diff --git a/opencode/decisions.yaml b/opencode/decisions.yaml
index 089c5cd..c782c94 100644
--- a/opencode/decisions.yaml
+++ b/opencode/decisions.yaml
@@ -32,3 +32,22 @@ notes:
       - nest_snapshot
     pin: true
     status: active
+  - id: 2026-08-06-octoprint-automation-playroom-light
+    date: 2026-08-06
+    title: OctoPrint automation (playroom light + basement heat) pending — via MQTT/OctoMQTT
+    decision: "Built-in OctoPrint integration is broken here (AssertionError device_id is not
+      None; no printer entities). Chosen route: OctoMQTT plugin, trigger on
+      octoPrint/event/PrintStarted. Pending automation: when print starts, turn on
+      light.playroom_light and set climate.basement to 22C."
+    rationale: Completed the built-in OctoPrint integration setup flow but HA logs show setup
+      errors for sensor/binary_sensor/button/camera/number platforms, so there is nothing
+      to trigger on. User chose the MQTT route and will configure the OctoMQTT plugin
+      later (printer is currently busy). Leave the broken OctoPrint entry alone until this
+      is resolved.
+    entities:
+      - light.playroom_light
+      - climate.basement
+    integrations:
+      - octoprint
+      - mqtt
+    status: active