The P1 live gate had to insert MQTT driver config directly via SQL: DriverConfigModal and
DeviceModal both fell through to "No typed config form for driver type Mqtt" with no raw-JSON
fallback, so broker host/port/TLS/credentials were unauthorable from the AdminUI. Task 12 built
the *tag* editor; these are the driver + device surfaces.
MqttDriverForm authors the whole MqttDriverOptions connection surface (host/port/clientId,
TLS + CA pin, credentials, protocol version/clean-session/keep-alive, connect timeout, reconnect
backoffs, mode, maxPayloadBytes, and the Plain sub-object). The Sparkplug sub-object stays P2 —
a marked placeholder mirroring MqttTagConfigEditor's stub, with any existing sparkplug keys
preserved untouched.
The connection is authored on the DRIVER, not the device — unlike Modbus/S7/OpcUaClient and
contrary to what docs/drivers/Mqtt.md said. DriverDeviceConfigMerger merges a device's keys up
only when the driver has exactly ONE device, so a device-authored broker connection vanishes
silently the moment a second device is added. MqttDeviceForm is therefore informational (the
GalaxyDeviceForm shape) and round-trips DeviceConfig verbatim; it flags legacy connection keys
left on a device by a pre-form deployment, because those still win via merge-up.
Serialization goes through the ONE shared MqttJson.Options instance (Task 9's decision), never a
fifth per-form copy — pinned by an assertion that an ordinal-only reader CANNOT bind the emitted
blob, and by extending the fleet-wide DriverPageJsonConverterTests guard to resolve a form's
serializer from an explicit external-instance registry when it has no _jsonOpts field. Dropping
the converter from MqttJson.Options reddens 3 tests and leaves the symmetric round-trip green —
the Task 9 lesson, reproduced.
RawTags is stripped from the emitted blob (the deploy artifact owns it) and unknown top-level
keys survive a load->save. Validation mirrors the driver's own [Range] bounds inline, and
ToOptions() additionally clamps, so an ignored error still cannot persist a
connectTimeoutSeconds:0 driver-brick. A non-blank clientId raises the P1 live-gate warning
inline (fixed ids make redundant pair nodes evict each other while both report Healthy).
AdminUI 761/761 green (was 730), TWAE-clean; Driver.Mqtt 266/266 green.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty
92ba120964