diff --git a/cgm_sensor_notes/cgm_sensor_notes.patch b/cgm_sensor_notes/cgm_sensor_notes.patch
new file mode 100644
index 0000000..45a8da7
--- /dev/null
+++ b/cgm_sensor_notes/cgm_sensor_notes.patch
@@ -0,0 +1,234 @@
+# ============================================================================
+# cgm_sensor_notes
+#
+# Reports Dexcom sensor states without reliable glucose to Nightscout as Note
+# treatments, for G7 and G5/G6: "CGM: sensorFailed", "CGM: questionMarks",
+# "CGM: warmup", "CGM: .unknown(23)" and so on.
+#
+# The kits decide and name everything. A reading is reported when the kit's
+# own hasReliableGlucose is false, and the note text is the kit's own name for
+# the state. No state table, titles or localizations live in the patch, so
+# nothing can drift from the kits, and every state a kit knows or learns is
+# covered. Lifecycle states such as warmup, stopped and session ended are
+# reported too, a few per sensor session.
+#
+# A state is reported once and stays quiet while it persists. A reading with
+# reliable glucose, or a new sensor session, clears the log, so a state that
+# returns after recovery is reported again.
+#
+# ISOLATION: the notes ride the CGM event pipeline Loop already has
+# (CGMManagerDelegate -> CgmEventStore -> RemoteDataServicesManager ->
+# NightscoutService), which owns persistence and upload retry. The Loop app
+# itself is untouched, and so is every .pbxproj: the patch adds no files and
+# edits four Swift files whose hook points are identical on main, dev and
+# next-dev, so one patch serves all three branches.
+#
+# A note is handed to the event store once: if it fails to store, or Nightscout
+# stays unreachable until the local cache purges it, that state is not
+# reported again until the sensor recovers. Same durability as Loop's own
+# sensor start events.
+#
+# Nothing here changes dosing, glucose handling or what the app displays.
+# ============================================================================
+Submodule CGMBLEKit contains modified content
+diff --git a/CGMBLEKit/CGMBLEKit/TransmitterManager.swift b/CGMBLEKit/CGMBLEKit/TransmitterManager.swift
+index 682d9dd..624e0eb 100644
+--- a/CGMBLEKit/CGMBLEKit/TransmitterManager.swift
++++ b/CGMBLEKit/CGMBLEKit/TransmitterManager.swift
+@@ -349,6 +349,15 @@ public class TransmitterManager: TransmitterDelegate {
+             }
+         }
+
++        if let event = CgmSensorStateReporter.event(for: glucose.state.sensorObservation,
++                                                    namespace: "DexTransmitter",
++                                                    sensorSessionStart: glucose.sessionStartDate,
++                                                    deviceIdentifier: transmitter.ID,
++                                                    date: glucose.readDate)
++        {
++            events.append(event)
++        }
++
+         // Filter out future-dated events
+         // Stopgap measure for the issue described in https://github.com/LoopKit/Loop/issues/2087
+         events = events.filter { event in
+@@ -547,6 +556,11 @@ extension CalibrationError: LocalizedError {
+ }
+
+ extension CalibrationState {
++    /// The kit's own name for the state is what gets reported.
++    var sensorObservation: CgmSensorObservation {
++        hasReliableGlucose ? .reliable : .unreliable(state: description)
++    }
++
+     public var localizedDescription: String {
+         switch self {
+         case .known(let state):
+Submodule G7SensorKit contains modified content
+diff --git a/G7SensorKit/G7SensorKit/G7CGMManager/G7CGMManager.swift b/G7SensorKit/G7SensorKit/G7CGMManager/G7CGMManager.swift
+index 3fdc27b..c30b20a 100644
+--- a/G7SensorKit/G7SensorKit/G7CGMManager/G7CGMManager.swift
++++ b/G7SensorKit/G7SensorKit/G7CGMManager/G7CGMManager.swift
+@@ -385,6 +385,17 @@ extension G7CGMManager: G7SensorDelegate {
+             state.latestReadingTimestamp = latestReadingTimestamp
+         }
+
++        if let event = CgmSensorStateReporter.event(for: message.algorithmState.sensorObservation,
++                                                    namespace: "G7CGMManager",
++                                                    sensorSessionStart: activationDate,
++                                                    deviceIdentifier: state.sensorID ?? "Dexcom G7",
++                                                    date: latestReadingTimestamp)
++        {
++            delegate.notify { delegate in
++                delegate?.cgmManager(self, hasNew: [event])
++            }
++        }
++
+         guard let glucose = message.glucose else {
+             updateDelegate(with: .noData)
+             return
+@@ -514,3 +525,12 @@ extension G7GlucoseMessage: GlucoseDisplayable {
+         }
+     }
+ }
++
++// MARK: - Sensor state reporting
++
++extension AlgorithmState {
++    /// The kit's own name for the state is what gets reported.
++    var sensorObservation: CgmSensorObservation {
++        hasReliableGlucose ? .reliable : .unreliable(state: description)
++    }
++}
+Submodule LoopKit contains modified content
+diff --git a/LoopKit/LoopKit/GlucoseKit/PersistedCgmEvent.swift b/LoopKit/LoopKit/GlucoseKit/PersistedCgmEvent.swift
+index 953f415..7d8a400 100644
+--- a/LoopKit/LoopKit/GlucoseKit/PersistedCgmEvent.swift
++++ b/LoopKit/LoopKit/GlucoseKit/PersistedCgmEvent.swift
+@@ -13,6 +13,7 @@ public enum CgmEventType: String {
+     case sensorEnd
+     case transmitterStart
+     case transmitterEnd
++    case sensorIssue
+ }
+
+ public struct PersistedCgmEvent {
+@@ -55,3 +56,102 @@ extension CgmEvent {
+         return PersistedCgmEvent(managedObject: self)
+     }
+ }
++
++// MARK: - Sensor state reporting
++
++/// What a single reading says about the sensor.
++public enum CgmSensorObservation: Equatable {
++    /// The reading carries glucose the kit itself considers reliable.
++    case reliable
++    /// The reading carries no reliable glucose; `state` is the kit's own name
++    /// for the sensor state behind that.
++    case unreliable(state: String)
++}
++
++/// Decides which sensor states become `CgmEventType.sensorIssue` events.
++///
++/// A state is reported when a reading carries no reliable glucose and the
++/// state differs from the last one reported, so a persisting state is reported
++/// once. A reliable reading or a new sensor session clears the log, so a state
++/// that returns after recovery is reported again. The log outlives the manager
++/// instance, so a relaunch during a persisting state stays quiet.
++public enum CgmSensorStateReporter {
++    private struct Log: Codable, Equatable {
++        var sensorSessionStart: Date?
++        var notedState: String?
++    }
++
++    private static let lock = NSLock()
++
++    /// The event to hand to the CGM manager delegate, if this reading's state
++    /// is due for a note.
++    ///
++    /// - Parameters:
++    ///   - observation: What `date`'s reading says about the sensor.
++    ///   - namespace: Distinguishes one CGM manager's log from another's.
++    ///   - sensorSessionStart: Start of the session the reading belongs to.
++    ///     A new session clears the log. Both Dexcom kits re-derive this from
++    ///     the phone's clock on every reading, so it carries transport jitter
++    ///     and is compared with a tolerance far below the gap between two real
++    ///     sessions.
++    ///   - deviceIdentifier: Sensor or transmitter identifier.
++    ///   - date: Timestamp of the reading.
++    public static func event(for observation: CgmSensorObservation,
++                             namespace: String,
++                             sensorSessionStart: Date?,
++                             deviceIdentifier: String,
++                             date: Date) -> PersistedCgmEvent?
++    {
++        lock.lock()
++        defer { lock.unlock() }
++
++        let key = "com.loopkit.LoopKit.CgmSensorStateReporter.\(namespace)"
++        var log = (UserDefaults.standard.data(forKey: key).flatMap {
++            try? JSONDecoder().decode(Log.self, from: $0)
++        }) ?? Log()
++
++        let previous = log
++
++        if let sensorSessionStart = sensorSessionStart, isNewSession(sensorSessionStart, from: log.sensorSessionStart) {
++            // The first date seen for a session is kept, so later readings
++            // compare against a fixed point and the jitter cannot accumulate.
++            log.sensorSessionStart = sensorSessionStart
++            log.notedState = nil
++        }
++
++        var event: PersistedCgmEvent?
++
++        switch observation {
++        case .reliable:
++            log.notedState = nil
++        case .unreliable(let state):
++            if state != log.notedState {
++                log.notedState = state
++                event = PersistedCgmEvent(date: date,
++                                          type: .sensorIssue,
++                                          deviceIdentifier: deviceIdentifier,
++                                          failureMessage: "CGM: " + state)
++            }
++        }
++
++        if log != previous, let data = try? JSONEncoder().encode(log) {
++            UserDefaults.standard.set(data, forKey: key)
++        }
++
++        return event
++    }
++
++    /// Whether `sensorSessionStart` belongs to a session other than the one
++    /// already being tracked.
++    ///
++    /// The tolerance absorbs the transport jitter both kits carry: each derived
++    /// start is the true start plus the delay before the phone processed the
++    /// message, so repeated readings of one session land within seconds of each
++    /// other, while two real sessions are separated by at least a warmup.
++    private static func isNewSession(_ sensorSessionStart: Date, from tracked: Date?) -> Bool {
++        guard let tracked = tracked else {
++            return true
++        }
++        return abs(sensorSessionStart.timeIntervalSince(tracked)) > .minutes(15)
++    }
++}
+Submodule NightscoutService contains modified content
+diff --git a/NightscoutService/NightscoutServiceKit/Extensions/PersistedCgmEvent.swift b/NightscoutService/NightscoutServiceKit/Extensions/PersistedCgmEvent.swift
+index 6c5915f..c8d332d 100644
+--- a/NightscoutService/NightscoutServiceKit/Extensions/PersistedCgmEvent.swift
++++ b/NightscoutService/NightscoutServiceKit/Extensions/PersistedCgmEvent.swift
+@@ -16,6 +16,11 @@ extension PersistedCgmEvent {
+         case .sensorStart:
+             let note = "SensorID: \(deviceIdentifier)"
+             return NightscoutTreatment(timestamp: date, enteredBy: source, notes: note, eventType: .sensorStart)
++        case .sensorIssue:
++            guard let failureMessage = failureMessage else {
++                return nil
++            }
++            return NightscoutTreatment(timestamp: date, enteredBy: source, notes: failureMessage, eventType: .note)
+             // NS does not have a transmitter start type event yet
+ //        case .transmitterStart:
+ //            let note = "TransmitterID: \(deviceIdentifier)"