refactor: migrate Gson serialization to kotlinx.serialization (#475)

* refactor: migrate Gson serialization to kotlinx.serialization

* fix(dto): resolve serializing Any? and Map<String, Any?> with JsonElement

* test(refactor): fix unit test issues under kotlinx.serialization and update nullable DTO defaults

* fix(chat): support flexible numeric and string decoding for message timestamps

* fix(chat): sequentialize cache loading to avoid overwriting network state

app/src/main/java/com/m57/hermescontrol/data/model/Achievement.kt

@@ -1,68 +1,73 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class AchievementsResponse(
     val achievements: List<Achievement>? = emptyList(),
-    @SerializedName("unlocked_count") val unlockedCount: Int = 0,
-    @SerializedName("discovered_count") val discoveredCount: Int = 0,
-    @SerializedName("secret_count") val secretCount: Int = 0,
-    @SerializedName("total_count") val totalCount: Int = 0,
-    @SerializedName("is_stale") val isStale: Boolean = false,
-    @SerializedName("generated_at") val generatedAt: Long? = null,
-    @SerializedName("scan_meta") val scanMeta: ScanMeta? = null,
+    @SerialName("unlocked_count") val unlockedCount: Int = 0,
+    @SerialName("discovered_count") val discoveredCount: Int = 0,
+    @SerialName("secret_count") val secretCount: Int = 0,
+    @SerialName("total_count") val totalCount: Int = 0,
+    @SerialName("is_stale") val isStale: Boolean = false,
+    @SerialName("generated_at") val generatedAt: Long? = null,
+    @SerialName("scan_meta") val scanMeta: ScanMeta? = null,
     val error: String? = null,
 )
 
+@Serializable
 data class ScanMeta(
     val status: ScanStatus? = null,
 )
 
+@Serializable
 data class ScanStatus(
     val state: String = "idle",
-    @SerializedName("started_at") val startedAt: Long? = null,
-    @SerializedName("finished_at") val finishedAt: Long? = null,
-    @SerializedName("last_error") val lastError: String? = null,
-    @SerializedName("last_duration_ms") val lastDurationMs: Long? = null,
-    @SerializedName("run_count") val runCount: Int = 0,
+    @SerialName("started_at") val startedAt: Long? = null,
+    @SerialName("finished_at") val finishedAt: Long? = null,
+    @SerialName("last_error") val lastError: String? = null,
+    @SerialName("last_duration_ms") val lastDurationMs: Long? = null,
+    @SerialName("run_count") val runCount: Int = 0,
 )
 
+@Serializable
 data class RecentUnlock(
     val id: String,
     val name: String,
-    val description: String?,
-    val category: String?,
-    val kind: String?,
-    val icon: String?,
+    val description: String? = null,
+    val category: String? = null,
+    val kind: String? = null,
+    val icon: String? = null,
     val unlocked: Boolean,
     val discovered: Boolean,
-    val state: String?,
-    val tier: String?,
-    val progress: Double?,
-    @SerializedName("next_tier") val nextTier: String?,
-    @SerializedName("next_threshold") val nextThreshold: Double?,
-    @SerializedName("progress_pct") val progressPct: Double?,
-    @SerializedName("unlocked_at") val unlockedAt: Long?,
-    val secret: Boolean?,
-    val criteria: String?,
+    val state: String? = null,
+    val tier: String? = null,
+    val progress: Double? = null,
+    @SerialName("next_tier") val nextTier: String? = null,
+    @SerialName("next_threshold") val nextThreshold: Double? = null,
+    @SerialName("progress_pct") val progressPct: Double? = null,
+    @SerialName("unlocked_at") val unlockedAt: Long? = null,
+    val secret: Boolean? = null,
+    val criteria: String? = null,
 )
 
+@Serializable
 data class Achievement(
     val id: String,
     val name: String,
-    val description: String?,
-    val category: String?,
-    val kind: String?,
-    val icon: String?,
+    val description: String? = null,
+    val category: String? = null,
+    val kind: String? = null,
+    val icon: String? = null,
     val unlocked: Boolean,
     val discovered: Boolean,
-    val state: String?,
-    val tier: String?,
-    val progress: Double?,
-    @SerializedName("next_tier") val nextTier: String?,
-    @SerializedName("next_threshold") val nextThreshold: Double?,
-    @SerializedName("progress_pct") val progressPct: Double?,
-    @SerializedName("unlocked_at") val unlockedAt: Long?,
-    val secret: Boolean?,
-    val criteria: String?,
+    val state: String? = null,
+    val tier: String? = null,
+    val progress: Double? = null,
+    @SerialName("next_tier") val nextTier: String? = null,
+    @SerialName("next_threshold") val nextThreshold: Double? = null,
+    @SerialName("progress_pct") val progressPct: Double? = null,
+    @SerialName("unlocked_at") val unlockedAt: Long? = null,
+    val secret: Boolean? = null,
+    val criteria: String? = null,
 )

app/src/main/java/com/m57/hermescontrol/data/model/ActionResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class ActionResponse(
     val archive: String? = null,
     val name: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/ActionStatusResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class ActionStatusResponse(
     val exit_code: Int? = null,
     val lines: List<String>? = null,

app/src/main/java/com/m57/hermescontrol/data/model/Attachment.kt

@@ -1,4 +1,5 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
 /**
  * Represents a file attached to a chat message.
@@ -9,6 +10,7 @@ package com.m57.hermescontrol.data.model
  * @param size File size in bytes
  * @param localPath Optional local file system path for direct access
  */
+@Serializable
 data class Attachment(
     val uri: String,
     val name: String,

app/src/main/java/com/m57/hermescontrol/data/model/CheckpointsResponse.kt

@@ -1,10 +1,13 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class CheckpointsResponse(
     val sessions: List<CheckpointSession>? = null,
     val total_bytes: Long? = null,
 )
 
+@Serializable
 data class CheckpointSession(
     val session: String? = null,
     val files: Int? = null,

app/src/main/java/com/m57/hermescontrol/data/model/Config.kt

@@ -1,22 +1,26 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
 
-import com.google.gson.JsonElement
-
+@Serializable
 data class RawConfigResponse(
-    val path: String?,
-    val yaml: String?,
+    val path: String? = null,
+    val yaml: String? = null,
 )
 
+@Serializable
 data class UpdateRawConfigRequest(
     val yaml_text: String,
     val profile: String? = null,
 )
 
+@Serializable
 data class ConfigSchemaResponse(
     val fields: Map<String, SchemaField>,
     val category_order: List<String>,
 )
 
+@Serializable
 data class SchemaField(
     val type: String,
     val description: String? = null,
@@ -24,6 +28,7 @@ data class SchemaField(
     val options: List<String>? = null,
 )
 
+@Serializable
 data class ConfigUpdateRequest(
     val config: Map<String, JsonElement>,
     val profile: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/ConnectionProfile.kt

@@ -1,7 +1,8 @@
 package com.m57.hermescontrol.data.model
-
+import kotlinx.serialization.Serializable
 import java.util.UUID
 
+@Serializable
 data class ConnectionProfile(
     val id: String = UUID.randomUUID().toString(),
     val name: String,

app/src/main/java/com/m57/hermescontrol/data/model/CredentialPoolResponse.kt

@@ -1,14 +1,18 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class CredentialPoolResponse(
     val providers: List<CredentialPoolProvider>? = null,
 )
 
+@Serializable
 data class CredentialPoolProvider(
     val provider: String? = null,
     val entries: List<CredentialPoolEntry>? = null,
 )
 
+@Serializable
 data class CredentialPoolEntry(
     val index: Int? = null,
     val label: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/CronJob.kt

@@ -1,17 +1,23 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
 
+@Serializable
 data class CronJobRepeat(
     val times: Int? = null,
     val completed: Int = 0,
 )
 
+@Serializable
 data class CronJob(
     val id: String,
     val name: String,
-    val schedule: Any?,
-    val state: String?,
-    val last_run_status: String?,
-    val next_run: String?,
+    val schedule: JsonElement? = null,
+    val state: String? = null,
+    val last_run_status: String? = null,
+    val next_run: String? = null,
     val schedule_display: String? = null,
     val last_status: String? = null,
     val next_run_at: String? = null,
@@ -36,8 +42,8 @@ data class CronJob(
     val scheduleText: String
         get() =
             when (schedule) {
-                is String -> schedule
-                is Map<*, *> -> (schedule["display"] as? String) ?: schedule_display ?: ""
+                is JsonPrimitive -> schedule.content
+                is JsonObject -> (schedule["display"] as? JsonPrimitive)?.content ?: schedule_display ?: ""
                 else -> schedule_display ?: ""
             }
 

app/src/main/java/com/m57/hermescontrol/data/model/CronJobRequests.kt

@@ -1,5 +1,8 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
 
+@Serializable
 data class CreateCronJobRequest(
     val name: String = "",
     val schedule: String,
@@ -17,6 +20,7 @@ data class CreateCronJobRequest(
     val repeat: Int? = null,
 )
 
+@Serializable
 data class UpdateCronJobRequest(
-    val updates: Map<String, Any?>,
+    val updates: Map<String, JsonElement>,
 )

app/src/main/java/com/m57/hermescontrol/data/model/CuratorResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class CuratorResponse(
     val enabled: Boolean? = null,
     val paused: Boolean? = null,

app/src/main/java/com/m57/hermescontrol/data/model/DebugShareResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class DebugShareResponse(
     val ok: Boolean? = null,
     val urls: Map<String, String>? = null,

app/src/main/java/com/m57/hermescontrol/data/model/DoctorResponse.kt

@@ -1,7 +1,9 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class DoctorResponse(
     val ok: Boolean,
-    val pid: Int?,
-    val name: String?,
+    val pid: Int? = null,
+    val name: String? = null,
 )

app/src/main/java/com/m57/hermescontrol/data/model/EnvVarConfig.kt

@@ -1,32 +1,37 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class EnvVarConfig(
-    @SerializedName("is_set") val isSet: Boolean,
-    @SerializedName("redacted_value") val redactedValue: String?,
-    val description: String?,
-    val url: String?,
-    val category: String?,
-    @SerializedName("is_password") val isPassword: Boolean,
+    @SerialName("is_set") val isSet: Boolean,
+    @SerialName("redacted_value") val redactedValue: String? = null,
+    val description: String? = null,
+    val url: String? = null,
+    val category: String? = null,
+    @SerialName("is_password") val isPassword: Boolean,
 )
 
+@Serializable
 data class EnvVarRevealRequest(
     val key: String,
     val profile: String? = null,
 )
 
+@Serializable
 data class EnvVarRevealResponse(
     val key: String,
     val value: String,
 )
 
+@Serializable
 data class EnvVarUpdate(
     val key: String,
     val value: String,
     val profile: String? = null,
 )
 
+@Serializable
 data class EnvVarDeleteRequest(
     val key: String,
     val profile: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/HookResponse.kt

@@ -1,10 +1,13 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class HookResponse(
     val hooks: List<HookEntry>? = null,
     val valid_events: List<String>? = null,
 )
 
+@Serializable
 data class HookEntry(
     val event: String? = null,
     val matcher: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/Kanban.kt

@@ -1,37 +1,43 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class KanbanBoard(
-    @SerializedName("slug") val id: String,
+    @SerialName("slug") val id: String,
     val name: String,
-    val description: String?,
+    val description: String? = null,
 )
 
+@Serializable
 data class KanbanTask(
     val id: String,
     val title: String,
-    @SerializedName("body") val description: String?,
+    @SerialName("body") val description: String? = null,
     val status: String,
-    @SerializedName("assignee") val assignedTo: String?,
+    @SerialName("assignee") val assignedTo: String? = null,
 )
 
+@Serializable
 data class CreateTaskBody(
     val title: String,
-    val body: String?,
+    val body: String? = null,
 )
 
+@Serializable
 data class KanbanColumn(
     val name: String,
     val tasks: List<KanbanTask>,
 )
 
+@Serializable
 data class KanbanBoardResponse(
     val columns: List<KanbanColumn>,
-    val assignees: List<String>?,
-    val tenants: List<String>?,
+    val assignees: List<String>? = null,
+    val tenants: List<String>? = null,
 )
 
+@Serializable
 data class KanbanBoardsResponse(
     val boards: List<KanbanBoard>,
     val current: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/LogResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class LogResponse(
     val lines: List<String>? = null,
     val logs: List<String>? = null,

app/src/main/java/com/m57/hermescontrol/data/model/McpServer.kt

@@ -1,25 +1,30 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class McpServersResponse(
     val servers: List<McpServer>,
 )
 
+@Serializable
 data class McpServer(
     val name: String,
-    val transport: String?,
-    val url: String?,
-    val command: String?,
-    val args: List<String>?,
-    val env: Map<String, String>?,
+    val transport: String? = null,
+    val url: String? = null,
+    val command: String? = null,
+    val args: List<String>? = null,
+    val env: Map<String, String>? = null,
     val enabled: Boolean,
     val status: String? = null,
     val error: String? = null,
 )
 
+@Serializable
 data class McpServerToggleRequest(
     val enabled: Boolean,
 )
 
+@Serializable
 data class AddMcpServerRequest(
     val name: String,
     val url: String? = null,
@@ -28,10 +33,12 @@ data class AddMcpServerRequest(
     val env: Map<String, String>? = null,
 )
 
+@Serializable
 data class McpCatalogResponse(
     val entries: List<McpCatalogEntry>,
 )
 
+@Serializable
 data class McpCatalogEntry(
     val name: String,
     val description: String? = null,
@@ -42,6 +49,7 @@ data class McpCatalogEntry(
     val env: List<McpCatalogEnvVar>? = null,
 )
 
+@Serializable
 data class McpCatalogEnvVar(
     val key: String,
     val label: String? = null,
@@ -49,6 +57,7 @@ data class McpCatalogEnvVar(
     val required: Boolean = false,
 )
 
+@Serializable
 data class McpCatalogInstallRequest(
     val name: String,
     val env: Map<String, String>? = null,

app/src/main/java/com/m57/hermescontrol/data/model/MemoryResponse.kt

@@ -1,10 +1,13 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class MemoryResponse(
     val active: String? = null,
     val builtin_files: BuiltinFileSizes? = null,
 )
 
+@Serializable
 data class BuiltinFileSizes(
     val memory: Long? = null,
     val user: Long? = null,

app/src/main/java/com/m57/hermescontrol/data/model/MessagingPlatform.kt

@@ -1,57 +1,63 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class MessagingPlatform(
     val id: String,
     val name: String,
     val description: String? = null,
-    @SerializedName("docs_url") val docsUrl: String? = null,
+    @SerialName("docs_url") val docsUrl: String? = null,
     val enabled: Boolean,
     val configured: Boolean,
-    @SerializedName("gateway_running") val gatewayRunning: Boolean = false,
+    @SerialName("gateway_running") val gatewayRunning: Boolean = false,
     val state: String = "disabled",
-    @SerializedName("error_code") val errorCode: String? = null,
-    @SerializedName("error_message") val errorMessage: String? = null,
-    @SerializedName("env_vars") val envVars: List<EnvVarField>? = null,
-    @SerializedName("updated_at") val updatedAt: String? = null,
-    @SerializedName("home_channel") val homeChannel: HomeChannelInfo? = null,
+    @SerialName("error_code") val errorCode: String? = null,
+    @SerialName("error_message") val errorMessage: String? = null,
+    @SerialName("env_vars") val envVars: List<EnvVarField>? = null,
+    @SerialName("updated_at") val updatedAt: String? = null,
+    @SerialName("home_channel") val homeChannel: HomeChannelInfo? = null,
 )
 
+@Serializable
 data class HomeChannelInfo(
     val platform: String,
-    @SerializedName("chat_id") val chatId: String,
+    @SerialName("chat_id") val chatId: String,
     val name: String,
-    @SerializedName("thread_id") val threadId: String? = null,
+    @SerialName("thread_id") val threadId: String? = null,
 )
 
+@Serializable
 data class EnvVarField(
     val key: String,
     val required: Boolean,
-    @SerializedName("is_set") val isSet: Boolean,
-    @SerializedName("redacted_value") val redactedValue: String? = null,
+    @SerialName("is_set") val isSet: Boolean,
+    @SerialName("redacted_value") val redactedValue: String? = null,
     val description: String? = null,
     val prompt: String? = null,
     val help: String? = null,
-    @SerializedName("is_password") val isPassword: Boolean,
+    @SerialName("is_password") val isPassword: Boolean,
     val advanced: Boolean = false,
     val url: String? = null,
-    @SerializedName("expires_at") val expiresAt: String? = null,
+    @SerialName("expires_at") val expiresAt: String? = null,
 )
 
+@Serializable
 data class MessagingPlatformResponse(
-    @SerializedName("env_path") val envPath: String,
-    @SerializedName("gateway_start_command") val gatewayStartCommand: String,
+    @SerialName("env_path") val envPath: String,
+    @SerialName("gateway_start_command") val gatewayStartCommand: String,
     val platforms: List<MessagingPlatform>,
 )
 
+@Serializable
 data class MessagingPlatformUpdate(
     val enabled: Boolean? = null,
     val env: Map<String, String> = emptyMap(),
-    @SerializedName("clear_env") val clearEnv: List<String> = emptyList(),
+    @SerialName("clear_env") val clearEnv: List<String> = emptyList(),
     val profile: String? = null,
 )
 
+@Serializable
 data class MessagingPlatformTestResult(
     val ok: Boolean,
     val state: String,
@@ -60,37 +66,42 @@ data class MessagingPlatformTestResult(
 
 // ── Telegram onboarding ─────────────────────────────────────────────────
 
+@Serializable
 data class TelegramOnboardingStartRequest(
-    @SerializedName("bot_name") val botName: String = "Hermes Agent",
+    @SerialName("bot_name") val botName: String = "Hermes Agent",
 )
 
+@Serializable
 data class TelegramOnboardingStartResponse(
-    @SerializedName("pairing_id") val pairingId: String,
-    @SerializedName("suggested_username") val suggestedUsername: String,
-    @SerializedName("deep_link") val deepLink: String,
-    @SerializedName("qr_payload") val qrPayload: String,
-    @SerializedName("expires_at") val expiresAt: String,
+    @SerialName("pairing_id") val pairingId: String,
+    @SerialName("suggested_username") val suggestedUsername: String,
+    @SerialName("deep_link") val deepLink: String,
+    @SerialName("qr_payload") val qrPayload: String,
+    @SerialName("expires_at") val expiresAt: String,
 )
 
+@Serializable
 data class TelegramOnboardingStatusResponse(
     val status: String,
-    @SerializedName("bot_username") val botUsername: String? = null,
-    @SerializedName("owner_user_id") val ownerUserId: String? = null,
-    @SerializedName("expires_at") val expiresAt: String? = null,
+    @SerialName("bot_username") val botUsername: String? = null,
+    @SerialName("owner_user_id") val ownerUserId: String? = null,
+    @SerialName("expires_at") val expiresAt: String? = null,
 )
 
+@Serializable
 data class TelegramOnboardingApplyRequest(
-    @SerializedName("allowed_user_ids") val allowedUserIds: List<String>,
+    @SerialName("allowed_user_ids") val allowedUserIds: List<String>,
     val profile: String? = null,
 )
 
+@Serializable
 data class TelegramOnboardingApplyResponse(
     val ok: Boolean,
     val platform: String,
-    @SerializedName("bot_username") val botUsername: String? = null,
-    @SerializedName("needs_restart") val needsRestart: Boolean,
-    @SerializedName("restart_started") val restartStarted: Boolean? = null,
-    @SerializedName("restart_action") val restartAction: String? = null,
-    @SerializedName("restart_pid") val restartPid: Int? = null,
-    @SerializedName("restart_error") val restartError: String? = null,
+    @SerialName("bot_username") val botUsername: String? = null,
+    @SerialName("needs_restart") val needsRestart: Boolean,
+    @SerialName("restart_started") val restartStarted: Boolean? = null,
+    @SerialName("restart_action") val restartAction: String? = null,
+    @SerialName("restart_pid") val restartPid: Int? = null,
+    @SerialName("restart_error") val restartError: String? = null,
 )

app/src/main/java/com/m57/hermescontrol/data/model/ModelAssignment.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class AuxiliaryTaskAssignment(
     val task: String,
     val provider: String,
@@ -7,21 +9,25 @@ data class AuxiliaryTaskAssignment(
     val base_url: String? = null,
 )
 
+@Serializable
 data class AuxiliaryModelsResponse(
     val tasks: List<AuxiliaryTaskAssignment>,
     val main: MainModelAssignment,
 )
 
+@Serializable
 data class MainModelAssignment(
     val provider: String,
     val model: String,
 )
 
+@Serializable
 data class MoaModelSlot(
     val provider: String,
     val model: String,
 )
 
+@Serializable
 data class MoaConfigPreset(
     val reference_models: List<MoaModelSlot>,
     val aggregator: MoaModelSlot,
@@ -31,6 +37,7 @@ data class MoaConfigPreset(
     val enabled: Boolean = true,
 )
 
+@Serializable
 data class MoaConfigResponse(
     val default_preset: String = "",
     val active_preset: String = "",
@@ -43,6 +50,7 @@ data class MoaConfigResponse(
     val enabled: Boolean = true,
 )
 
+@Serializable
 data class ModelAssignmentRequest(
     val confirm_expensive_model: Boolean = false,
     val scope: String,
@@ -52,6 +60,7 @@ data class ModelAssignmentRequest(
     val task: String? = null,
 )
 
+@Serializable
 data class ModelAssignmentResponse(
     val confirm_message: String? = null,
     val confirm_required: Boolean? = null,

app/src/main/java/com/m57/hermescontrol/data/model/ModelOption.kt

@@ -1,22 +1,26 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class ModelOptionsResponse(
     val providers: List<ModelProvider>,
 )
 
+@Serializable
 data class ModelProvider(
     val slug: String,
     val name: String,
-    val is_current: Boolean?,
-    val is_user_defined: Boolean?,
-    val models: List<String>?,
-    val total_models: Int?,
-    val source: String?,
-    val authenticated: Boolean?,
-    val auth_type: String?,
-    val warning: String?,
+    val is_current: Boolean? = null,
+    val is_user_defined: Boolean? = null,
+    val models: List<String>? = null,
+    val total_models: Int? = null,
+    val source: String? = null,
+    val authenticated: Boolean? = null,
+    val auth_type: String? = null,
+    val warning: String? = null,
 )
 
+@Serializable
 data class PinnedModel(
     val providerSlug: String,
     val modelName: String,

app/src/main/java/com/m57/hermescontrol/data/model/Pairing.kt

@@ -1,24 +1,29 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class PairingResponse(
     val pending: List<PairingItem>,
     val approved: List<PairingItem>,
 )
 
+@Serializable
 data class PairingItem(
     val platform: String,
-    val user_id: String?,
-    val username: String?,
-    val display_name: String?,
-    val code: String?,
-    val created_at: String?,
+    val user_id: String? = null,
+    val username: String? = null,
+    val display_name: String? = null,
+    val code: String? = null,
+    val created_at: String? = null,
 )
 
+@Serializable
 data class PairingApproveRequest(
     val platform: String,
     val code: String,
 )
 
+@Serializable
 data class PairingRevokeRequest(
     val platform: String,
     val user_id: String,

app/src/main/java/com/m57/hermescontrol/data/model/PluginInfo.kt

@@ -1,20 +1,21 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class PluginInfo(
     val name: String,
-    val description: String?,
-    val version: String?,
-    val source: String?,
-    @SerializedName("runtime_status") val runtimeStatus: String?,
-    @SerializedName("has_dashboard_manifest") val hasDashboardManifest: Boolean = false,
-    @SerializedName("dashboard_manifest") val dashboardManifest: PluginManifestData? = null,
-    @SerializedName("can_remove") val canRemove: Boolean = false,
-    @SerializedName("can_update_git") val canUpdateGit: Boolean = false,
-    @SerializedName("auth_required") val authRequired: Boolean = false,
-    @SerializedName("auth_command") val authCommand: String? = null,
-    @SerializedName("user_hidden") val userHidden: Boolean = false,
+    val description: String? = null,
+    val version: String? = null,
+    val source: String? = null,
+    @SerialName("runtime_status") val runtimeStatus: String? = null,
+    @SerialName("has_dashboard_manifest") val hasDashboardManifest: Boolean = false,
+    @SerialName("dashboard_manifest") val dashboardManifest: PluginManifestData? = null,
+    @SerialName("can_remove") val canRemove: Boolean = false,
+    @SerialName("can_update_git") val canUpdateGit: Boolean = false,
+    @SerialName("auth_required") val authRequired: Boolean = false,
+    @SerialName("auth_command") val authCommand: String? = null,
+    @SerialName("user_hidden") val userHidden: Boolean = false,
 ) {
     val enabled: Boolean
         get() = runtimeStatus.equals("enabled", ignoreCase = true)
@@ -25,6 +26,7 @@ data class PluginInfo(
                 runtimeStatus.equals("disabled", ignoreCase = true)
 }
 
+@Serializable
 data class PluginManifestData(
     val name: String? = null,
     val label: String? = null,
@@ -35,10 +37,11 @@ data class PluginManifestData(
     val slots: List<String>? = null,
     val entry: String? = null,
     val css: String? = null,
-    @SerializedName("has_api") val hasApi: Boolean = false,
+    @SerialName("has_api") val hasApi: Boolean = false,
     val source: String? = null,
 )
 
+@Serializable
 data class PluginTabInfo(
     val path: String? = null,
     val position: String? = null,
@@ -46,6 +49,7 @@ data class PluginTabInfo(
     val hidden: Boolean = false,
 )
 
+@Serializable
 data class DashboardPluginMeta(
     val name: String? = null,
     val label: String? = null,
@@ -53,31 +57,36 @@ data class DashboardPluginMeta(
     val tab: PluginTabInfo? = null,
 )
 
+@Serializable
 data class PluginsHubProviders(
-    @SerializedName("memory_provider") val memoryProvider: String? = null,
-    @SerializedName("memory_options") val memoryOptions: List<ProviderOption> = emptyList(),
-    @SerializedName("context_engine") val contextEngine: String? = null,
-    @SerializedName("context_options") val contextOptions: List<ProviderOption> = emptyList(),
+    @SerialName("memory_provider") val memoryProvider: String? = null,
+    @SerialName("memory_options") val memoryOptions: List<ProviderOption> = emptyList(),
+    @SerialName("context_engine") val contextEngine: String? = null,
+    @SerialName("context_options") val contextOptions: List<ProviderOption> = emptyList(),
 )
 
+@Serializable
 data class ProviderOption(
     val name: String,
     val description: String? = null,
 )
 
+@Serializable
 data class PluginsHubResponse(
     val plugins: List<PluginInfo>,
-    @SerializedName("orphan_dashboard_plugins") val orphanDashboardPlugins: List<DashboardPluginMeta> = emptyList(),
+    @SerialName("orphan_dashboard_plugins") val orphanDashboardPlugins: List<DashboardPluginMeta> = emptyList(),
     val providers: PluginsHubProviders? = null,
 )
 
+@Serializable
 data class AgentPluginInstallBody(
     val identifier: String,
     val force: Boolean = false,
     val enable: Boolean = true,
 )
 
+@Serializable
 data class PluginProvidersPutRequest(
-    @SerializedName("memory_provider") val memoryProvider: String? = null,
-    @SerializedName("context_engine") val contextEngine: String? = null,
+    @SerialName("memory_provider") val memoryProvider: String? = null,
+    @SerialName("context_engine") val contextEngine: String? = null,
 )

app/src/main/java/com/m57/hermescontrol/data/model/PortalResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class PortalResponse(
     val logged_in: Boolean? = null,
     val portal_url: String? = null,
@@ -9,6 +11,7 @@ data class PortalResponse(
     val features: List<PortalFeature>? = null,
 )
 
+@Serializable
 data class PortalFeature(
     val label: String? = null,
     val state: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/Profile.kt

@@ -1,9 +1,12 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class ProfilesResponse(
     val profiles: List<ProfileInfo>,
 )
 
+@Serializable
 data class ProfileInfo(
     val name: String,
     val path: String? = null,
@@ -17,46 +20,55 @@ data class ProfileInfo(
     val description_auto: Boolean? = null,
 )
 
+@Serializable
 data class ActiveProfileResponse(
     val active: String,
-    val current: String?,
+    val current: String? = null,
 )
 
+@Serializable
 data class SetActiveProfileRequest(
     val name: String,
 )
 
+@Serializable
 data class ProfileSoulResponse(
     val content: String,
 )
 
+@Serializable
 data class UpdateProfileSoulRequest(
     val content: String,
 )
 
+@Serializable
 data class UpdateProfileModelRequest(
     val provider: String,
     val model: String,
 )
 
+@Serializable
 data class CloneProfileRequest(
     val name: String,
 )
 
+@Serializable
 data class UpdateProfileDescriptionRequest(
     val description: String,
 )
 
+@Serializable
 data class CreateProfileRequest(
     val name: String,
-    val description: String?,
-    val provider: String?,
-    val model: String?,
-    val mcp_servers: List<McpServerConfigInput>?,
-    val keep_skills: Boolean?,
-    val hub_skills: List<String>?,
+    val description: String? = null,
+    val provider: String? = null,
+    val model: String? = null,
+    val mcp_servers: List<McpServerConfigInput>? = null,
+    val keep_skills: Boolean? = null,
+    val hub_skills: List<String>? = null,
 )
 
+@Serializable
 data class McpServerConfigInput(
     val name: String,
     val transport: String,

app/src/main/java/com/m57/hermescontrol/data/model/SaveSkillContentRequest.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class SaveSkillContentRequest(
     val name: String,
     val content: String,

app/src/main/java/com/m57/hermescontrol/data/model/SessionListResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class SessionListResponse(
     val sessions: List<SessionInfo>,
     val total: Int = 0,
@@ -7,35 +9,41 @@ data class SessionListResponse(
     val offset: Int = 0,
 )
 
+@Serializable
 data class SessionInfo(
     val id: String,
-    val title: String?,
-    val created_at: String?,
-    val message_count: Int?,
-    val status: String?,
+    val title: String? = null,
+    val created_at: String? = null,
+    val message_count: Int? = null,
+    val status: String? = null,
     val preview: String? = null,
     val started_at: Double? = null,
     val source: String? = null,
 )
 
+@Serializable
 data class SessionStatsResponse(
     val total: Int = 0,
     val active: Int = 0,
 )
 
+@Serializable
 data class SessionRenameRequest(
     val title: String,
 )
 
+@Serializable
 data class BulkDeleteRequest(
     val ids: List<String>,
     val delete_all: Boolean = false,
 )
 
+@Serializable
 data class PruneRequest(
     val days: Int,
 )
 
+@Serializable
 data class SessionPromptResponse(
     val prompt: String? = null,
     val id: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/SessionMessagesResponse.kt

@@ -1,12 +1,20 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonPrimitive
 
+@Serializable
 data class SessionMessagesResponse(
     val messages: List<SessionMessage>,
 )
 
+@Serializable
 data class SessionMessage(
-    val role: String?,
-    val content: String?,
-    val timestamp: String?,
-    val type: String?,
-)
+    val role: String? = null,
+    val content: String? = null,
+    val timestamp: JsonElement? = null,
+    val type: String? = null,
+) {
+    val timestampText: String?
+        get() = (timestamp as? JsonPrimitive)?.content
+}

app/src/main/java/com/m57/hermescontrol/data/model/Skill.kt

@@ -1,11 +1,12 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-import com.google.gson.annotations.SerializedName
-
+@Serializable
 data class Skill(
     val name: String,
-    val description: String?,
-    val category: String?,
+    val description: String? = null,
+    val category: String? = null,
     val enabled: Boolean,
     val content: String? = null,
     val source: String? = null, // built-in, hub, optional
@@ -13,40 +14,46 @@ data class Skill(
     val linked_files: List<String>? = null,
 )
 
+@Serializable
 data class HubSkill(
     val name: String,
-    val description: String?,
-    val source: String?,
+    val description: String? = null,
+    val source: String? = null,
     val category: String? = null,
     val identifier: String? = null,
-    @SerializedName("trust_level") val trustLevel: String? = null,
+    @SerialName("trust_level") val trustLevel: String? = null,
     val repo: String? = null,
     val tags: List<String>? = null,
 )
 
+@Serializable
 data class SkillHubSearchResponse(
     val results: List<HubSkill>,
-    @SerializedName("source_counts") val sourceCounts: Map<String, Int>? = null,
-    @SerializedName("timed_out") val timedOut: List<String>? = null,
+    @SerialName("source_counts") val sourceCounts: Map<String, Int>? = null,
+    @SerialName("timed_out") val timedOut: List<String>? = null,
     val installed: Map<String, SkillHubInstalledEntry>? = null,
 )
 
+@Serializable
 data class SkillHubInstalledEntry(
     val name: String? = null,
-    @SerializedName("trust_level") val trustLevel: String? = null,
-    @SerializedName("scan_verdict") val scanVerdict: String? = null,
+    @SerialName("trust_level") val trustLevel: String? = null,
+    @SerialName("scan_verdict") val scanVerdict: String? = null,
 )
 
+@Serializable
 data class SkillHubInstallRequest(
     val identifier: String,
     val profile: String? = null,
 )
 
+@Serializable
 data class SkillHubUninstallRequest(
     val name: String,
     val profile: String? = null,
 )
 
+@Serializable
 data class SkillScanResponse(
     val identifier: String,
     val passed: Boolean? = null,

app/src/main/java/com/m57/hermescontrol/data/model/SkillContentResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class SkillContentResponse(
     val name: String,
     val content: String,

app/src/main/java/com/m57/hermescontrol/data/model/StatusResponse.kt

@@ -1,14 +1,17 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class StatusResponse(
-    val version: String?,
-    val gateway_running: Boolean?,
-    val active_sessions: Int?,
-    val auth_required: Boolean?,
-    val gateway_platforms: Map<String, PlatformStatus>?,
+    val version: String? = null,
+    val gateway_running: Boolean? = null,
+    val active_sessions: Int? = null,
+    val auth_required: Boolean? = null,
+    val gateway_platforms: Map<String, PlatformStatus?>? = null,
 )
 
+@Serializable
 data class PlatformStatus(
-    val state: String?,
+    val state: String? = null,
     val error_code: String? = null,
 )

app/src/main/java/com/m57/hermescontrol/data/model/SystemStatsResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class SystemStatsResponse(
     val os: String? = null,
     val os_release: String? = null,
@@ -20,6 +22,7 @@ data class SystemStatsResponse(
     val process: ProcessStats? = null,
 )
 
+@Serializable
 data class MemoryStats(
     val total: Long? = null,
     val available: Long? = null,
@@ -27,6 +30,7 @@ data class MemoryStats(
     val percent: Double? = null,
 )
 
+@Serializable
 data class DiskStats(
     val total: Long? = null,
     val used: Long? = null,
@@ -34,6 +38,7 @@ data class DiskStats(
     val percent: Double? = null,
 )
 
+@Serializable
 data class ProcessStats(
     val pid: Int? = null,
     val rss: Long? = null,

app/src/main/java/com/m57/hermescontrol/data/model/ToggleSkillRequest.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class ToggleSkillRequest(
     val name: String,
     val enabled: Boolean,

app/src/main/java/com/m57/hermescontrol/data/model/Toolset.kt

@@ -1,15 +1,18 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class Toolset(
     val name: String,
-    val label: String?,
-    val description: String?,
+    val label: String? = null,
+    val description: String? = null,
     val enabled: Boolean,
-    val available: Boolean?,
-    val configured: Boolean?,
-    val tools: List<String>?,
+    val available: Boolean? = null,
+    val configured: Boolean? = null,
+    val tools: List<String>? = null,
 )
 
+@Serializable
 data class ToolsetToggleRequest(
     val enabled: Boolean,
     val profile: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/UpdateCheckResponse.kt

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class UpdateCheckResponse(
     val install_method: String? = null,
     val current_version: String? = null,

app/src/main/java/com/m57/hermescontrol/data/model/Webhook.kt

@@ -1,25 +1,29 @@
 package com.m57.hermescontrol.data.model
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class WebhooksResponse(
     val enabled: Boolean,
-    val base_url: String?,
-    val subscriptions: List<WebhookSubscription>?,
+    val base_url: String? = null,
+    val subscriptions: List<WebhookSubscription>? = null,
 )
 
+@Serializable
 data class WebhookSubscription(
     val name: String,
-    val description: String?,
-    val events: List<String>?,
-    val deliver: String?,
-    val deliver_only: Boolean?,
-    val prompt: String?,
-    val skills: List<String>?,
-    val created_at: String?,
+    val description: String? = null,
+    val events: List<String>? = null,
+    val deliver: String? = null,
+    val deliver_only: Boolean? = null,
+    val prompt: String? = null,
+    val skills: List<String>? = null,
+    val created_at: String? = null,
     val url: String,
-    val secret_set: Boolean?,
-    val enabled: Boolean?,
+    val secret_set: Boolean? = null,
+    val enabled: Boolean? = null,
 )
 
+@Serializable
 data class CreateWebhookRequest(
     val name: String,
     val description: String? = null,
@@ -32,14 +36,17 @@ data class CreateWebhookRequest(
     val secret: String? = null,
 )
 
+@Serializable
 data class WebhooksToggleRequest(
     val enabled: Boolean,
 )
 
+@Serializable
 data class WebhookToggleSubscriptionRequest(
     val enabled: Boolean,
 )
 
+@Serializable
 data class DeleteWebhookResponse(
     val ok: Boolean,
 )