id: oe.lab.hello-pico-on-manifold
title: Hello Pico on Manifold
level: intermediate
duration: 60m
prerequisites:
  - oe.lab.hello-pico
  - oe.course.manifold
  - oe.course.kubernetes
teaches:
  - Manifold as a Kubernetes-hosted RuntimeEnvironment
  - Pico engine as an in-process Pico host
  - Wrangler channels and subscriptions (single-channel topology)
  - Single-event, single-response Pico behaviour
  - Runtime Observation captured as lab evidence
produces:
  - hello-world-pico-on-manifold
referenced_by:
  - oe.course.manifold
constructive_role: realization
realizes:
  - oe.course.manifold
realization_pattern: pico-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
validated_by:
  - "walkthrough.qmd Step 5 — kubectl wait pod/pico-engine Ready"
  - "walkthrough.qmd Step 7 — downloads/verify.sh sends one event and confirms one 'Hello, Pico!' response line"
  - "walkthrough.qmd Step 8 — captured build/hello-world-pico-on-manifold/observation.txt contains the response"
lifecycle_state: operational
evidence:
  - check: "walkthrough.qmd Step 5 — kubectl wait pod/pico-engine Ready"
    path: walkthrough.qmd
    description: "Rendered walkthrough Step 5 shows the Manifold-hosted Pico engine Pod becoming Ready."
  - check: "walkthrough.qmd Step 7 — downloads/verify.sh sends one event and confirms one 'Hello, Pico!' response line"
    path: downloads/verify.sh
    description: "Shipped verify.sh sends exactly one event onto the Wrangler-declared channel and asserts exactly one matching response line appears in the Pico engine's logs."
  - check: "walkthrough.qmd Step 8 — captured build/hello-world-pico-on-manifold/observation.txt contains the response"
    path: walkthrough.qmd
    description: "Rendered walkthrough Step 8 captures observation.txt — the single Observation the hosted Pico produced in response to the single event."
feedback:
  - observation: "Keeping the topology at one Pico and one Channel makes the runtime story auditable end-to-end: the Wrangler-declared subscription, the single event on the wire, and the single log line the Pico engine prints all line up one-for-one."
    about: hello-world-pico-on-manifold
    refines: oe.course.manifold
    observation_source: manifold-on-kubernetes