Post: MQTT wait_for_trigger value_template doesn't filter — three layers of HA template semantics

[clarkbw]

New post from today's Poseidon-cutover lesson (agent-lessons.md, 2026-06-11): the HA ask-roundtrip wait that "matched the reply's trace_id" for two days and had never filtered anything.

The arc, all trace-verified live today:

1. Layer 1: MQTT trigger value_template is a payload transformer, not a filter — without a payload: key nothing is compared and the trigger fires on every message. The trace_id check never filtered; one-producer topic made it invisible until interim says showed up and the puck spoke "Let me check the pilot book." as the answer.
2. Layer 2: payload: "True" matched nothing — templates render native types, boolean True ≠ string "True".
3. Layer 3: explicit sentinel strings still matched nothing — script variables aren't in scope in the per-message value_template render. Fun wrinkle: the script docs say variables are passed to the trigger, and that's true only at setup (topic/payload templates). I cite the actual mqtt/trigger.py lines showing the per-message render gets payload only.
4. Fix: bare trigger + repeat/until loop — conditions DO see script variables. Includes the wait.trigger is none timeout escape and a note that the timeout becomes per-message.

Gotchas section carries the three lessons (negative-case verification, shared-topic traffic as a breaking change, per-context template semantics incl. a summary table) plus one short paragraph on the assist_satellite.announce mid-session kill + interim: true skip — flagged as a candidate for its own post later.

Privacy check: no hosts/IPs/paths; topic names are the ones already public in naturali-agents; daemon referenced generically with an org link.

Worth a verify pass on: the trace_id generation snippet in the Problem section is illustrative, not our literal line; and the docs-vs-source framing in Attempt 2 — I quote dev-branch code, line shapes could drift.

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