diff --git a/package.json b/package.json
index 3abd448..ed5c46b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hermes-web-ui",
-  "version": "0.5.26",
+  "version": "0.5.27",
   "description": "Self-hosted AI chat dashboard for Hermes Agent — multi-model web UI with multi-platform integration",
   "repository": {
     "type": "git",
diff --git a/packages/client/src/api/hermes/chat.ts b/packages/client/src/api/hermes/chat.ts
index 877c8c2..6f75cc6 100644
--- a/packages/client/src/api/hermes/chat.ts
+++ b/packages/client/src/api/hermes/chat.ts
@@ -16,6 +16,8 @@ export interface StartRunRequest {
   instructions?: string
   session_id?: string
   model?: string
+  provider?: string
+  model_groups?: Array<{ provider: string; models: string[] }>
   queue_id?: string
   source?: 'api_server' | 'cli'
 }
diff --git a/packages/client/src/api/hermes/conversations.ts b/packages/client/src/api/hermes/conversations.ts
index d4d2707..cb7c07f 100644
--- a/packages/client/src/api/hermes/conversations.ts
+++ b/packages/client/src/api/hermes/conversations.ts
@@ -4,6 +4,7 @@ export interface ConversationSummary {
   id: string
   source: string
   model: string
+  provider?: string
   title: string | null
   started_at: number
   ended_at: number | null
diff --git a/packages/client/src/api/hermes/sessions.ts b/packages/client/src/api/hermes/sessions.ts
index 5e463c8..83e5114 100644
--- a/packages/client/src/api/hermes/sessions.ts
+++ b/packages/client/src/api/hermes/sessions.ts
@@ -4,6 +4,7 @@ export interface SessionSummary {
   id: string
   source: string
   model: string
+  provider?: string
   title: string | null
   preview?: string
   started_at: number
@@ -147,6 +148,18 @@ export async function setSessionWorkspace(id: string, workspace: string | null):
   }
 }
 
+export async function setSessionModel(id: string, model: string, provider: string): Promise<boolean> {
+  try {
+    await request(`/api/hermes/sessions/${id}/model`, {
+      method: 'POST',
+      body: JSON.stringify({ model, provider }),
+    })
+    return true
+  } catch {
+    return false
+  }
+}
+
 export async function exportSession(id: string, mode: 'full' | 'compressed' = 'full', ext: 'json' | 'txt' = 'json'): Promise<void> {
   const baseUrl = getBaseUrlValue()
   const token = getApiKey()
diff --git a/packages/client/src/components/hermes/chat/ChatPanel.vue b/packages/client/src/components/hermes/chat/ChatPanel.vue
index accb06b..697ec74 100644
--- a/packages/client/src/components/hermes/chat/ChatPanel.vue
+++ b/packages/client/src/components/hermes/chat/ChatPanel.vue
@@ -1,15 +1,18 @@
 <script setup lang="ts">
 import { renameSession, setSessionWorkspace, batchDeleteSessions, exportSession } from "@/api/hermes/sessions";
 import { useChatStore, type Session } from "@/stores/hermes/chat";
+import { useAppStore } from "@/stores/hermes/app";
 import { useSessionBrowserPrefsStore } from "@/stores/hermes/session-browser-prefs";
 import {
   NButton,
   NDropdown,
   NInput,
   NModal,
+  NSelect,
   NTooltip,
   NPopconfirm,
   useMessage,
+  type DropdownOption,
 } from "naive-ui";
 import { computed, nextTick, onMounted, onUnmounted, ref, watch } from "vue";
 import { useI18n } from "vue-i18n";
@@ -23,6 +26,7 @@ import SessionListItem from "./SessionListItem.vue";
 import DrawerPanel from "./DrawerPanel.vue";
 
 const chatStore = useChatStore();
+const appStore = useAppStore();
 const sessionBrowserPrefsStore = useSessionBrowserPrefsStore();
 const message = useMessage();
 const { t } = useI18n();
@@ -331,15 +335,25 @@ const contextSessionPinned = computed(() =>
     ? sessionBrowserPrefsStore.isPinned(contextSessionId.value)
     : false,
 );
+const contextSession = computed(() =>
+  contextSessionId.value
+    ? chatStore.sessions.find((session) => session.id === contextSessionId.value) || null
+    : null,
+);
 
-const contextMenuOptions = computed(() => [
-  {
+const contextMenuOptions = computed(() => {
+  const options: DropdownOption[] = [{
     label: t(contextSessionPinned.value ? "chat.unpin" : "chat.pin"),
     key: "pin",
   },
   { label: t("chat.rename"), key: "rename" },
-  { label: t("chat.setWorkspace"), key: "workspace" },
-  {
+  { label: t("chat.setWorkspace"), key: "workspace" }]
+
+  if (contextSession.value?.source === "cli") {
+    options.push({ label: t("chat.setModel"), key: "model" })
+  }
+
+  options.push({
     label: t("chat.export"),
     key: "export",
     children: [
@@ -360,9 +374,10 @@ const contextMenuOptions = computed(() => [
         ],
       },
     ],
-  },
-  { label: t("chat.copySessionId"), key: "copy-id" },
-]);
+  })
+  options.push({ label: t("chat.copySessionId"), key: "copy-id" })
+  return options
+});
 
 function handleContextMenu(e: MouseEvent, sessionId: string) {
   e.preventDefault();
@@ -411,6 +426,8 @@ async function handleContextMenuSelect(key: string) {
     workspaceSessionId.value = contextSessionId.value;
     workspaceValue.value = session?.workspace || "";
     showWorkspaceModal.value = true;
+  } else if (key === "model") {
+    openSessionModelModal(contextSessionId.value);
   } else if (key === "rename") {
     const session = chatStore.sessions.find(
       (s) => s.id === contextSessionId.value,
@@ -473,6 +490,98 @@ async function handleWorkspaceConfirm() {
   }
   showWorkspaceModal.value = false;
 }
+
+const showSessionModelModal = ref(false);
+const sessionModelSessionId = ref<string | null>(null);
+const sessionModelSearch = ref("");
+const sessionModelCollapsedGroups = ref<Record<string, boolean>>({});
+const sessionModelValue = ref("");
+const sessionModelProvider = ref("");
+const sessionModelCustomInput = ref("");
+const sessionModelCustomProvider = ref("");
+
+const sessionModelProviderOptions = computed(() =>
+  appStore.modelGroups.map((group) => ({ label: group.label, value: group.provider })),
+);
+
+const sessionModelGroupsWithCustom = computed(() =>
+  appStore.modelGroups.map((group) => ({
+    ...group,
+    models: [
+      ...group.models,
+      ...(appStore.customModels[group.provider] || []).filter(
+        (model) => !group.models.includes(model),
+      ),
+    ],
+  })),
+);
+
+const filteredSessionModelGroups = computed(() => {
+  const query = sessionModelSearch.value.trim().toLowerCase();
+  if (!query) return sessionModelGroupsWithCustom.value;
+  return sessionModelGroupsWithCustom.value
+    .map((group) => ({
+      ...group,
+      models: group.models.filter((model) => {
+        const displayName = appStore.displayModelName(model, group.provider);
+        return model.toLowerCase().includes(query) || displayName.toLowerCase().includes(query);
+      }),
+    }))
+    .filter((group) => group.models.length > 0 || group.label.toLowerCase().includes(query));
+});
+
+function openSessionModelModal(sessionId: string) {
+  const session = chatStore.sessions.find((s) => s.id === sessionId);
+  sessionModelSessionId.value = sessionId;
+  sessionModelValue.value = session?.model || appStore.selectedModel || "";
+  sessionModelProvider.value = session?.provider || appStore.selectedProvider || "";
+  sessionModelCustomProvider.value = sessionModelProvider.value;
+  sessionModelSearch.value = "";
+  sessionModelCustomInput.value = "";
+  sessionModelCollapsedGroups.value = {};
+  showSessionModelModal.value = true;
+}
+
+function isSessionModelGroupCollapsed(provider: string) {
+  return !!sessionModelCollapsedGroups.value[provider];
+}
+
+function toggleSessionModelGroup(provider: string) {
+  sessionModelCollapsedGroups.value[provider] = !sessionModelCollapsedGroups.value[provider];
+}
+
+function isCustomSessionModel(model: string, provider: string) {
+  return (appStore.customModels[provider] || []).includes(model);
+}
+
+function sessionModelDisplayName(model: string, provider: string) {
+  return appStore.displayModelName(model, provider);
+}
+
+function sessionModelAlias(model: string, provider: string) {
+  return appStore.getModelAlias(model, provider);
+}
+
+async function selectSessionModel(model: string, provider: string) {
+  const meta = appStore.modelGroups.find((group) => group.provider === provider)?.model_meta?.[model];
+  if (meta?.disabled || !sessionModelSessionId.value) return;
+  const ok = await chatStore.switchSessionModel(model, provider, sessionModelSessionId.value);
+  if (ok) {
+    sessionModelValue.value = model;
+    sessionModelProvider.value = provider;
+    showSessionModelModal.value = false;
+    message.success(t("chat.modelSet"));
+  } else {
+    message.error(t("chat.modelSetFailed"));
+  }
+}
+
+async function handleSessionModelCustomSubmit() {
+  const model = sessionModelCustomInput.value.trim();
+  const provider = sessionModelCustomProvider.value;
+  if (!model || !provider) return;
+  await selectSessionModel(model, provider);
+}
 </script>
 
 <template>
@@ -737,6 +846,104 @@ async function handleWorkspaceConfirm() {
       <FolderPicker v-model="workspaceValue" />
     </NModal>
 
+    <NModal
+      v-model:show="showSessionModelModal"
+      preset="card"
+      :title="t('chat.setModelTitle')"
+      :style="{ width: 'min(480px, calc(100vw - 32px))' }"
+      :mask-closable="true"
+    >
+      <NInput
+        v-model:value="sessionModelSearch"
+        :placeholder="t('models.searchPlaceholder')"
+        clearable
+        size="small"
+        class="session-model-search"
+      />
+      <div class="session-model-list">
+        <div v-for="group in filteredSessionModelGroups" :key="group.provider" class="session-model-group">
+          <div class="session-model-group-header" @click="toggleSessionModelGroup(group.provider)">
+            <svg
+              class="session-model-group-arrow"
+              :class="{ collapsed: isSessionModelGroupCollapsed(group.provider) }"
+              width="12"
+              height="12"
+              viewBox="0 0 24 24"
+              fill="none"
+              stroke="currentColor"
+              stroke-width="2"
+              stroke-linecap="round"
+              stroke-linejoin="round"
+            >
+              <polyline points="6 9 12 15 18 9" />
+            </svg>
+            <span class="session-model-group-label">{{ group.label }}</span>
+            <span class="session-model-group-count">{{ group.models.length }}</span>
+          </div>
+          <div v-show="!isSessionModelGroupCollapsed(group.provider)" class="session-model-group-items">
+            <div
+              v-for="model in group.models"
+              :key="model"
+              class="session-model-item"
+              :class="{
+                active: model === sessionModelValue && group.provider === sessionModelProvider,
+                disabled: !!group.model_meta?.[model]?.disabled,
+              }"
+              :title="group.model_meta?.[model]?.disabled ? t('models.disabledTooltip') : ''"
+              @click="selectSessionModel(model, group.provider)"
+            >
+              <span class="session-model-item-label">
+                <span class="session-model-item-name">{{ sessionModelDisplayName(model, group.provider) }}</span>
+                <span v-if="sessionModelAlias(model, group.provider)" class="session-model-item-id">
+                  {{ t('models.aliasCanonical', { model }) }}
+                </span>
+              </span>
+              <span v-if="group.model_meta?.[model]?.preview" class="session-model-badge-preview">{{ t('models.previewBadge') }}</span>
+              <span v-if="group.model_meta?.[model]?.disabled" class="session-model-badge-disabled">{{ t('models.disabledBadge') }}</span>
+              <span v-if="isCustomSessionModel(model, group.provider)" class="session-model-badge-custom">{{ t('models.customBadge') }}</span>
+              <svg
+                v-if="model === sessionModelValue && group.provider === sessionModelProvider"
+                class="session-model-check"
+                width="14"
+                height="14"
+                viewBox="0 0 24 24"
+                fill="none"
+                stroke="currentColor"
+                stroke-width="2.5"
+                stroke-linecap="round"
+                stroke-linejoin="round"
+              >
+                <polyline points="20 6 9 17 4 12" />
+              </svg>
+            </div>
+          </div>
+        </div>
+        <div v-if="filteredSessionModelGroups.length === 0" class="session-model-empty">
+          {{ sessionModelSearch ? 'No results' : 'No models' }}
+        </div>
+        <div class="session-model-custom">
+          <div class="session-model-custom-row">
+            <NSelect
+              v-model:value="sessionModelCustomProvider"
+              :options="sessionModelProviderOptions"
+              size="small"
+              class="session-model-custom-provider"
+            />
+            <NInput
+              v-model:value="sessionModelCustomInput"
+              :placeholder="t('models.customModelPlaceholder')"
+              size="small"
+              class="session-model-custom-input"
+              @keydown.enter="handleSessionModelCustomSubmit"
+            />
+          </div>
+          <div class="session-model-custom-hint">
+            {{ t('models.customModelHint') }}
+          </div>
+        </div>
+      </div>
+    </NModal>
+
     <div class="chat-main">
       <header class="chat-header">
         <div class="header-left">
@@ -935,6 +1142,186 @@ async function handleWorkspaceConfirm() {
   position: relative;
 }
 
+.session-model-search {
+  margin-bottom: 12px;
+}
+
+.session-model-list {
+  max-height: 50vh;
+  overflow-y: auto;
+  scrollbar-width: thin;
+}
+
+.session-model-group {
+  margin-bottom: 4px;
+}
+
+.session-model-group-header {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px;
+  font-size: 12px;
+  font-weight: 600;
+  color: $text-secondary;
+  cursor: pointer;
+  border-radius: $radius-sm;
+  user-select: none;
+  transition: background-color $transition-fast;
+
+  &:hover {
+    background-color: $bg-secondary;
+  }
+}
+
+.session-model-group-arrow {
+  flex-shrink: 0;
+  transition: transform $transition-fast;
+
+  &.collapsed {
+    transform: rotate(-90deg);
+  }
+}
+
+.session-model-group-label {
+  flex: 1;
+}
+
+.session-model-group-count {
+  font-size: 11px;
+  color: $text-muted;
+  font-weight: 400;
+}
+
+.session-model-group-items {
+  padding-left: 8px;
+}
+
+.session-model-item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 7px 10px;
+  font-size: 13px;
+  color: $text-secondary;
+  border-radius: $radius-sm;
+  cursor: pointer;
+  transition: all $transition-fast;
+
+  &:hover {
+    background-color: rgba(var(--accent-primary-rgb), 0.06);
+    color: $text-primary;
+  }
+
+  &.active {
+    color: $accent-primary;
+    font-weight: 500;
+  }
+
+  &.disabled {
+    opacity: 0.45;
+    cursor: not-allowed;
+
+    &:hover {
+      background-color: transparent;
+      color: $text-secondary;
+    }
+  }
+}
+
+.session-model-item-label {
+  flex: 1;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+}
+
+.session-model-item-name,
+.session-model-item-id {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  font-family: $font-code;
+}
+
+.session-model-item-name {
+  font-size: 12px;
+}
+
+.session-model-item-id {
+  color: $text-muted;
+  font-size: 10px;
+  font-weight: 400;
+}
+
+.session-model-check {
+  flex-shrink: 0;
+  color: $accent-primary;
+}
+
+.session-model-badge-preview,
+.session-model-badge-custom,
+.session-model-badge-disabled {
+  flex-shrink: 0;
+  font-size: 9px;
+  font-weight: 600;
+  padding: 1px 5px;
+  border-radius: 3px;
+  margin-right: 4px;
+  letter-spacing: 0.03em;
+}
+
+.session-model-badge-preview {
+  color: #fff;
+  background: #d97706;
+}
+
+.session-model-badge-custom {
+  color: #fff;
+  background: $accent-primary;
+}
+
+.session-model-badge-disabled {
+  color: $text-muted;
+  background: transparent;
+  border: 1px solid $border-color;
+  padding: 0 5px;
+}
+
+.session-model-empty {
+  padding: 24px 0;
+  text-align: center;
+  font-size: 13px;
+  color: $text-muted;
+}
+
+.session-model-custom {
+  margin-top: 12px;
+  padding-top: 12px;
+  border-top: 1px solid $border-color;
+}
+
+.session-model-custom-row {
+  display: flex;
+  gap: 8px;
+}
+
+.session-model-custom-provider {
+  width: 160px;
+  flex-shrink: 0;
+}
+
+.session-model-custom-input {
+  flex: 1;
+}
+
+.session-model-custom-hint {
+  margin-top: 6px;
+  font-size: 11px;
+  color: $text-muted;
+}
+
 .session-list {
   width: 220px;
   border-right: 1px solid $border-color;
diff --git a/packages/client/src/components/hermes/chat/ConversationMonitorPane.vue b/packages/client/src/components/hermes/chat/ConversationMonitorPane.vue
index 932a7f2..7c729dc 100644
--- a/packages/client/src/components/hermes/chat/ConversationMonitorPane.vue
+++ b/packages/client/src/components/hermes/chat/ConversationMonitorPane.vue
@@ -1,11 +1,13 @@
 <script setup lang="ts">
 import { fetchConversationDetail, fetchConversationSummaries, type ConversationDetail, type ConversationSummary } from '@/api/hermes/conversations'
 import { formatTimestampSeconds, getSourceLabel } from '@/shared/session-display'
+import { useAppStore } from '@/stores/hermes/app'
 import { computed, onMounted, onUnmounted, ref, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 const props = defineProps<{ humanOnly: boolean }>()
 const { t } = useI18n()
+const appStore = useAppStore()
 
 const POLL_INTERVAL_MS = 15000
 
@@ -20,6 +22,11 @@ let sessionsRequestId = 0
 let detailRequestId = 0
 
 const selectedSession = computed(() => sessions.value.find(session => session.id === selectedSessionId.value) || null)
+const selectedSessionModelName = computed(() =>
+  selectedSession.value?.model
+    ? appStore.displayModelName(selectedSession.value.model, selectedSession.value.provider)
+    : '',
+)
 
 function roleLabel(role: string): string {
   return role === 'user' ? t('chat.monitorRoleUser') : t('chat.monitorRoleAssistant')
@@ -153,7 +160,7 @@ onUnmounted(() => {
         <div class="conversation-monitor__detail-meta">
           <span>{{ getSourceLabel(selectedSession.source) }}</span>
           <span>·</span>
-          <span>{{ selectedSession.model }}</span>
+          <span :title="selectedSession.model">{{ selectedSessionModelName }}</span>
           <span>·</span>
           <span>{{ linkedSessionsLabel(selectedSession.thread_session_count) }}</span>
         </div>
diff --git a/packages/client/src/components/hermes/chat/SessionListItem.vue b/packages/client/src/components/hermes/chat/SessionListItem.vue
index 853b39f..56e7375 100644
--- a/packages/client/src/components/hermes/chat/SessionListItem.vue
+++ b/packages/client/src/components/hermes/chat/SessionListItem.vue
@@ -1,8 +1,9 @@
 <script setup lang="ts">
-import { ref, onUnmounted } from 'vue'
+import { computed, ref, onUnmounted } from 'vue'
 import { NPopconfirm, NCheckbox } from 'naive-ui'
 import { useI18n } from 'vue-i18n'
 import type { Session } from '@/stores/hermes/chat'
+import { useAppStore } from '@/stores/hermes/app'
 import { formatTimestampMs } from '@/shared/session-display'
 
 const props = defineProps<{
@@ -23,6 +24,12 @@ const emit = defineEmits<{
 }>()
 
 const { t } = useI18n()
+const appStore = useAppStore()
+const sessionModelName = computed(() =>
+  props.session.model
+    ? appStore.displayModelName(props.session.model, props.session.provider)
+    : '',
+)
 
 let longPressTimer: ReturnType<typeof setTimeout> | null = null
 const longPressTriggered = ref(false)
@@ -97,7 +104,7 @@ onUnmounted(() => {
         </span>
       </span>
       <span class="session-item-meta">
-        <span v-if="session.model" class="session-item-model">{{ session.model }}</span>
+        <span v-if="sessionModelName" class="session-item-model" :title="session.model">{{ sessionModelName }}</span>
         <span class="session-item-time">{{ formatTimestampMs(session.createdAt) }}</span>
       </span>
     </div>
diff --git a/packages/client/src/components/hermes/models/ProviderCard.vue b/packages/client/src/components/hermes/models/ProviderCard.vue
index acf66fd..97a00aa 100644
--- a/packages/client/src/components/hermes/models/ProviderCard.vue
+++ b/packages/client/src/components/hermes/models/ProviderCard.vue
@@ -130,7 +130,7 @@ async function handleDelete() {
           // 服务端会在默认模型属于 copilot 时清掉 model.default，这里再清理本地
           // 会话级 model/provider，避免 Chat 页继续显示已下架的 copilot 模型。
           chatStore.clearProviderFromSessions('copilot')
-          await Promise.all([modelsStore.fetchProviders(), appStore.loadModels()])
+          await modelsStore.fetchProviders()
         } else {
           await modelsStore.removeProvider(props.provider.provider)
         }
diff --git a/packages/client/src/data/changelog.ts b/packages/client/src/data/changelog.ts
index 0f2921b..f75decb 100644
--- a/packages/client/src/data/changelog.ts
+++ b/packages/client/src/data/changelog.ts
@@ -5,6 +5,16 @@ export interface ChangelogEntry {
 }
 
 export const changelog: ChangelogEntry[] = [
+  {
+    version: '0.5.27',
+    date: '2026-05-17',
+    changes: [
+      'changelog.new_0_5_27_1',
+      'changelog.new_0_5_27_2',
+      'changelog.new_0_5_27_3',
+      'changelog.new_0_5_27_4',
+    ],
+  },
   {
     version: '0.5.26',
     date: '2026-05-17',
diff --git a/packages/client/src/i18n/locales/de.ts b/packages/client/src/i18n/locales/de.ts
index 96e77a7..3c0e72c 100644
--- a/packages/client/src/i18n/locales/de.ts
+++ b/packages/client/src/i18n/locales/de.ts
@@ -932,6 +932,10 @@ jobTriggered: 'Job ausgelost',
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 Tag der Arbeit! Heute wird nicht gearbeitet, bitte habt Verständnis',
     new_0_5_5_2: 'Verlaufsseite für Hermes-Sitzungshistorie hinzugefügt',
     new_0_5_5_3: 'Verlaufsseite verwaltet Sitzungen unabhängig ohne Störung des aktiven Chats',
diff --git a/packages/client/src/i18n/locales/en.ts b/packages/client/src/i18n/locales/en.ts
index 4322d63..57627be 100644
--- a/packages/client/src/i18n/locales/en.ts
+++ b/packages/client/src/i18n/locales/en.ts
@@ -226,6 +226,10 @@ export default {
     workspacePlaceholder: 'Enter project path, e.g. /home/user/project',
     workspaceSet: 'Workspace set',
     workspaceSetFailed: 'Failed to set workspace',
+    setModel: 'Set Model',
+    setModelTitle: 'Set Session Model',
+    modelSet: 'Model set',
+    modelSetFailed: 'Failed to set model',
     other: 'Other',
     runFailed: 'Run failed',
     error: 'Error',
@@ -1224,6 +1228,10 @@ export default {
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
 
     new_0_5_6_1: 'Add voice playback feature with Web Speech API: manual button, auto-play toggle, rainbow border animation, and mobile optimization',
     new_0_5_6_2: 'Add robust LLM JSON parser with tolerance for Python format and extract text from streaming events',
diff --git a/packages/client/src/i18n/locales/es.ts b/packages/client/src/i18n/locales/es.ts
index 9cd51fd..170df80 100644
--- a/packages/client/src/i18n/locales/es.ts
+++ b/packages/client/src/i18n/locales/es.ts
@@ -928,6 +928,10 @@ jobTriggered: 'Job ejecutado',
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 ¡Feliz Día del Trabajo! Hoy no se trabaja, agradezcan su comprensión',
     new_0_5_5_2: 'Añadida página de historial para sesiones Hermes',
     new_0_5_5_3: 'La página de historial gestiona sesiones de forma independiente',
diff --git a/packages/client/src/i18n/locales/fr.ts b/packages/client/src/i18n/locales/fr.ts
index 562ce5d..bc760b2 100644
--- a/packages/client/src/i18n/locales/fr.ts
+++ b/packages/client/src/i18n/locales/fr.ts
@@ -927,6 +927,10 @@ jobTriggered: 'Job declenche',
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 Joyeuse Fête du Travail! Pas de travail aujourd\'hui, merci de votre compréhension',
     new_0_5_5_2: 'Ajout d\'une page d\'historique pour les sessions Hermes',
     new_0_5_5_3: 'La page d\'historique gère les sessions de manière indépendante',
diff --git a/packages/client/src/i18n/locales/ja.ts b/packages/client/src/i18n/locales/ja.ts
index 5a5c19d..95c39ad 100644
--- a/packages/client/src/i18n/locales/ja.ts
+++ b/packages/client/src/i18n/locales/ja.ts
@@ -928,6 +928,10 @@ export default {
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 労働者の日！今日はお休みです、何卒ご理解ください',
     new_0_5_5_2: 'Hermesセッション履歴ページを追加',
     new_0_5_5_3: '履歴ページはアクティブチャットに干渉せずにセッション管理',
diff --git a/packages/client/src/i18n/locales/ko.ts b/packages/client/src/i18n/locales/ko.ts
index 51ede5a..103187c 100644
--- a/packages/client/src/i18n/locales/ko.ts
+++ b/packages/client/src/i18n/locales/ko.ts
@@ -928,6 +928,10 @@ export default {
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 노동절 감사합니다! 오늘은 쉬니까 양해 부탁드립니다',
     new_0_5_5_2: 'Hermes 세션 기록 페이지 추가',
     new_0_5_5_3: '기록 페이지는 독립적으로 세션 관리',
diff --git a/packages/client/src/i18n/locales/pt.ts b/packages/client/src/i18n/locales/pt.ts
index 26545fc..7ccc65c 100644
--- a/packages/client/src/i18n/locales/pt.ts
+++ b/packages/client/src/i18n/locales/pt.ts
@@ -928,6 +928,10 @@ jobTriggered: 'Job acionado',
     new_0_5_26_10: 'Support Hermes Agent package installs when no source checkout is available',
     new_0_5_26_11: 'Add xAI Grok OAuth login for SuperGrok subscription users and update Grok model presets',
     new_0_5_26_12: 'Expand browser, chat streaming, provider, gateway, config, plugin, and Bridge test coverage',
+    new_0_5_27_1: 'Add session-level model settings for Bridge chats, with independent provider and model saved per session',
+    new_0_5_27_2: 'Right-click a Bridge session and choose Set Model to switch the model for that session',
+    new_0_5_27_3: 'Runs now validate the session model and fall back to the current default model when the saved model is unavailable',
+    new_0_5_27_4: 'Context compression now follows the current Profile default selected model by default',
     new_0_5_5_1: '🎉 Feliz Dia do Trabalhador! Hoje não se trabalha, obrigado pela compreensão',
     new_0_5_5_2: 'Adicionada página de histórico para sessões Hermes',
     new_0_5_5_3: 'Página de histórico gerencia sessões de forma independente',
diff --git a/packages/client/src/i18n/locales/zh-TW.ts b/packages/client/src/i18n/locales/zh-TW.ts
index 9079f40..08ba02a 100644
--- a/packages/client/src/i18n/locales/zh-TW.ts
+++ b/packages/client/src/i18n/locales/zh-TW.ts
@@ -1221,6 +1221,10 @@ export default {
     new_0_5_26_10: '支援未找到原始碼目錄時使用套件安裝的 Hermes Agent',
     new_0_5_26_11: '新增 xAI Grok OAuth 登入，支援 SuperGrok 訂閱使用者授權，並更新 Grok 模型預設',
     new_0_5_26_12: '擴展瀏覽器、聊天串流、Provider、Gateway、設定、外掛和 Bridge 測試覆蓋',
+    new_0_5_27_1: '新增 Bridge 工作階段級模型設定，每個工作階段可獨立保存 provider 和 model',
+    new_0_5_27_2: '在 Bridge 工作階段列表中右鍵工作階段，選擇「設定模型」即可為目前工作階段切換模型',
+    new_0_5_27_3: '執行時會自動校驗工作階段模型是否可用；不可用時回退到目前預設模型並更新工作階段',
+    new_0_5_27_4: '上下文壓縮預設跟隨目前 Profile 的預設選中模型',
     new_0_5_6_1: '新增語音播放功能：使用 Web Speech API，支援手動播放按鈕、自動播放開關、彩虹邊框動畫和行動端最佳化',
     new_0_5_6_2: '新增強健的 LLM JSON 解析器，相容 Python 格式並從串流事件中擷取文字',
     new_0_5_6_3: 'Skills 功能增強：使用統計、來源過濾、封存技能、來源追溯和釘選切換',
diff --git a/packages/client/src/i18n/locales/zh.ts b/packages/client/src/i18n/locales/zh.ts
index 450fa14..5ca7272 100644
--- a/packages/client/src/i18n/locales/zh.ts
+++ b/packages/client/src/i18n/locales/zh.ts
@@ -226,6 +226,10 @@ export default {
     workspacePlaceholder: '输入项目路径，例如 /home/user/project',
     workspaceSet: '工作区已设置',
     workspaceSetFailed: '设置工作区失败',
+    setModel: '设置模型',
+    setModelTitle: '设置会话模型',
+    modelSet: '模型已设置',
+    modelSetFailed: '设置模型失败',
     other: '其他',
     runFailed: '运行失败',
     error: '错误',
@@ -1226,6 +1230,10 @@ export default {
     new_0_5_26_10: '支持未找到源码目录时使用包安装的 Hermes Agent',
     new_0_5_26_11: '新增 xAI Grok OAuth 登录，支持 SuperGrok 订阅用户授权，并更新 Grok 模型预设',
     new_0_5_26_12: '扩展浏览器、聊天流式、Provider、Gateway、配置、插件和 Bridge 测试覆盖',
+    new_0_5_27_1: '新增 Bridge 会话级模型设置，每个会话可以独立保存 provider 和 model',
+    new_0_5_27_2: '在 Bridge 会话列表中右键会话，选择“设置模型”即可为当前会话切换模型',
+    new_0_5_27_3: '运行时会自动校验会话模型是否可用；不可用时回退到当前默认模型并更新会话',
+    new_0_5_27_4: '上下文压缩默认跟随当前 Profile 的默认选中模型',
 
     new_0_5_6_1: '新增语音播放功能：使用 Web Speech API，支持手动播放按钮、自动播放开关、彩虹边框动画和移动端优化',
     new_0_5_6_2: '新增健壮的 LLM JSON 解析器，兼容 Python 格式并从流式事件中提取文本',
diff --git a/packages/client/src/stores/hermes/app.ts b/packages/client/src/stores/hermes/app.ts
index b3d6099..8e32ee0 100644
--- a/packages/client/src/stores/hermes/app.ts
+++ b/packages/client/src/stores/hermes/app.ts
@@ -17,6 +17,7 @@ import { hasApiKey } from '@/api/client'
 const WEB_UI_VERSION = __APP_VERSION__
 
 const SIDEBAR_COLLAPSED_KEY = 'hermes_sidebar_collapsed'
+const MODELS_CACHE_TTL_MS = 30000
 
 export const useAppStore = defineStore('app', () => {
   const sidebarOpen = ref(false)
@@ -42,6 +43,8 @@ export const useAppStore = defineStore('app', () => {
   const streamEnabled = ref(true)
   const sessionPersistence = ref(true)
   const maxTokens = ref(4096)
+  let modelsLoadPromise: Promise<void> | null = null
+  let modelsLoadedAt = 0
 
   async function doUpdate(): Promise<boolean> {
     updating.value = true
@@ -128,14 +131,26 @@ export const useAppStore = defineStore('app', () => {
     }
   }
 
-  async function loadModels() {
+  async function loadModels(force = false) {
     if (!hasApiKey()) return
-    try {
-      const res = await fetchAvailableModels()
-      applyAvailableModelsResponse(res)
-    } catch {
-      // ignore
-    }
+    if (!force && modelsLoadPromise) return modelsLoadPromise
+    if (!force && modelGroups.value.length > 0 && Date.now() - modelsLoadedAt < MODELS_CACHE_TTL_MS) return
+    modelsLoadPromise = (async () => {
+      try {
+        const res = await fetchAvailableModels()
+        applyAvailableModelsResponse(res)
+        modelsLoadedAt = Date.now()
+      } catch {
+        // ignore
+      } finally {
+        modelsLoadPromise = null
+      }
+    })()
+    return modelsLoadPromise
+  }
+
+  async function reloadModels() {
+    return loadModels(true)
   }
 
   function getModelAlias(modelId: string, provider?: string): string {
@@ -220,7 +235,7 @@ export const useAppStore = defineStore('app', () => {
   async function setModelVisibility(provider: string, rule: ModelVisibilityRule) {
     const res = await updateModelVisibility({ provider, mode: rule.mode, models: rule.models })
     modelVisibility.value = res.model_visibility || {}
-    await loadModels()
+    await reloadModels()
   }
 
   function startHealthPolling(interval = 30000) {
@@ -285,6 +300,7 @@ export const useAppStore = defineStore('app', () => {
     maxTokens,
     checkConnection,
     loadModels,
+    reloadModels,
     applyAvailableModelsResponse,
     switchModel,
     removeCustomModel,
diff --git a/packages/client/src/stores/hermes/chat.ts b/packages/client/src/stores/hermes/chat.ts
index 7636be9..059909e 100644
--- a/packages/client/src/stores/hermes/chat.ts
+++ b/packages/client/src/stores/hermes/chat.ts
@@ -1,5 +1,5 @@
 import { startRunViaSocket, resumeSession, registerSessionHandlers, unregisterSessionHandlers, getChatRunSocket, respondToolApproval, type RunEvent, type ContentBlock as ContentBlockImport } from '@/api/hermes/chat'
-import { deleteSession as deleteSessionApi, fetchSession, fetchSessions, type HermesMessage, type SessionSummary } from '@/api/hermes/sessions'
+import { deleteSession as deleteSessionApi, fetchSession, fetchSessions, setSessionModel, type HermesMessage, type SessionSummary } from '@/api/hermes/sessions'
 import { getApiKey } from '@/api/client'
 import { defineStore } from 'pinia'
 import { ref, computed } from 'vue'
@@ -238,7 +238,7 @@ function mapHermesSession(s: SessionSummary): Session {
     createdAt: Math.round(s.started_at * 1000),
     updatedAt: Math.round((s.last_active || s.ended_at || s.started_at) * 1000),
     model: s.model,
-    provider: (s as any).billing_provider || '',
+    provider: s.provider || (s as any).billing_provider || '',
     messageCount: s.message_count,
     endedAt: s.ended_at != null ? Math.round(s.ended_at * 1000) : null,
     lastActiveAt: s.last_active != null ? Math.round(s.last_active * 1000) : undefined,
@@ -611,18 +611,25 @@ export const useChatStore = defineStore('chat', () => {
     // Inherit current global model
     const appStore = useAppStore()
     session.model = appStore.selectedModel || undefined
+    session.provider = appStore.selectedProvider || ''
     switchSession(session.id)
   }
 
-  async function switchSessionModel(modelId: string, provider?: string) {
-    if (!activeSession.value) return
-    activeSession.value.model = modelId
-    activeSession.value.provider = provider || ''
-    // If provider changed, update global config too (Hermes requires it)
-    if (provider) {
-      const { useAppStore } = await import('./app')
-      await useAppStore().switchModel(modelId, provider)
+  async function switchSessionModel(modelId: string, provider?: string, sessionId?: string): Promise<boolean> {
+    const targetId = sessionId || activeSession.value?.id
+    if (!targetId) return false
+    const ok = await setSessionModel(targetId, modelId, provider || '')
+    if (!ok) return false
+    const target = sessions.value.find(s => s.id === targetId)
+    if (target) {
+      target.model = modelId
+      target.provider = provider || ''
     }
+    if (activeSession.value?.id === targetId) {
+      activeSession.value.model = modelId
+      activeSession.value.provider = provider || ''
+    }
+    return true
   }
 
   async function deleteSession(sessionId: string) {
@@ -903,13 +910,21 @@ export const useChatStore = defineStore('chat', () => {
       }
 
       const appStore = useAppStore()
+      await appStore.loadModels()
       const sessionModel = activeSession.value?.model || appStore.selectedModel
+      const isBridgeSource = activeSession.value?.source === 'cli'
+      const sessionProvider = activeSession.value?.provider || appStore.selectedProvider
       const runPayload = {
         input,
         session_id: sid,
-        model: sessionModel || undefined,
+        model: isBridgeSource ? undefined : sessionModel || undefined,
+        provider: isBridgeSource ? undefined : sessionProvider || undefined,
+        model_groups: appStore.modelGroups.map(group => ({
+          provider: group.provider,
+          models: group.models,
+        })),
         queue_id: userMsg.id,
-        source: (activeSession.value?.source === 'cli' ? 'cli' : 'api_server') as 'cli' | 'api_server',
+        source: (isBridgeSource ? 'cli' : 'api_server') as 'cli' | 'api_server',
       }
 
       if (shouldQueue) {
diff --git a/packages/client/src/stores/hermes/models.ts b/packages/client/src/stores/hermes/models.ts
index 98c6b7f..a8136ee 100644
--- a/packages/client/src/stores/hermes/models.ts
+++ b/packages/client/src/stores/hermes/models.ts
@@ -52,21 +52,17 @@ export const useModelsStore = defineStore('models', () => {
     await systemApi.updateDefaultModel({ default: modelId, provider })
     defaultModel.value = modelId
     const appStore = useAppStore()
-    appStore.loadModels()
+    appStore.reloadModels()
   }
 
   async function addProvider(data: CustomProvider) {
     await systemApi.addCustomProvider(data)
     await fetchProviders()
-    const appStore = useAppStore()
-    appStore.loadModels()
   }
 
   async function removeProvider(name: string) {
     await systemApi.removeCustomProvider(name)
     await fetchProviders()
-    const appStore = useAppStore()
-    appStore.loadModels()
   }
 
   return {
diff --git a/packages/client/src/views/hermes/ModelsView.vue b/packages/client/src/views/hermes/ModelsView.vue
index caae2d2..0b24c6a 100644
--- a/packages/client/src/views/hermes/ModelsView.vue
+++ b/packages/client/src/views/hermes/ModelsView.vue
@@ -5,19 +5,17 @@ import { useI18n } from 'vue-i18n'
 import ProvidersPanel from '@/components/hermes/models/ProvidersPanel.vue'
 import ProviderFormModal from '@/components/hermes/models/ProviderFormModal.vue'
 import { useModelsStore } from '@/stores/hermes/models'
-import { useAppStore } from '@/stores/hermes/app'
 import { checkCopilotToken } from '@/api/hermes/copilot-auth'
 
 const { t } = useI18n()
 const modelsStore = useModelsStore()
-const appStore = useAppStore()
 const showModal = ref(false)
 
 onMounted(async () => {
   // 先 invalidate 后端 copilot 缓存（gh logout / VS Code 退出后下一次 list 立刻反映），
   // 再拉 providers 与 appStore 的模型显示名配置。check-token 失败不阻断。
   try { await checkCopilotToken() } catch { /* ignore */ }
-  await Promise.all([modelsStore.fetchProviders(), appStore.loadModels()])
+  await modelsStore.fetchProviders()
 })
 
 function openCreateModal() {
@@ -30,7 +28,6 @@ function handleModalClose() {
 
 async function handleSaved() {
   await modelsStore.fetchProviders()
-  appStore.loadModels()
   handleModalClose()
 }
 </script>
diff --git a/packages/server/src/controllers/hermes/sessions.ts b/packages/server/src/controllers/hermes/sessions.ts
index 973bc22..dadc8f3 100644
--- a/packages/server/src/controllers/hermes/sessions.ts
+++ b/packages/server/src/controllers/hermes/sessions.ts
@@ -41,6 +41,7 @@ export async function listConversations(ctx: any) {
     id: s.id,
     source: s.source,
     model: s.model,
+    provider: s.provider,
     title: s.title,
     started_at: s.started_at,
     ended_at: s.ended_at,
@@ -267,6 +268,28 @@ export async function setWorkspace(ctx: any) {
   ctx.body = { ok: true }
 }
 
+export async function setModel(ctx: any) {
+  const { model, provider } = ctx.request.body as { model?: string; provider?: string }
+  if (!model || typeof model !== 'string') {
+    ctx.status = 400
+    ctx.body = { error: 'model is required' }
+    return
+  }
+  if (provider !== undefined && provider !== null && typeof provider !== 'string') {
+    ctx.status = 400
+    ctx.body = { error: 'provider must be a string' }
+    return
+  }
+  const { updateSession, getSession, createSession } = await import('../../db/hermes/session-store')
+  const { getActiveProfileName } = await import('../../services/hermes/hermes-profile')
+  const id = ctx.params.id
+  if (!getSession(id)) {
+    createSession({ id, profile: getActiveProfileName(), title: '' })
+  }
+  updateSession(id, { model: model.trim(), provider: (provider || '').trim() } as any)
+  ctx.body = { ok: true }
+}
+
 export async function contextLength(ctx: any) {
   const profile = (ctx.query.profile as string) || undefined
   ctx.body = { context_length: getModelContextLength(profile) }
diff --git a/packages/server/src/db/hermes/schemas.ts b/packages/server/src/db/hermes/schemas.ts
index b2c2547..ab31953 100644
--- a/packages/server/src/db/hermes/schemas.ts
+++ b/packages/server/src/db/hermes/schemas.ts
@@ -34,6 +34,7 @@ export const SESSIONS_SCHEMA: Record<string, string> = {
   source: 'TEXT NOT NULL DEFAULT \'api_server\'',
   user_id: 'TEXT',
   model: 'TEXT NOT NULL DEFAULT \'\'',
+  provider: 'TEXT NOT NULL DEFAULT \'\'',
   title: 'TEXT',
   started_at: 'INTEGER NOT NULL',
   ended_at: 'INTEGER',
diff --git a/packages/server/src/db/hermes/session-store.ts b/packages/server/src/db/hermes/session-store.ts
index f6f52cc..8eafa87 100644
--- a/packages/server/src/db/hermes/session-store.ts
+++ b/packages/server/src/db/hermes/session-store.ts
@@ -12,6 +12,7 @@ export interface HermesSessionRow {
   source: string
   user_id: string | null
   model: string
+  provider: string
   title: string | null
   started_at: number
   ended_at: number | null
@@ -85,6 +86,7 @@ function mapSessionRow(row: Record<string, unknown>): HermesSessionRow {
     source: String(row.source || 'api_server'),
     user_id: row.user_id != null ? String(row.user_id) : null,
     model: String(row.model || ''),
+    provider: String(row.provider || ''),
     title,
     started_at: Number(row.started_at || 0),
     ended_at: row.ended_at != null ? Number(row.ended_at) : null,
@@ -131,6 +133,7 @@ export function createSession(data: {
   profile?: string
   source?: string
   model?: string
+  provider?: string
   title?: string
   workspace?: string
 }): HermesSessionRow {
@@ -139,7 +142,7 @@ export function createSession(data: {
   if (!isSqliteAvailable()) {
     return {
       id: data.id, profile: data.profile || 'default', source,
-      user_id: null, model: data.model || '', title: data.title || null,
+      user_id: null, model: data.model || '', provider: data.provider || '', title: data.title || null,
       started_at: now, ended_at: null, end_reason: null,
       message_count: 0, tool_call_count: 0,
       input_tokens: 0, output_tokens: 0, cache_read_tokens: 0, cache_write_tokens: 0, reasoning_tokens: 0,
@@ -149,9 +152,9 @@ export function createSession(data: {
   }
   const db = getDb()!
   db.prepare(
-    `INSERT INTO ${SESSIONS_TABLE} (id, profile, source, model, title, started_at, last_active, workspace)
-     VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
-  ).run(data.id, data.profile || 'default', source, data.model || '', data.title || null, now, now, data.workspace || null)
+    `INSERT INTO ${SESSIONS_TABLE} (id, profile, source, model, provider, title, started_at, last_active, workspace)
+     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+  ).run(data.id, data.profile || 'default', source, data.model || '', data.provider || '', data.title || null, now, now, data.workspace || null)
   return getSession(data.id)!
 }
 
diff --git a/packages/server/src/routes/hermes/sessions.ts b/packages/server/src/routes/hermes/sessions.ts
index 7768fa1..57c8476 100644
--- a/packages/server/src/routes/hermes/sessions.ts
+++ b/packages/server/src/routes/hermes/sessions.ts
@@ -21,4 +21,5 @@ sessionRoutes.delete('/api/hermes/sessions/:id', ctrl.remove)
 sessionRoutes.post('/api/hermes/sessions/batch-delete', ctrl.batchRemove)
 sessionRoutes.post('/api/hermes/sessions/:id/rename', ctrl.rename)
 sessionRoutes.post('/api/hermes/sessions/:id/workspace', ctrl.setWorkspace)
+sessionRoutes.post('/api/hermes/sessions/:id/model', ctrl.setModel)
 sessionRoutes.get('/api/hermes/workspace/folders', ctrl.listWorkspaceFolders)
diff --git a/packages/server/src/services/hermes/agent-bridge/client.ts b/packages/server/src/services/hermes/agent-bridge/client.ts
index acc9ad1..18eccd9 100644
--- a/packages/server/src/services/hermes/agent-bridge/client.ts
+++ b/packages/server/src/services/hermes/agent-bridge/client.ts
@@ -28,6 +28,13 @@ export interface AgentBridgeRequestOptions {
   timeoutMs?: number
 }
 
+export interface AgentBridgeChatOptions {
+  force_compress?: boolean
+  storage_message?: AgentBridgeMessage
+  model?: string
+  provider?: string
+}
+
 export type AgentBridgeMessage =
   | string
   | Array<Record<string, unknown>>
@@ -306,7 +313,7 @@ export class AgentBridgeClient {
     conversationHistory?: unknown[],
     instructions?: string,
     profile?: string,
-    options: { force_compress?: boolean; storage_message?: AgentBridgeMessage } = {},
+    options: AgentBridgeChatOptions = {},
   ): Promise<AgentBridgeChatStarted> {
     return this.request<AgentBridgeChatStarted>({
       action: 'chat',
@@ -316,6 +323,8 @@ export class AgentBridgeClient {
       ...(conversationHistory ? { conversation_history: conversationHistory } : {}),
       ...(instructions ? { instructions } : {}),
       ...(profile ? { profile } : {}),
+      ...(options.model ? { model: options.model } : {}),
+      ...(options.provider ? { provider: options.provider } : {}),
       ...(options.force_compress ? { force_compress: true } : {}),
     })
   }
diff --git a/packages/server/src/services/hermes/agent-bridge/hermes_bridge.py b/packages/server/src/services/hermes/agent-bridge/hermes_bridge.py
index 8c34270..a403f37 100644
--- a/packages/server/src/services/hermes/agent-bridge/hermes_bridge.py
+++ b/packages/server/src/services/hermes/agent-bridge/hermes_bridge.py
@@ -491,12 +491,21 @@ class AgentPool:
         self,
         session_id: str,
         profile: str | None = None,
+        model: str | None = None,
+        provider: str | None = None,
     ) -> AgentSession:
+        requested_model = str(model or "").strip()
+        requested_provider = str(provider or "").strip()
         with self._lock:
             existing = self._sessions.get(session_id)
             if existing is not None:
                 # If profile changed, destroy old session and recreate
-                if profile and existing.config.get("profile") != profile:
+                config_changed = bool(
+                    (profile and existing.config.get("profile") != profile)
+                    or (requested_model and existing.config.get("model") != requested_model)
+                    or (requested_provider and existing.config.get("provider") != requested_provider)
+                )
+                if config_changed:
                     if not existing.running:
                         self._destroy_session(session_id)
                     else:
@@ -512,8 +521,8 @@ class AgentPool:
 
             with _profile_env(profile):
                 cfg = _load_cfg()
-                resolved_model = _resolve_model(cfg)
-                runtime = _resolve_runtime(resolved_model)
+                resolved_model = requested_model or _resolve_model(cfg)
+                runtime = _resolve_runtime(resolved_model, requested_provider or None)
                 agent_cfg = cfg.get("agent") or {}
                 prompt = str(agent_cfg.get("system_prompt", "") or "").strip() or None
 
@@ -949,8 +958,10 @@ class AgentPool:
         conversation_history: list[dict[str, Any]] | None = None,
         profile: str | None = None,
         force_compress: bool = False,
+        model: str | None = None,
+        provider: str | None = None,
     ) -> RunRecord:
-        session = self.get_or_create(session_id, profile=profile)
+        session = self.get_or_create(session_id, profile=profile, model=model, provider=provider)
         with session.lock:
             if session.running:
                 raise RuntimeError(f"session {session_id} is already running")
@@ -1265,6 +1276,8 @@ class BridgeServer:
             instructions = req.get("instructions") or req.get("system_message")
             conversation_history = req.get("conversation_history")
             profile = req.get("profile")
+            model = req.get("model")
+            provider = req.get("provider")
             record = self.pool.start_chat(
                 session_id,
                 message,
@@ -1273,6 +1286,8 @@ class BridgeServer:
                 conversation_history,
                 profile,
                 bool(req.get("force_compress")),
+                model,
+                provider,
             )
             if req.get("wait"):
                 timeout = float(req.get("timeout", 0) or 0)
diff --git a/packages/server/src/services/hermes/run-chat/handle-api-run.ts b/packages/server/src/services/hermes/run-chat/handle-api-run.ts
index 2e07c5f..3f12a10 100644
--- a/packages/server/src/services/hermes/run-chat/handle-api-run.ts
+++ b/packages/server/src/services/hermes/run-chat/handle-api-run.ts
@@ -75,14 +75,14 @@ export async function loadSessionStateFromDb(sid: string, _sessionMap: Map<strin
 export async function handleApiRun(
   nsp: ReturnType<Server['of']>,
   socket: Socket,
-  data: { input: string | ContentBlock[]; session_id?: string; model?: string; instructions?: string; source?: string },
+  data: { input: string | ContentBlock[]; session_id?: string; model?: string; provider?: string; instructions?: string; source?: string },
   profile: string,
   sessionMap: Map<string, SessionState>,
   gatewayManager: any,
   skipUserMessage = false,
   dequeueNextQueuedRun: (socket: Socket, sessionId: string, fallbackProfile?: string) => void,
 ) {
-  const { input, session_id, model, instructions } = data
+  const { input, session_id, model, provider, instructions } = data
 
   // Build full instructions with system prompt + workspace context
   let fullInstructions = instructions
@@ -131,7 +131,7 @@ export async function handleApiRun(
       if (!getSession(session_id)) {
         const previewText = extractTextForPreview(input)
         const preview = previewText.replace(/[\r\n]/g, ' ').substring(0, 100)
-        createSession({ id: session_id, profile, source: 'api_server', model, title: preview })
+        createSession({ id: session_id, profile, source: 'api_server', model, provider, title: preview })
       }
 
       addMessage({
@@ -153,7 +153,7 @@ export async function handleApiRun(
       if (!getSession(session_id)) {
         const previewText = extractTextForPreview(input)
         const preview = previewText.replace(/[\r\n]/g, ' ').substring(0, 100)
-        createSession({ id: session_id, profile, source: 'api_server', model, title: preview })
+        createSession({ id: session_id, profile, source: 'api_server', model, provider, title: preview })
       }
       addMessage({
         session_id,
diff --git a/packages/server/src/services/hermes/run-chat/handle-bridge-run.ts b/packages/server/src/services/hermes/run-chat/handle-bridge-run.ts
index eab43a9..538d4d3 100644
--- a/packages/server/src/services/hermes/run-chat/handle-bridge-run.ts
+++ b/packages/server/src/services/hermes/run-chat/handle-bridge-run.ts
@@ -5,10 +5,11 @@
 
 import type { Server, Socket } from 'socket.io'
 import { getSystemPrompt } from '../../../lib/llm-prompt'
-import { getSession, createSession, addMessage, updateSessionStats } from '../../../db/hermes/session-store'
+import { getSession, createSession, addMessage, updateSession, updateSessionStats } from '../../../db/hermes/session-store'
 import { updateUsage } from '../../../db/hermes/usage-store'
 import { logger, bridgeLogger } from '../../logger'
 import { AgentBridgeClient, type AgentBridgeMessage, type AgentBridgeOutput } from '../agent-bridge'
+import { readConfigYaml } from '../../config-helpers'
 import { contentBlocksToString, convertContentBlocksForAgent, extractTextForPreview, isContentBlockArray } from './content-blocks'
 import { buildCompressedHistory } from './compression'
 import { pushState, replaceState } from './compression'
@@ -29,10 +30,34 @@ import type { ChatMessage } from '../../../lib/context-compressor'
 
 const BRIDGE_USAGE_FLUSH_DELAY_MS = 200
 
+type RunModelGroup = { provider: string; models: string[] }
+
+async function resolveDefaultModelConfig(): Promise<{ model: string; provider: string }> {
+  try {
+    const config = await readConfigYaml()
+    const modelConfig = config?.model
+    const model = typeof modelConfig === 'string'
+      ? modelConfig.trim()
+      : String(modelConfig?.default || '').trim()
+    const provider = typeof modelConfig === 'object'
+      ? String(modelConfig?.provider || '').trim()
+      : ''
+    return { model, provider }
+  } catch {
+    return { model: '', provider: '' }
+  }
+}
+
+function hasModelInGroups(groups: RunModelGroup[] | undefined, provider: string, model: string): boolean {
+  if (!groups?.length || !provider || !model) return false
+  const group = groups.find(item => item.provider === provider)
+  return Array.isArray(group?.models) && group.models.includes(model)
+}
+
 export async function handleBridgeRun(
   nsp: ReturnType<Server['of']>,
   socket: Socket,
-  data: { input: string | ContentBlock[]; session_id?: string; model?: string; instructions?: string; source?: string },
+  data: { input: string | ContentBlock[]; session_id?: string; model?: string; provider?: string; model_groups?: RunModelGroup[]; instructions?: string; source?: string },
   profile: string,
   sessionMap: Map<string, SessionState>,
   gatewayManager: any,
@@ -41,7 +66,7 @@ export async function handleBridgeRun(
   loadSessionStateFromDbFn: (sid: string, sessionMap: Map<string, SessionState>) => Promise<SessionState>,
   dequeueNextQueuedRun: (socket: Socket, sessionId: string, fallbackProfile?: string) => void,
 ) {
-  const { input, session_id, model, instructions } = data
+  const { input, session_id, instructions } = data
   if (!session_id) {
     socket.emit('run.failed', { event: 'run.failed', error: 'session_id is required for cli source' })
     return
@@ -51,6 +76,22 @@ export async function handleBridgeRun(
     ? `${getSystemPrompt()}\n${instructions}`
     : getSystemPrompt()
   const sessionRow = getSession(session_id)
+  const sessionModel = sessionRow?.model || ''
+  const sessionProvider = sessionRow?.provider || ''
+  const hasGroups = Array.isArray(data.model_groups) && data.model_groups.length > 0
+  const sessionModelAvailable = hasGroups && hasModelInGroups(data.model_groups, sessionProvider, sessionModel)
+  const shouldUseDefault = !sessionModel || !sessionProvider || !sessionModelAvailable
+  const defaultModelConfig = shouldUseDefault
+    ? await resolveDefaultModelConfig()
+    : { model: '', provider: '' }
+  const resolvedModel = shouldUseDefault ? defaultModelConfig.model : sessionModel
+  const resolvedProvider = shouldUseDefault ? defaultModelConfig.provider : sessionProvider
+  if (sessionRow) {
+    const updates: { model?: string; provider?: string } = {}
+    if (resolvedModel && sessionRow.model !== resolvedModel) updates.model = resolvedModel
+    if (resolvedProvider && sessionRow.provider !== resolvedProvider) updates.provider = resolvedProvider
+    if (Object.keys(updates).length > 0) updateSession(session_id, updates)
+  }
   if (sessionRow?.workspace) {
     const workspaceCtx = `[Current working directory: ${sessionRow.workspace}]`
     fullInstructions = `\n${workspaceCtx}\n${fullInstructions}`
@@ -93,7 +134,7 @@ export async function handleBridgeRun(
   if (!getSession(session_id)) {
     const previewText = extractTextForPreview(input)
     const preview = previewText.replace(/[\r\n]/g, ' ').substring(0, 100)
-    createSession({ id: session_id, profile, source: 'cli', model, title: preview })
+    createSession({ id: session_id, profile, source: 'cli', model: resolvedModel, provider: resolvedProvider, title: preview })
   }
   addMessage({
     session_id,
@@ -142,7 +183,11 @@ export async function handleBridgeRun(
       bridgeHistory,
       fullInstructions,
       profile,
-      bridgeStorageInput !== undefined ? { storage_message: bridgeStorageInput } : {},
+      {
+        ...(bridgeStorageInput !== undefined ? { storage_message: bridgeStorageInput } : {}),
+        ...(resolvedModel ? { model: resolvedModel } : {}),
+        ...(resolvedProvider ? { provider: resolvedProvider } : {}),
+      },
     )
     state.runId = started.run_id
     bridgeLogger.info({
diff --git a/packages/server/src/services/hermes/run-chat/index.ts b/packages/server/src/services/hermes/run-chat/index.ts
index ec308da..4518398 100644
--- a/packages/server/src/services/hermes/run-chat/index.ts
+++ b/packages/server/src/services/hermes/run-chat/index.ts
@@ -66,6 +66,8 @@ export class ChatRunSocket {
       session_id?: string
       model?: string
       instructions?: string
+      provider?: string
+      model_groups?: Array<{ provider: string; models: string[] }>
       queue_id?: string
       source?: string
     }) => {
@@ -102,6 +104,8 @@ export class ChatRunSocket {
             queue_id: data.queue_id || `queue_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 8)}`,
             input: data.input,
             model: data.model,
+            provider: data.provider,
+            model_groups: data.model_groups,
             instructions: data.instructions,
             profile: currentProfile(),
             source,
@@ -191,7 +195,15 @@ export class ChatRunSocket {
 
   private async handleRun(
     socket: Socket,
-    data: { input: string | ContentBlock[]; session_id?: string; model?: string; instructions?: string; source?: string },
+    data: {
+      input: string | ContentBlock[]
+      session_id?: string
+      model?: string
+      provider?: string
+      model_groups?: Array<{ provider: string; models: string[] }>
+      instructions?: string
+      source?: string
+    },
     profile: string,
     skipUserMessage = false,
   ) {
@@ -273,6 +285,8 @@ export class ChatRunSocket {
       input: next.input,
       session_id: sessionId,
       model: next.model,
+      provider: next.provider,
+      model_groups: next.model_groups,
       instructions: next.instructions,
       source: next.source,
     }, next.profile || fallbackProfile, true)
diff --git a/packages/server/src/services/hermes/run-chat/types.ts b/packages/server/src/services/hermes/run-chat/types.ts
index 0e89f36..074af64 100644
--- a/packages/server/src/services/hermes/run-chat/types.ts
+++ b/packages/server/src/services/hermes/run-chat/types.ts
@@ -29,6 +29,8 @@ export interface QueuedRun {
   queue_id: string
   input: string | ContentBlock[]
   model?: string
+  provider?: string
+  model_groups?: Array<{ provider: string; models: string[] }>
   instructions?: string
   profile: string
   source?: ChatRunSource
diff --git a/tests/client/conversation-monitor-pane.test.ts b/tests/client/conversation-monitor-pane.test.ts
index 5b7aeb5..813b9c8 100644
--- a/tests/client/conversation-monitor-pane.test.ts
+++ b/tests/client/conversation-monitor-pane.test.ts
@@ -1,6 +1,7 @@
 // @vitest-environment jsdom
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { mount } from '@vue/test-utils'
+import { createPinia, setActivePinia } from 'pinia'
 
 const mockConversationsApi = vi.hoisted(() => ({
   fetchConversationSummaries: vi.fn(),
@@ -38,6 +39,7 @@ function deferred<T>() {
 describe('ConversationMonitorPane', () => {
   beforeEach(() => {
     vi.clearAllMocks()
+    setActivePinia(createPinia())
     vi.useFakeTimers()
     mockConversationsApi.fetchConversationSummaries.mockResolvedValue([
       {
diff --git a/tests/server/sessions-controller.test.ts b/tests/server/sessions-controller.test.ts
index bb02d15..2fe0445 100644
--- a/tests/server/sessions-controller.test.ts
+++ b/tests/server/sessions-controller.test.ts
@@ -12,6 +12,8 @@ const localGetSessionDetailMock = vi.fn()
 const localSearchSessionsMock = vi.fn()
 const localDeleteSessionMock = vi.fn()
 const localRenameSessionMock = vi.fn()
+const localCreateSessionMock = vi.fn()
+const localUpdateSessionMock = vi.fn()
 const getGroupChatServerMock = vi.fn()
 const getLocalUsageStatsMock = vi.fn()
 const getActiveProfileNameMock = vi.fn()
@@ -55,6 +57,9 @@ vi.mock('../../packages/server/src/db/hermes/session-store', () => ({
   getSessionDetail: localGetSessionDetailMock,
   deleteSession: localDeleteSessionMock,
   renameSession: localRenameSessionMock,
+  createSession: localCreateSessionMock,
+  getSession: getSessionMock,
+  updateSession: localUpdateSessionMock,
 }))
 
 vi.mock('../../packages/server/src/db/hermes/usage-store', () => ({
@@ -110,6 +115,8 @@ describe('session conversations controller', () => {
     localSearchSessionsMock.mockReset()
     localDeleteSessionMock.mockReset()
     localRenameSessionMock.mockReset()
+    localCreateSessionMock.mockReset()
+    localUpdateSessionMock.mockReset()
     getGroupChatServerMock.mockReset()
     getGroupChatServerMock.mockReturnValue(null)
     getLocalUsageStatsMock.mockReset()
@@ -296,6 +303,22 @@ describe('session conversations controller', () => {
     ])
   })
 
+  it('sets a session model and provider in the local session store', async () => {
+    getSessionMock.mockReturnValue({ id: 'session-1' })
+
+    const mod = await import('../../packages/server/src/controllers/hermes/sessions')
+    const ctx: any = {
+      params: { id: 'session-1' },
+      request: { body: { model: 'grok-4', provider: 'xai' } },
+      body: null,
+    }
+    await mod.setModel(ctx)
+
+    expect(localCreateSessionMock).not.toHaveBeenCalled()
+    expect(localUpdateSessionMock).toHaveBeenCalledWith('session-1', { model: 'grok-4', provider: 'xai' })
+    expect(ctx.body).toEqual({ ok: true })
+  })
+
   describe('exportSession', () => {
     it('returns session as JSON download with correct headers (full mode)', async () => {
       const sessionData = { id: 'abc-123', title: 'Test Session', messages: [{ id: 1, role: 'user', content: 'hello' }] }
diff --git a/tests/server/sessions-routes.test.ts b/tests/server/sessions-routes.test.ts
index 9e8211d..72f032e 100644
--- a/tests/server/sessions-routes.test.ts
+++ b/tests/server/sessions-routes.test.ts
@@ -11,6 +11,7 @@ const getMock = vi.fn(async (ctx: any) => { ctx.body = { session: { id: ctx.para
 const removeMock = vi.fn(async (ctx: any) => { ctx.body = { ok: true } })
 const renameMock = vi.fn(async (ctx: any) => { ctx.body = { ok: true } })
 const setWorkspaceMock = vi.fn(async (ctx: any) => { ctx.body = { ok: true } })
+const setModelMock = vi.fn(async (ctx: any) => { ctx.body = { ok: true } })
 const listWorkspaceFoldersMock = vi.fn(async (ctx: any) => { ctx.body = { folders: [] } })
 const usageBatchMock = vi.fn(async (ctx: any) => { ctx.body = {} })
 const usageSingleMock = vi.fn(async (ctx: any) => { ctx.body = { input_tokens: 0, output_tokens: 0 } })
@@ -32,6 +33,7 @@ vi.mock('../../packages/server/src/controllers/hermes/sessions', () => ({
   batchRemove: batchRemoveMock,
   rename: renameMock,
   setWorkspace: setWorkspaceMock,
+  setModel: setModelMock,
   listWorkspaceFolders: listWorkspaceFoldersMock,
   usageBatch: usageBatchMock,
   usageSingle: usageSingleMock,
@@ -51,6 +53,7 @@ describe('session routes', () => {
     getMock.mockClear()
     removeMock.mockClear()
     renameMock.mockClear()
+    setModelMock.mockClear()
   })
 
   it('registers conversations, session list, and search routes', async () => {
@@ -71,6 +74,7 @@ describe('session routes', () => {
       '/api/hermes/sessions/:id/export',
       '/api/hermes/sessions/:id/usage',
       '/api/hermes/sessions/:id/rename',
+      '/api/hermes/sessions/:id/model',
     ]))
   })