diff --git a/app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt b/app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt
index bbad8a29..b78d4824 100644
--- a/app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt
+++ b/app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt
@@ -80,7 +80,7 @@ object EventParser {
             }
 
             "session.info" -> {
-                WsEvent.SessionInfo(payload)
+                WsEvent.SessionInfo(payload, sessionId)
             }
 
             "message.start" -> {
diff --git a/app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt b/app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt
index 712d4bd5..131693c5 100644
--- a/app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt
+++ b/app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt
@@ -14,6 +14,7 @@ sealed class WsEvent {
 
     data class SessionInfo(
         val data: Map<String, Any?>?,
+        val sessionId: String? = null,
     ) : WsEvent()
 
     // ── Message streaming ────────────────────────────────────────────────
diff --git a/app/src/main/java/com/m57/hermescontrol/data/ws/WsMethods.kt b/app/src/main/java/com/m57/hermescontrol/data/ws/WsMethods.kt
index bb81bd5c..2d585be5 100644
--- a/app/src/main/java/com/m57/hermescontrol/data/ws/WsMethods.kt
+++ b/app/src/main/java/com/m57/hermescontrol/data/ws/WsMethods.kt
@@ -72,6 +72,7 @@ object WsMethods {
     const val COMMANDS_CATALOG = "commands.catalog"
     const val COMMAND_DISPATCH = "command.dispatch"
     const val SLASH_EXEC = "slash.exec"
+    const val CONFIG_GET = "config.get"
     const val CONFIG_SET = "config.set"
 
     // ── Attachments ───────────────────────────────────────────────────────
@@ -166,6 +167,8 @@ object WsMethods {
             // Evidence: methods_session.py @_profile_scoped at each @method
             // Binds HERMES_HOME so config/skills/pets resolve to the
             // focused profile.
+            CONFIG_GET, // methods_config.py: @method("config.get") + @_profile_scoped
+            CONFIG_SET, // methods_config_set.py: @method("config.set") + @_profile_scoped
             "verification.status", // line 282
             PROJECTS_LIST, // methods_projects.py: @_registry.profile_scoped
             "pet.info", // line 1253
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegate.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegate.kt
index 9ccfcda5..1667f98b 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegate.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegate.kt
@@ -10,6 +10,8 @@ import com.m57.hermescontrol.data.remote.NetworkResult
 import com.m57.hermescontrol.data.remote.safeApiCall
 import com.m57.hermescontrol.data.ws.ModelCatalogStore
 import com.m57.hermescontrol.data.ws.WsMethods
+import com.m57.hermescontrol.data.ws.toAny
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
@@ -18,6 +20,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.JsonElement
 import java.util.concurrent.ConcurrentHashMap
 
 /**
@@ -58,6 +61,7 @@ class ChatModelSwitchDelegate(
         { refresh -> ModelCatalogStore.shared.ensureLoaded(forceRefresh = refresh) },
     private val getPinnedModels: () -> List<PinnedModel> = { AuthManager.getPinnedModels() },
     private val savePinnedModels: (List<PinnedModel>) -> Unit = { AuthManager.savePinnedModels(it) },
+    private val wsRequest: (suspend (method: String, params: Map<String, Any>) -> Any?)? = null,
 ) {
     private val pendingModelSwitchRequests = ConcurrentHashMap<String, ActiveModelSwitch>()
     private val pendingFastSwitchRequests = ConcurrentHashMap<String, ActiveFastSwitch>()
@@ -67,6 +71,8 @@ class ChatModelSwitchDelegate(
     private var lastConfirmedModel: String? = null
     private var unconfirmedTargetModel: String? = null
     private var modelSwitchSequence: Long = 0L
+    private var reasoningOpSequence: Long = 0L
+    private var reasoningJob: Job? = null
     private var cachedModelOptions: List<ModelProvider> = emptyList()
     private var cachedModelOptionsScope: DataScope? = dataScopeFlow.value
     private var modelOptionsJob: Job? = null
@@ -460,22 +466,111 @@ class ChatModelSwitchDelegate(
         optimisticPreviousModel = null
         lastConfirmedModel = null
         unconfirmedTargetModel = null
+        reasoningOpSequence++
+        reasoningJob?.cancel()
+        reasoningJob = null
+        uiState.update {
+            it.copy(
+                pendingReasoningLevel = null,
+                reasoningWireLevel = null,
+            )
+        }
     }
 
-    fun setReasoningLevel(level: String?) {
-        uiState.update { it.copy(reasoningLevel = level) }
-        val sessionId = runtimeSessionId() ?: return
+    fun setReasoningLevel(
+        level: String?,
+        scopeName: String = "session",
+        enforceCapabilities: Boolean = true,
+    ) {
         if (level == null) return
-        scope.launch(ioDispatcher) {
-            wsSend(
-                WsMethods.CONFIG_SET,
-                mapOf(
-                    "key" to "reasoning",
-                    "value" to level,
-                    "session_id" to sessionId,
-                ),
-            ) { id -> trackRequest(id, WsMethods.CONFIG_SET) }
+        val currentPending = uiState.value.pendingReasoningLevel
+        if (currentPending != null) return // One reasoning write at a time
+        val sessionId = runtimeSessionId() ?: return
+        if (sessionId.isBlank()) return
+        if (scopeName != "session" && scopeName != "global") return
+
+        // Capability validation
+        if (enforceCapabilities) {
+            val caps = uiState.value.currentModelCapabilities
+            if (caps?.reasoning == false) return
+            if (level == "none" && caps?.can_disable_reasoning == false) return
         }
+
+        val opSeq = ++reasoningOpSequence
+        val capturedScope = dataScopeFlow.value
+        // The old wire value belongs to the previous requested effort. Clear it
+        // before starting the RPC so neither possible ordering can lie:
+        //   ACK first -> wire stays unknown until session.info arrives.
+        //   session.info first -> its fresh wire survives the later ACK.
+        uiState.update {
+            it.copy(
+                pendingReasoningLevel = level,
+                reasoningWireLevel = null,
+            )
+        }
+
+        reasoningJob?.cancel()
+        reasoningJob =
+            scope.launch(ioDispatcher) {
+                try {
+                    val params =
+                        mapOf(
+                            "key" to "reasoning",
+                            "value" to level,
+                            "session_id" to sessionId,
+                            "scope" to scopeName,
+                        )
+                    val result =
+                        if (wsRequest != null) {
+                            wsRequest.invoke(WsMethods.CONFIG_SET, params)
+                        } else {
+                            wsSend(WsMethods.CONFIG_SET, params) { reqId ->
+                                trackRequest(reqId, WsMethods.CONFIG_SET)
+                            }
+                            null
+                        }
+
+                    if (opSeq == reasoningOpSequence && capturedScope == dataScopeFlow.value) {
+                        val ackLevel =
+                            if (wsRequest != null) {
+                                // HermesWsClient.request() completes with the RAW JsonElement.
+                                // Tests and a few injected callers may provide an already-decoded map.
+                                val map =
+                                    when (result) {
+                                        is JsonElement -> result.toAny() as? Map<*, *>
+                                        is Map<*, *> -> result
+                                        else -> null
+                                    }
+                                val resKey = map?.get("key") as? String
+                                val resVal = map?.get("value") as? String
+                                if (resKey != "reasoning" || resVal.isNullOrEmpty()) {
+                                    throw IllegalStateException("Invalid reasoning config.set response")
+                                }
+                                resVal
+                            } else {
+                                level
+                            }
+
+                        uiState.update { state ->
+                            state.copy(
+                                reasoningLevel = ackLevel,
+                                pendingReasoningLevel = null,
+                            )
+                        }
+                    }
+                } catch (e: CancellationException) {
+                    throw e
+                } catch (e: Exception) {
+                    if (opSeq == reasoningOpSequence && capturedScope == dataScopeFlow.value) {
+                        uiState.update { state ->
+                            state.copy(
+                                pendingReasoningLevel = null,
+                                errorMessage = "Could not confirm reasoning change: ${e.message ?: e.toString()}",
+                            )
+                        }
+                    }
+                }
+            }
     }
 
     fun getModelCapabilities(
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt
index 287ce2fb..8c935e40 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt
@@ -808,6 +808,8 @@ fun ChatScreen(
                 currentSessionModel = state.currentSessionModel,
                 showModelProvider = state.showModelProvider,
                 reasoningLevel = state.reasoningLevel,
+                reasoningWireLevel = state.reasoningWireLevel,
+                pendingReasoningLevel = state.pendingReasoningLevel,
                 onModelTap = { viewModel.openModelPicker() },
                 onReasoningTap = { level -> viewModel.setReasoningLevel(level) },
                 canDisableReasoning = state.currentModelCapabilities?.can_disable_reasoning,
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt
index cf5ec8c8..1154a550 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt
@@ -27,6 +27,7 @@ import com.m57.hermescontrol.data.ws.ConnectionStatus
 import com.m57.hermescontrol.data.ws.HermesWsClient
 import com.m57.hermescontrol.data.ws.WsEvent
 import com.m57.hermescontrol.data.ws.WsMethods
+import com.m57.hermescontrol.data.ws.toAny
 import com.m57.hermescontrol.data.ws.toJsonElement
 import com.m57.hermescontrol.notification.captureTurnBoundary
 import com.m57.hermescontrol.notification.correlationScopeId
@@ -45,6 +46,7 @@ import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.JsonElement
 import kotlinx.serialization.json.JsonObject
 import kotlinx.serialization.json.buildJsonObject
 import kotlinx.serialization.json.decodeFromJsonElement
@@ -56,6 +58,42 @@ import java.util.concurrent.ConcurrentHashMap
 private const val TAG = "ChatViewModel"
 private const val MESSAGE_PAGE_SIZE = 150
 
+private val REASONING_EFFORT_LEVELS =
+    setOf("none", "minimal", "low", "medium", "high", "xhigh", "max", "ultra")
+
+private data class ReasoningSlashArgs(
+    val value: String,
+    val scopeName: String?,
+)
+
+/** Mirrors Desktop's reasoningSlashParams(): flags may appear in any order. */
+private fun parseReasoningSlashArgs(arg: String): ReasoningSlashArgs? {
+    var scopeName: String? = null
+    val values = mutableListOf<String>()
+
+    arg
+        .trim()
+        .split(Regex("\\s+"))
+        .filter { it.isNotBlank() }
+        .forEach { part ->
+            when (part.lowercase()) {
+                "--global", "-g", "global" -> scopeName = "global"
+                "--session", "-s", "session" -> scopeName = "session"
+                else -> values += part
+            }
+        }
+
+    if (values.isEmpty()) return null
+    return ReasoningSlashArgs(values.joinToString(" "), scopeName)
+}
+
+private fun rpcResultMap(result: Any?): Map<*, *>? =
+    when (result) {
+        is JsonElement -> result.toAny() as? Map<*, *>
+        is Map<*, *> -> result
+        else -> null
+    }
+
 private data class PreparedAttachment(
     val attachment: Attachment,
     val encodedFile: File,
@@ -145,6 +183,10 @@ data class ChatUiState(
     val currentModelCapabilities: ModelCapabilities? = null,
     // Reasoning effort level for the current session
     val reasoningLevel: String? = null,
+    // Gateway-reported effective effort on the active route (clamped level, e.g. "max" when requested was "ultra")
+    val reasoningWireLevel: String? = null,
+    // In-flight reasoning effort currently applying via config.set
+    val pendingReasoningLevel: String? = null,
     // Fast mode / Priority processing state for the current session
     val fastMode: Boolean = false,
     val isFastModeChanging: Boolean = false,
@@ -479,6 +521,7 @@ class ChatViewModel(
             handleSlashCommand = { cmd -> handleSlashCommand(cmd) },
             fetchContextUsage = { fetchContextUsage() },
             onModelSwitchInitiated = { onModelSwitchInitiated() },
+            wsRequest = { method, params -> wsClient.request(method, params).await() },
         ).apply {
             attachScopeObserver(viewModelScope)
         }
@@ -788,7 +831,11 @@ class ChatViewModel(
             }
 
             is WsEvent.SessionInfo -> {
-                handleSessionInfo(event.data)
+                val current = runtimeSessionId ?: _uiState.value.currentSessionId
+                // Ignore session.info events clearly tagged for a different session
+                if (event.sessionId == null || current == null || event.sessionId == current) {
+                    handleSessionInfo(event.data)
+                }
             }
 
             is WsEvent.MessageToken -> {
@@ -1178,6 +1225,7 @@ class ChatViewModel(
             val model = info["model"] as? String
             val provider = info["provider"] as? String
             val reasoningEffort = info["reasoning_effort"] as? String
+            val reasoningEffortWire = info["reasoning_effort_wire"] as? String
             val terminalBackend = info["terminal_backend"] as? String
             val serviceTier = (info["service_tier"] as? String)?.trim()?.lowercase()
             val fastFlag =
@@ -1209,14 +1257,24 @@ class ChatViewModel(
                 modelSwitchDelegate.onModelConfirmed(newModelLabel)
             }
             _uiState.update { state ->
+                val newEffort =
+                    if (reasoningEffort != null) {
+                        if (reasoningEffort.isEmpty()) null else reasoningEffort
+                    } else {
+                        state.reasoningLevel
+                    }
+                val newWire =
+                    if (reasoningEffortWire != null) {
+                        if (reasoningEffortWire.isEmpty()) null else reasoningEffortWire
+                    } else if (newEffort != state.reasoningLevel || modelSwapped) {
+                        null
+                    } else {
+                        state.reasoningWireLevel
+                    }
                 state.copy(
                     currentSessionModel = newModelLabel ?: state.currentSessionModel,
-                    reasoningLevel =
-                        if (reasoningEffort.isNullOrEmpty()) {
-                            null
-                        } else {
-                            reasoningEffort
-                        },
+                    reasoningLevel = newEffort,
+                    reasoningWireLevel = newWire,
                     fastMode = fastFlag ?: state.fastMode,
                     isFastModeChanging = if (fastFlag != null) false else state.isFastModeChanging,
                     terminalBackend = terminalBackend ?: state.terminalBackend,
@@ -1388,6 +1446,7 @@ class ChatViewModel(
                 val model = infoMap?.get("model") as? String
                 val provider = infoMap?.get("provider") as? String
                 val reasoningEffort = infoMap?.get("reasoning_effort") as? String
+                val reasoningEffortWire = infoMap?.get("reasoning_effort_wire") as? String
                 val terminalBackend = infoMap?.get("terminal_backend") as? String
                 val serviceTier = (infoMap?.get("service_tier") as? String)?.trim()?.lowercase()
                 val fastFlag =
@@ -1416,6 +1475,12 @@ class ChatViewModel(
                             } else {
                                 reasoningEffort
                             },
+                        reasoningWireLevel =
+                            if (reasoningEffortWire.isNullOrEmpty()) {
+                                null
+                            } else {
+                                reasoningEffortWire
+                            },
                         fastMode = fastFlag ?: false,
                         isFastModeChanging = false,
                         terminalBackend = terminalBackend ?: it.terminalBackend,
@@ -1705,7 +1770,8 @@ class ChatViewModel(
     }
 
     private fun canSubmitMessage(): Boolean =
-        wsClient.connectionStatus.value == ConnectionStatus.CONNECTED &&
+        _uiState.value.pendingReasoningLevel == null &&
+            wsClient.connectionStatus.value == ConnectionStatus.CONNECTED &&
             (
                 (_uiState.value.isSessionReady && runtimeSessionId != null) ||
                     (
@@ -2127,6 +2193,10 @@ class ChatViewModel(
                 modelSwitchDelegate.handleModelSwitch(command)
             }
 
+            is SlashResult.ReasoningSwitch -> {
+                handleReasoningSlashCommand(result.level)
+            }
+
             is SlashResult.Update -> {
                 openUpdateConfirm()
             }
@@ -2174,6 +2244,97 @@ class ChatViewModel(
         submitPrompt(arg, queued = true)
     }
 
+    private fun handleReasoningSlashCommand(arg: String) {
+        val sessionId = runtimeSessionId
+        if (sessionId.isNullOrBlank()) {
+            addAssistantMessage("Reasoning controls require an active session.")
+            return
+        }
+
+        val parsed = parseReasoningSlashArgs(arg)
+
+        // Bare `/reasoning` is a status query, matching Desktop/TUI semantics.
+        if (parsed == null) {
+            viewModelScope.launch(ioDispatcher) {
+                try {
+                    val result =
+                        wsClient
+                            .request(
+                                WsMethods.CONFIG_GET,
+                                mapOf(
+                                    "key" to "reasoning",
+                                    "session_id" to sessionId,
+                                ),
+                            ).await()
+                    val map = rpcResultMap(result) ?: error("Invalid reasoning config.get response")
+                    val value = (map["value"] as? String)?.takeIf { it.isNotBlank() } ?: "unknown"
+                    val display = (map["display"] as? String)?.takeIf { it.isNotBlank() } ?: "unknown"
+                    addAssistantMessage("reasoning: $value · display $display")
+                } catch (e: CancellationException) {
+                    throw e
+                } catch (e: Exception) {
+                    addAssistantMessage("Could not read reasoning status: ${e.message ?: e.toString()}")
+                }
+            }
+            return
+        }
+
+        val value = parsed.value.trim().lowercase()
+
+        // Effort changes use the acknowledged delegate so the composer shows
+        // pending state and prompt submission remains gated until config.set
+        // succeeds. A global preference may target a future model, so do not
+        // reject it based on only the current model's capabilities.
+        if (value in REASONING_EFFORT_LEVELS) {
+            if (parsed.scopeName != "global") {
+                val caps = _uiState.value.currentModelCapabilities
+                if (caps?.reasoning == false) {
+                    addAssistantMessage("Reasoning is not supported for the current model.")
+                    return
+                }
+                if (value == "none" && caps?.can_disable_reasoning == false) {
+                    addAssistantMessage("Reasoning cannot be disabled for this model (always on).")
+                    return
+                }
+            }
+            modelSwitchDelegate.setReasoningLevel(
+                value,
+                scopeName = parsed.scopeName ?: "session",
+                enforceCapabilities = parsed.scopeName != "global",
+            )
+            return
+        }
+
+        // Display controls (`show`/`hide`/`full`/`clamp` and backend aliases)
+        // and future config.set reasoning values go through the canonical
+        // backend parser instead of a client-maintained allowlist. Invalid
+        // values therefore surface the real 4002 error instead of being eaten
+        // locally. Scope flags are forwarded exactly like Desktop.
+        viewModelScope.launch(ioDispatcher) {
+            try {
+                val params =
+                    buildMap<String, Any> {
+                        put("key", "reasoning")
+                        put("value", parsed.value)
+                        put("session_id", sessionId)
+                        parsed.scopeName?.let { put("scope", it) }
+                    }
+                val result = wsClient.request(WsMethods.CONFIG_SET, params).await()
+                val map = rpcResultMap(result) ?: error("Invalid reasoning config.set response")
+                val responseKey = map["key"] as? String
+                val responseValue = map["value"] as? String
+                if (responseKey != "reasoning" || responseValue.isNullOrBlank()) {
+                    error("Invalid reasoning config.set response")
+                }
+                addAssistantMessage("reasoning: $responseValue")
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: Exception) {
+                addAssistantMessage("Could not change reasoning: ${e.message ?: e.toString()}")
+            }
+        }
+    }
+
     // ── Side Questions via /btw (issue #1015) ─────────────────────────────
 
     fun dismissBtw() {
@@ -2962,6 +3123,8 @@ class ChatViewModel(
                 currentSessionModel = null,
                 currentModelCapabilities = null,
                 reasoningLevel = null,
+                reasoningWireLevel = null,
+                pendingReasoningLevel = null,
                 fastMode = false,
                 isFastModeChanging = false,
                 terminalBackend = null,
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcher.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcher.kt
index f96d78a7..31712655 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcher.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcher.kt
@@ -42,6 +42,11 @@ class SlashCommandDispatcher {
                 SlashResult.ModelSwitch
             }
 
+            "/reasoning" -> {
+                val arg = command.split(" ", limit = 2).getOrElse(1) { "" }.trim()
+                SlashResult.ReasoningSwitch(level = arg)
+            }
+
             "/update" -> {
                 SlashResult.Update
             }
@@ -103,6 +108,16 @@ sealed class SlashResult {
      */
     data object ModelSwitch : SlashResult()
 
+    /**
+     * Handle `/reasoning` through the gateway's first-class config RPCs rather
+     * than command.dispatch (which 4018s on it). [level] intentionally carries
+     * the raw argument tail: it may be an effort, a display word
+     * (`show`/`hide`/`full`/`clamp`), or include `--global` / `--session`.
+     */
+    data class ReasoningSwitch(
+        val level: String,
+    ) : SlashResult()
+
     /**
      * Trigger the backend update via the REST action API
      * (`POST /api/hermes/update`, the System screen's flow) and track it in
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ChatComposer.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ChatComposer.kt
index 67efc277..cf67124f 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ChatComposer.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ChatComposer.kt
@@ -101,12 +101,16 @@ fun ChatInputBar(
     isFastModeChanging: Boolean = false,
     onToggleFastMode: () -> Unit = {},
     showModelProvider: Boolean = false,
+    reasoningWireLevel: String? = null,
+    pendingReasoningLevel: String? = null,
 ) {
     // Allow sending while the agent is mid-turn or awaiting approval: the
     // gateway's prompt.submit busy-input policy queues it as the next turn
     // (tui_gateway/server.py:_handle_busy_submit), so the message is never
     // dropped. Slash commands were already allowed; regular prompts now are too.
-    val canSend = ChatInputPolicy.canSend(inputFieldValue.text, pendingAttachments, isConnected, isSessionReady)
+    val canSend =
+        pendingReasoningLevel == null &&
+            ChatInputPolicy.canSend(inputFieldValue.text, pendingAttachments, isConnected, isSessionReady)
 
     // Attachment tray state
     var showAttachmentTray by remember { mutableStateOf(false) }
@@ -329,6 +333,9 @@ fun ChatInputBar(
                     isFastModeChanging = isFastModeChanging,
                     onToggleFastMode = onToggleFastMode,
                     showModelProvider = showModelProvider,
+                    reasoningWireLevel = reasoningWireLevel,
+                    pendingReasoningLevel = pendingReasoningLevel,
+                    isSessionReady = isSessionReady,
                 )
 
                 AttachmentTray(
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ComposerToolbar.kt b/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ComposerToolbar.kt
index ac1de39d..bfee7e24 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ComposerToolbar.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/chat/components/ComposerToolbar.kt
@@ -104,6 +104,9 @@ fun ComposerToolbar(
     isFastModeChanging: Boolean = false,
     onToggleFastMode: () -> Unit = {},
     showModelProvider: Boolean = false,
+    reasoningWireLevel: String? = null,
+    pendingReasoningLevel: String? = null,
+    isSessionReady: Boolean = true,
 ) {
     var showReasoningMenu by remember { mutableStateOf(false) }
     val palette = composerPalette()
@@ -179,11 +182,12 @@ fun ComposerToolbar(
                 }
 
                 Box {
+                    val reasoningInteractive = isConnected && isSessionReady && pendingReasoningLevel == null
                     Row(
                         modifier =
                             Modifier
                                 .fillMaxHeight()
-                                .clickable(enabled = isConnected) { showReasoningMenu = true }
+                                .clickable(enabled = reasoningInteractive) { showReasoningMenu = true }
                                 .padding(start = 6.dp, end = 12.dp)
                                 .testTag("reasoning_chip"),
                         verticalAlignment = Alignment.CenterVertically,
@@ -191,7 +195,7 @@ fun ComposerToolbar(
                     ) {
                         val levelColor =
                             palette.onControlVariant.copy(
-                                alpha = if (isConnected) 1f else 0.38f,
+                                alpha = if (reasoningInteractive) 1f else 0.38f,
                             )
                         if (fastMode) {
                             Icon(
@@ -201,12 +205,26 @@ fun ComposerToolbar(
                                 modifier = Modifier.size(14.dp),
                             )
                         }
+                        if (pendingReasoningLevel != null) {
+                            CircularProgressIndicator(
+                                modifier = Modifier.size(12.dp),
+                                strokeWidth = 1.5.dp,
+                                color = MaterialTheme.colorScheme.primary,
+                            )
+                        }
                         Text(
                             text =
                                 if (reasoningDisabledForModel) {
                                     if (fastMode) stringResource(R.string.chat_fast_mode_label) else "No reasoning"
                                 } else {
-                                    val rLabel = buildReasoningLabel(reasoningLevel)
+                                    val targetEffort = pendingReasoningLevel ?: reasoningLevel
+                                    val wire = if (pendingReasoningLevel != null) null else reasoningWireLevel
+                                    val rLabel =
+                                        buildReasoningLabel(
+                                            level = targetEffort,
+                                            wireLevel = wire,
+                                            defaultLabel = stringResource(R.string.chat_reasoning_default),
+                                        )
                                     if (fastMode) {
                                         "${stringResource(
                                             R.string.chat_fast_mode_label,
@@ -332,29 +350,57 @@ fun ComposerToolbar(
                         allLevels.forEach { (level, label) ->
                             val isNone = level == "none"
                             val noneDisabled = isNone && (canDisable == false || reasoningDisabledForModel)
+                            val isSelected = (pendingReasoningLevel ?: reasoningLevel) == level
+                            val isClampedTarget =
+                                isSelected && reasoningWireLevel != null &&
+                                    !reasoningWireLevel.equals(level, ignoreCase = true)
                             DropdownMenuItem(
                                 text = {
-                                    Text(
-                                        text = label,
-                                        fontWeight =
-                                            if (reasoningLevel == level) {
-                                                MaterialTheme.typography.bodyMedium.fontWeight
-                                            } else {
-                                                null
-                                            },
-                                        color =
-                                            when {
-                                                noneDisabled -> MaterialTheme.colorScheme.onSurface.copy(alpha = 0.38f)
-                                                reasoningLevel == level -> MaterialTheme.colorScheme.primary
-                                                else -> MaterialTheme.colorScheme.onSurface
-                                            },
-                                    )
+                                    Column {
+                                        Text(
+                                            text = label,
+                                            fontWeight =
+                                                if (isSelected) {
+                                                    MaterialTheme.typography.bodyMedium.fontWeight
+                                                } else {
+                                                    null
+                                                },
+                                            color =
+                                                when {
+                                                    noneDisabled -> {
+                                                        MaterialTheme.colorScheme.onSurface.copy(
+                                                            alpha = 0.38f,
+                                                        )
+                                                    }
+
+                                                    isSelected -> {
+                                                        MaterialTheme.colorScheme.primary
+                                                    }
+
+                                                    else -> {
+                                                        MaterialTheme.colorScheme.onSurface
+                                                    }
+                                                },
+                                        )
+                                        if (isClampedTarget) {
+                                            Text(
+                                                text =
+                                                    stringResource(
+                                                        R.string.chat_reasoning_clamped_desc,
+                                                        label,
+                                                        buildReasoningLabel(reasoningWireLevel, defaultLabel = ""),
+                                                    ),
+                                                style = MaterialTheme.typography.labelSmall,
+                                                color = MaterialTheme.colorScheme.primary.copy(alpha = 0.8f),
+                                            )
+                                        }
+                                    }
                                 },
                                 onClick = {
                                     showReasoningMenu = false
                                     onReasoningSelected(level)
                                 },
-                                enabled = !noneDisabled && !reasoningDisabledForModel,
+                                enabled = !noneDisabled && !reasoningDisabledForModel && pendingReasoningLevel == null,
                             )
                         }
                     }
@@ -501,16 +547,37 @@ private const val CUSTOM_PROVIDER_PREFIX = "custom:"
  *              "xhigh", "max", "ultra", or null for model default.
  * @return Display string such as "None", "Low", "XHigh", "Ultra", etc.
  */
-private fun buildReasoningLabel(level: String?): String =
-    when (level) {
-        null -> "Med"
-        "none" -> "None"
-        "minimal" -> "Minimal"
-        "low" -> "Low"
-        "medium" -> "Med"
-        "high" -> "High"
-        "xhigh" -> "XHigh"
-        "max" -> "Max"
-        "ultra" -> "Ultra"
-        else -> level
+fun buildReasoningLabel(
+    level: String?,
+    wireLevel: String? = null,
+    defaultLabel: String = "Default",
+): String {
+    val reqLabel =
+        when (level) {
+            null -> defaultLabel
+            "none" -> "None"
+            "minimal" -> "Minimal"
+            "low" -> "Low"
+            "medium" -> "Med"
+            "high" -> "High"
+            "xhigh" -> "XHigh"
+            "max" -> "Max"
+            "ultra" -> "Ultra"
+            else -> level
+        }
+    if (wireLevel != null && !wireLevel.equals(level, ignoreCase = true) && level != "none") {
+        val wireLabel =
+            when (wireLevel) {
+                "minimal" -> "Minimal"
+                "low" -> "Low"
+                "medium" -> "Med"
+                "high" -> "High"
+                "xhigh" -> "XHigh"
+                "max" -> "Max"
+                "ultra" -> "Ultra"
+                else -> wireLevel
+            }
+        return "$reqLabel→$wireLabel"
     }
+    return reqLabel
+}
diff --git a/app/src/main/res/values-ar/strings.xml b/app/src/main/res/values-ar/strings.xml
index 83265e23..80f5cb59 100644
--- a/app/src/main/res/values-ar/strings.xml
+++ b/app/src/main/res/values-ar/strings.xml
@@ -1294,6 +1294,9 @@
 <string name="chat_fast_mode_label">سريع</string>
 <string name="chat_fast_mode_desc">الوضع السريع</string>
 <string name="chat_fast_mode_unavailable">الوضع السريع غير مدعوم لهذا النموذج</string>
+<string name="chat_reasoning_default">الافتراضي</string>
+<string name="chat_reasoning_applying">جارٍ تطبيق الاستدلال…</string>
+<string name="chat_reasoning_clamped_desc">المطلوب %1$s، يرسل المسار %2$s</string>
 <string name="chat_save_attachment">حفظ %1$s</string>
 <string name="chat_switch_model_title">تبديل النموذج (لهذه المحادثة)</string>
 <string name="config_clear_value">مسح القيمة</string>
diff --git a/app/src/main/res/values-ko/strings.xml b/app/src/main/res/values-ko/strings.xml
index 8d9afa91..ee1048c0 100644
--- a/app/src/main/res/values-ko/strings.xml
+++ b/app/src/main/res/values-ko/strings.xml
@@ -1140,6 +1140,9 @@
     <string name="chat_fast_mode_label">빠름</string>
     <string name="chat_fast_mode_desc">빠른 모드</string>
     <string name="chat_fast_mode_unavailable">이 모델에서는 빠른 모드를 사용할 수 없습니다</string>
+    <string name="chat_reasoning_default">기본값</string>
+    <string name="chat_reasoning_applying">추론 설정 적용 중…</string>
+    <string name="chat_reasoning_clamped_desc">요청 %1$s, 경로 전송 %2$s</string>
 
     <!-- Session Integrations (issue #1091) -->
     <string name="session_integrations_title">연동</string>
diff --git a/app/src/main/res/values-zh/strings.xml b/app/src/main/res/values-zh/strings.xml
index 0c36aea0..5cbae308 100644
--- a/app/src/main/res/values-zh/strings.xml
+++ b/app/src/main/res/values-zh/strings.xml
@@ -1261,6 +1261,9 @@
     <string name="chat_fast_mode_label">快速</string>
     <string name="chat_fast_mode_desc">快速模式</string>
     <string name="chat_fast_mode_unavailable">此模型不支持快速模式</string>
+    <string name="chat_reasoning_default">默认</string>
+    <string name="chat_reasoning_applying">正在应用推理设置…</string>
+    <string name="chat_reasoning_clamped_desc">请求 %1$s，路由实际发送 %2$s</string>
     <string name="chat_save_attachment">保存 %1$s</string>
     <string name="chat_switch_model_title">切换模型（当前对话）</string>
     <string name="config_clear_value">清除值</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index c5f01c34..9d6e2222 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1420,6 +1420,9 @@
     <string name="chat_fast_mode_label">Fast</string>
     <string name="chat_fast_mode_desc">Fast mode</string>
     <string name="chat_fast_mode_unavailable">Fast mode unavailable for this model</string>
+    <string name="chat_reasoning_default">Default</string>
+    <string name="chat_reasoning_applying">Applying reasoning…</string>
+    <string name="chat_reasoning_clamped_desc">Requested %1$s, route sends %2$s</string>
     <string name="chat_reasoning_menu_desc">Reasoning options</string>
     <string name="chat_save_attachment">Save %1$s</string>
     <string name="chat_switch_model_title">Switch model (this chat)</string>
diff --git a/app/src/test/java/com/m57/hermescontrol/data/ws/EventParserTest.kt b/app/src/test/java/com/m57/hermescontrol/data/ws/EventParserTest.kt
index 70a8f0cf..892b9d69 100644
--- a/app/src/test/java/com/m57/hermescontrol/data/ws/EventParserTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/data/ws/EventParserTest.kt
@@ -715,11 +715,17 @@ class EventParserTest {
                 result = null,
                 error = null,
                 method = "event",
-                params = mapOf("type" to "session.info", "payload" to mapOf("session_id" to "sess-1")),
+                params =
+                    mapOf(
+                        "type" to "session.info",
+                        "session_id" to "sess-1",
+                        "payload" to mapOf("session_id" to "sess-1"),
+                    ),
             )
         val event = EventParser.parse(response)
         assertTrue(event is WsEvent.SessionInfo)
         assertEquals(mapOf("session_id" to "sess-1"), (event as WsEvent.SessionInfo).data)
+        assertEquals("sess-1", event.sessionId)
     }
 
     @Test
diff --git a/app/src/test/java/com/m57/hermescontrol/data/ws/WsProfileParamsTest.kt b/app/src/test/java/com/m57/hermescontrol/data/ws/WsProfileParamsTest.kt
index a0825212..a1f7cd81 100644
--- a/app/src/test/java/com/m57/hermescontrol/data/ws/WsProfileParamsTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/data/ws/WsProfileParamsTest.kt
@@ -88,6 +88,21 @@ class WsProfileParamsTest {
         assertEquals("meow", result["profile"])
     }
 
+    @Test
+    fun `config get and set are profile scoped`() {
+        AuthManager.setActiveProfileId("work")
+
+        val getResult = WsProfileParams.decorate(WsMethods.CONFIG_GET, mapOf("key" to "reasoning"))
+        val setResult =
+            WsProfileParams.decorate(
+                WsMethods.CONFIG_SET,
+                mapOf("key" to "reasoning", "value" to "high"),
+            )
+
+        assertEquals("work", getResult["profile"])
+        assertEquals("work", setResult["profile"])
+    }
+
     @Test
     fun `profile_scoped decorator method gets profile injected`() {
         AuthManager.setActiveProfileId("meow")
diff --git a/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegateTest.kt b/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegateTest.kt
index efe0c636..f8ee5ecb 100644
--- a/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegateTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatModelSwitchDelegateTest.kt
@@ -430,6 +430,163 @@ class ChatModelSwitchDelegateTest {
             assertEquals("anthropic/claude-3-5-sonnet", uiState.value.currentSessionModel)
         }
 
+    @Test
+    fun setReasoningLevel_awaitsRequest_updatesOnAck_andPreventsConcurrentPick() =
+        testScope.runTest {
+            val gate = CompletableDeferred<Any?>()
+            val reqMethods = mutableListOf<String>()
+            val reqParams = mutableListOf<Map<String, Any>>()
+
+            val customDelegate =
+                ChatModelSwitchDelegate(
+                    scope = testScope,
+                    ioDispatcher = testDispatcher,
+                    uiState = uiState,
+                    runtimeSessionId = { runtimeId },
+                    wsSend = { _, _, _ -> },
+                    trackRequest = { _, _ -> },
+                    addAssistantMessage = {},
+                    handleSlashCommand = {},
+                    fetchContextUsage = {},
+                    dataScopeFlow = dataScope,
+                    wsRequest = { method, params ->
+                        reqMethods.add(method)
+                        reqParams.add(params)
+                        gate.await()
+                    },
+                )
+
+            uiState.value = uiState.value.copy(reasoningLevel = "ultra", reasoningWireLevel = "max")
+
+            customDelegate.setReasoningLevel("high")
+            runCurrent()
+
+            // Confirmed level remains unchanged until acknowledged. The stale
+            // wire is cleared immediately so "High→Max" can never be painted.
+            assertEquals("ultra", uiState.value.reasoningLevel)
+            assertEquals("high", uiState.value.pendingReasoningLevel)
+            assertNull(uiState.value.reasoningWireLevel)
+            assertEquals(listOf(WsMethods.CONFIG_SET), reqMethods)
+            assertEquals("session", reqParams.first()["scope"])
+            assertEquals("high", reqParams.first()["value"])
+
+            // Second pick while in-flight is rejected (serialized)
+            customDelegate.setReasoningLevel("low")
+            runCurrent()
+            assertEquals(1, reqMethods.size)
+
+            // Simulate session.info winning the race and publishing the fresh
+            // authoritative wire before the RPC ACK resumes the delegate.
+            uiState.value = uiState.value.copy(reasoningWireLevel = "high")
+
+            // Production request() returns a raw JsonObject, not a Map.
+            gate.complete(
+                kotlinx.serialization.json.buildJsonObject {
+                    put("key", kotlinx.serialization.json.JsonPrimitive("reasoning"))
+                    put("value", kotlinx.serialization.json.JsonPrimitive("high"))
+                },
+            )
+            advanceUntilIdle()
+
+            assertEquals("high", uiState.value.reasoningLevel)
+            assertNull(uiState.value.pendingReasoningLevel)
+            // ACK must not erase a fresh wire that arrived first.
+            assertEquals("high", uiState.value.reasoningWireLevel)
+        }
+
+    @Test
+    fun setReasoningLevel_onFailure_clearsPendingAndSurfacesError() =
+        testScope.runTest {
+            val customDelegate =
+                ChatModelSwitchDelegate(
+                    scope = testScope,
+                    ioDispatcher = testDispatcher,
+                    uiState = uiState,
+                    runtimeSessionId = { runtimeId },
+                    wsSend = { _, _, _ -> },
+                    trackRequest = { _, _ -> },
+                    addAssistantMessage = {},
+                    handleSlashCommand = {},
+                    fetchContextUsage = {},
+                    dataScopeFlow = dataScope,
+                    wsRequest = { _, _ -> throw RuntimeException("4002 unknown reasoning value") },
+                )
+
+            customDelegate.setReasoningLevel("ultra")
+            advanceUntilIdle()
+
+            assertNull(uiState.value.reasoningLevel)
+            assertNull(uiState.value.pendingReasoningLevel)
+            assertTrue(uiState.value.errorMessage?.contains("4002") == true)
+        }
+
+    @Test
+    fun setReasoningLevel_whenRuntimeSessionNullOrBlank_doesNotSend() =
+        testScope.runTest {
+            val reqMethods = mutableListOf<String>()
+            runtimeId = null
+
+            val customDelegate =
+                ChatModelSwitchDelegate(
+                    scope = testScope,
+                    ioDispatcher = testDispatcher,
+                    uiState = uiState,
+                    runtimeSessionId = { runtimeId },
+                    wsSend = { _, _, _ -> },
+                    trackRequest = { _, _ -> },
+                    addAssistantMessage = {},
+                    handleSlashCommand = {},
+                    fetchContextUsage = {},
+                    dataScopeFlow = dataScope,
+                    wsRequest = { method, _ ->
+                        reqMethods.add(method)
+                        null
+                    },
+                )
+
+            customDelegate.setReasoningLevel("high")
+            advanceUntilIdle()
+
+            assertTrue(reqMethods.isEmpty())
+            assertNull(uiState.value.pendingReasoningLevel)
+            assertNull(uiState.value.reasoningLevel)
+        }
+
+    @Test
+    fun setReasoningLevel_staleScopeOrReset_dropsLateAck() =
+        testScope.runTest {
+            val gate = CompletableDeferred<Any?>()
+            val customDelegate =
+                ChatModelSwitchDelegate(
+                    scope = testScope,
+                    ioDispatcher = testDispatcher,
+                    uiState = uiState,
+                    runtimeSessionId = { runtimeId },
+                    wsSend = { _, _, _ -> },
+                    trackRequest = { _, _ -> },
+                    addAssistantMessage = {},
+                    handleSlashCommand = {},
+                    fetchContextUsage = {},
+                    dataScopeFlow = dataScope,
+                    wsRequest = { _, _ -> gate.await() },
+                )
+
+            customDelegate.setReasoningLevel("high")
+            runCurrent()
+            assertEquals("high", uiState.value.pendingReasoningLevel)
+
+            // Reset called while in-flight
+            customDelegate.reset()
+            assertNull(uiState.value.pendingReasoningLevel)
+
+            // Late RPC response arrives
+            gate.complete(mapOf("key" to "reasoning", "value" to "high"))
+            advanceUntilIdle()
+
+            assertNull(uiState.value.reasoningLevel)
+            assertNull(uiState.value.pendingReasoningLevel)
+        }
+
     @Test
     fun rapidPicks_preservesOriginalConfirmedModelForRollback() =
         testScope.runTest {
diff --git a/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt b/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt
index 7c072688..68a69b9c 100644
--- a/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt
@@ -2651,9 +2651,50 @@ class ChatViewModelTest {
             assertNull(state.sudoPrompt)
             assertNull(state.errorMessage)
             assertNull(state.resumeError)
+            assertNull(state.pendingReasoningLevel)
+            assertNull(state.reasoningWireLevel)
             assertTrue(state.isLoading)
         }
 
+    @Test
+    fun testSessionInfo_reconcilesRequestedAndWireReasoningEffort() =
+        runTest {
+            val (viewModel, sessionId) = createViewModelWithSession()
+            mockEventsFlow.emit(
+                WsEvent.SessionInfo(
+                    data =
+                        mapOf(
+                            "model" to "gpt-5",
+                            "provider" to "openai",
+                            "reasoning_effort" to "ultra",
+                            "reasoning_effort_wire" to "max",
+                        ),
+                    sessionId = sessionId,
+                ),
+            )
+            runCurrent()
+
+            val state = viewModel.uiState.value
+            assertEquals("ultra", state.reasoningLevel)
+            assertEquals("max", state.reasoningWireLevel)
+
+            // Other session's event is ignored
+            mockEventsFlow.emit(
+                WsEvent.SessionInfo(
+                    data =
+                        mapOf(
+                            "model" to "gpt-5",
+                            "provider" to "openai",
+                            "reasoning_effort" to "low",
+                        ),
+                    sessionId = "other-session-id",
+                ),
+            )
+            runCurrent()
+
+            assertEquals("ultra", viewModel.uiState.value.reasoningLevel)
+        }
+
     @Test
     fun testSessionBranchResult_clearsSessionBoundUiState() =
         runTest {
diff --git a/app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerToolbarTest.kt b/app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerToolbarTest.kt
index cd3df878..c5db82da 100644
--- a/app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerToolbarTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/ui/chat/ComposerToolbarTest.kt
@@ -38,4 +38,16 @@ class ComposerToolbarTest {
         assertEquals("openai/", composerModelLabel("openai/", showProvider = true))
         assertEquals("/gpt-5", composerModelLabel("/gpt-5", showProvider = true))
     }
+
+    @Test
+    fun buildReasoningLabel_formatsRequestedAndClampedWire() {
+        assertEquals("Default", buildReasoningLabel(null, defaultLabel = "Default"))
+        assertEquals("الافتراضي", buildReasoningLabel(null, defaultLabel = "الافتراضي"))
+        assertEquals("None", buildReasoningLabel("none"))
+        assertEquals("High", buildReasoningLabel("high"))
+        assertEquals("Ultra", buildReasoningLabel("ultra"))
+        assertEquals("Ultra→Max", buildReasoningLabel("ultra", wireLevel = "max"))
+        assertEquals("High", buildReasoningLabel("high", wireLevel = "high"))
+        assertEquals("None", buildReasoningLabel("none", wireLevel = "low"))
+    }
 }
diff --git a/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatchRpcTest.kt b/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatchRpcTest.kt
index 95c33f4a..f64050d3 100644
--- a/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatchRpcTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatchRpcTest.kt
@@ -237,6 +237,121 @@ class SlashCommandDispatchRpcTest {
             assertEquals("do the thing", userBubble?.content)
         }
 
+    @Test
+    fun `reasoning effort with global flag uses acknowledged CONFIG_SET`() =
+        runTest {
+            val (vm, sessionId) = createViewModelWithSession()
+
+            val methodCalls = mutableListOf<String>()
+            val paramsCalls = mutableListOf<Map<String, Any>>()
+            every {
+                HermesWsClient.request(capture(methodCalls), capture(paramsCalls), any())
+            } answers {
+                val result =
+                    if (arg<String>(0) == WsMethods.CONFIG_SET) {
+                        kotlinx.serialization.json.buildJsonObject {
+                            put("key", kotlinx.serialization.json.JsonPrimitive("reasoning"))
+                            put("value", kotlinx.serialization.json.JsonPrimitive("high"))
+                        }
+                    } else {
+                        kotlinx.serialization.json.JsonNull
+                    }
+                CompletableDeferred<Any?>(result)
+            }
+
+            vm.sendMessage("/reasoning high --global")
+            advanceUntilIdle()
+
+            val configIndex = methodCalls.indexOf(WsMethods.CONFIG_SET)
+            assertTrue("expected CONFIG_SET, got $methodCalls", configIndex >= 0)
+            val params = paramsCalls[configIndex]
+            assertEquals("reasoning", params["key"])
+            assertEquals("high", params["value"])
+            assertEquals(sessionId, params["session_id"])
+            assertEquals("global", params["scope"])
+            assertEquals("high", vm.uiState.value.reasoningLevel)
+            assertTrue(WsMethods.COMMAND_DISPATCH !in methodCalls)
+        }
+
+    @Test
+    fun `reasoning display word uses CONFIG_SET instead of rejecting locally`() =
+        runTest {
+            val (vm, sessionId) = createViewModelWithSession()
+
+            val methodCalls = mutableListOf<String>()
+            val paramsCalls = mutableListOf<Map<String, Any>>()
+            every {
+                HermesWsClient.request(capture(methodCalls), capture(paramsCalls), any())
+            } answers {
+                val result =
+                    if (arg<String>(0) == WsMethods.CONFIG_SET) {
+                        kotlinx.serialization.json.buildJsonObject {
+                            put("key", kotlinx.serialization.json.JsonPrimitive("reasoning"))
+                            put("value", kotlinx.serialization.json.JsonPrimitive("show"))
+                        }
+                    } else {
+                        kotlinx.serialization.json.JsonNull
+                    }
+                CompletableDeferred<Any?>(result)
+            }
+
+            vm.sendMessage("/reasoning show")
+            advanceUntilIdle()
+
+            val configIndex = methodCalls.indexOf(WsMethods.CONFIG_SET)
+            assertTrue("expected CONFIG_SET, got $methodCalls", configIndex >= 0)
+            val params = paramsCalls[configIndex]
+            assertEquals("reasoning", params["key"])
+            assertEquals("show", params["value"])
+            assertEquals(sessionId, params["session_id"])
+            assertTrue(WsMethods.COMMAND_DISPATCH !in methodCalls)
+            assertEquals(
+                "reasoning: show",
+                vm.uiState.value.messages
+                    .lastOrNull { it.role == MessageRole.ASSISTANT }
+                    ?.content,
+            )
+        }
+
+    @Test
+    fun `bare reasoning reads canonical CONFIG_GET status`() =
+        runTest {
+            val (vm, sessionId) = createViewModelWithSession()
+
+            val methodCalls = mutableListOf<String>()
+            val paramsCalls = mutableListOf<Map<String, Any>>()
+            every {
+                HermesWsClient.request(capture(methodCalls), capture(paramsCalls), any())
+            } answers {
+                val result =
+                    if (arg<String>(0) == WsMethods.CONFIG_GET) {
+                        kotlinx.serialization.json.buildJsonObject {
+                            put("value", kotlinx.serialization.json.JsonPrimitive("ultra"))
+                            put("display", kotlinx.serialization.json.JsonPrimitive("hide"))
+                        }
+                    } else {
+                        kotlinx.serialization.json.JsonNull
+                    }
+                CompletableDeferred<Any?>(result)
+            }
+
+            vm.sendMessage("/reasoning")
+            advanceUntilIdle()
+
+            val configIndex = methodCalls.indexOf(WsMethods.CONFIG_GET)
+            assertTrue("expected CONFIG_GET, got $methodCalls", configIndex >= 0)
+            val params = paramsCalls[configIndex]
+            assertEquals("reasoning", params["key"])
+            assertEquals(sessionId, params["session_id"])
+            assertTrue(WsMethods.COMMAND_DISPATCH !in methodCalls)
+            assertEquals(
+                "reasoning: ultra · display hide",
+                vm.uiState.value.messages
+                    .lastOrNull { it.role == MessageRole.ASSISTANT }
+                    ?.content,
+            )
+        }
+
     @Test
     fun `slash queue with no arg shows usage and sends nothing`() =
         runTest {
diff --git a/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcherTest.kt b/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcherTest.kt
index a196f878..b85b4f23 100644
--- a/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcherTest.kt
+++ b/app/src/test/java/com/m57/hermescontrol/ui/chat/SlashCommandDispatcherTest.kt
@@ -53,6 +53,14 @@ class SlashCommandDispatcherTest {
         assertEquals(SlashResult.ModelSwitch, dispatcher.dispatch("/Model"))
     }
 
+    @Test
+    fun `reasoning routes to ReasoningSwitch`() {
+        assertEquals(SlashResult.ReasoningSwitch(""), dispatcher.dispatch("/reasoning"))
+        assertEquals(SlashResult.ReasoningSwitch("high"), dispatcher.dispatch("/reasoning high"))
+        assertEquals(SlashResult.ReasoningSwitch("HIGH"), dispatcher.dispatch("/REASONING HIGH"))
+        assertEquals(SlashResult.ReasoningSwitch("ultra"), dispatcher.dispatch("/Reasoning ultra"))
+    }
+
     @Test
     fun `update routes to Update`() {
         // /update's backend handler is interactive + session-exiting and can