmd Step 8 — captured build/hello-two-picos/observation.txt contains the reaction line"
    path: walkthrough.qmd
    description: "Rendered walkthrough Step 8 captures observation.txt — the single Observation the consumer Pico produced in reaction to the producer Pico's emitted event."
feedback:
  - observation: "Keeping the topology at two Picos, one Channel, and one explicit producer→consumer wiring makes the multi-Pico runtime story auditable end-to-end: the Wrangler-declared wiring, the single event on the wire, and the single Observation attributing it back to the producer Pico all line up one-for-one."
    about: hello-two-picos
    refines: oe.course.manifold
    observation_source: manifold-on-kubernetes