The fence the Engine in a Box / Walking the Grid tutorial calls when each cell of the oculus_fence boundary fires. Lives here so the tutorial's POST /run round-trips to a real /api/oculus/fences/nita-buy/execute endpoint instead of 404'ing.
The fence is intentionally minimal — it acknowledges the purchase and echoes the line item back. Oculus's pipeline executor stamps a session_id into metadata on the response automatically; the wanderland boundary surfaces it on its output so downstream cells (or trace replay) can pin a particular run.
A future variant can persist Nita's bag on this node for stateful demos. The current shape stays stateless so repeat POST /run invocations are idempotent.
H1 slug intentionally matches the node slug — see things-that-are-silly-as-fuck for why an apostrophe in the H1 (Nita's Grocery Walk) breaks fence resolution.
{
"error": "item is required"
}