diff --git a/cue-ios/CueIOS/Models/Storage.swift b/cue-ios/CueIOS/Models/Storage.swift
index b6e29fc..4b4f04e 100644
--- a/cue-ios/CueIOS/Models/Storage.swift
+++ b/cue-ios/CueIOS/Models/Storage.swift
@@ -11,6 +11,7 @@ struct Session: Codable, FetchableRecord, MutablePersistableRecord {
     var startedAt: Date
     var label: String?
     var notes: String?
+    var firmwareSessionId: Int64?
 
     mutating func didInsert(_ inserted: InsertionSuccess) {
         id = inserted.rowID
@@ -24,6 +25,7 @@ struct Measurement: Codable, FetchableRecord, MutablePersistableRecord {
     var startedAt: Date
     var config: Data?
     var resultSummary: Data?
+    var espTimestamp: Int64?
 
     mutating func didInsert(_ inserted: InsertionSuccess) {
         id = inserted.rowID
@@ -89,19 +91,34 @@ final class Storage: @unchecked Sendable {
             }
         }
 
+        migrator.registerMigration("v2") { db in
+            try db.alter(table: "measurement") { t in
+                t.add(column: "espTimestamp", .integer)
+            }
+            try db.alter(table: "session") { t in
+                t.add(column: "firmwareSessionId", .integer)
+            }
+        }
+
         try migrator.migrate(dbQueue)
     }
 
     // MARK: - Sessions
 
-    func createSession(label: String? = nil) throws -> Session {
+    func createSession(label: String? = nil, firmwareSessionId: Int64? = nil) throws -> Session {
         try dbQueue.write { db in
-            var s = Session(startedAt: Date(), label: label)
+            var s = Session(startedAt: Date(), label: label, firmwareSessionId: firmwareSessionId)
             try s.insert(db)
             return s
         }
     }
 
+    func fetchSession(_ id: Int64) -> Session? {
+        try? dbQueue.read { db in
+            try Session.fetchOne(db, key: id)
+        }
+    }
+
     func fetchSessions() throws -> [Session] {
         try dbQueue.read { db in
             try Session.order(Column("startedAt").desc).fetchAll(db)
@@ -123,13 +140,43 @@ final class Storage: @unchecked Sendable {
         }
     }
 
+    func updateSessionLabel(_ id: Int64, label: String) throws {
+        try dbQueue.write { db in
+            try db.execute(
+                sql: "UPDATE session SET label = ? WHERE id = ?",
+                arguments: [label, id]
+            )
+        }
+    }
+
+    func sessionByFirmwareId(_ fwId: Int64) -> Session? {
+        try? dbQueue.read { db in
+            try Session
+                .filter(Column("firmwareSessionId") == fwId)
+                .fetchOne(db)
+        }
+    }
+
     // MARK: - Measurements
 
+    func measurementExists(sessionId: Int64, espTimestamp: Int64) -> Bool {
+        (try? dbQueue.read { db in
+            try Measurement
+                .filter(Column("sessionId") == sessionId)
+                .filter(Column("espTimestamp") == espTimestamp)
+                .fetchCount(db) > 0
+        }) ?? false
+    }
+
     func addMeasurement(
         sessionId: Int64,
         type: MeasurementType,
-        config: (any Encodable)? = nil
+        config: (any Encodable)? = nil,
+        espTimestamp: Int64? = nil
     ) throws -> Measurement {
+        if let ts = espTimestamp, measurementExists(sessionId: sessionId, espTimestamp: ts) {
+            throw StorageError.duplicate
+        }
         let configData: Data? = if let config {
             try JSONEncoder().encode(config)
         } else {
@@ -140,7 +187,8 @@ final class Storage: @unchecked Sendable {
                 sessionId: sessionId,
                 type: type.rawValue,
                 startedAt: Date(),
-                config: configData
+                config: configData,
+                espTimestamp: espTimestamp
             )
             try m.insert(db)
             return m
@@ -460,6 +508,7 @@ final class Storage: @unchecked Sendable {
 
 enum StorageError: Error {
     case notFound
+    case duplicate
     case parseError(String)
 }