diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8715ae1..952c3e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,10 @@ version with its date and start a fresh empty `[Unreleased]` above it.
   view (plan credits with edition badge, personal/add-on resource
   pack, organization resource package, renewal date) and links to the
   edition's account usage page.
+- Send/stop action button in the chat composer: a round button at the
+  end of the input toolbar sends the message (same path as Enter),
+  turns into a stop control while a response is streaming (same path
+  as Esc), and stays disabled while the composer is empty.
 - Qoder CLI edition switch in settings (Setup section): choose the
   international build (`qodercli`, config under `~/.qoder`) or the
   China build (`qoderclicn`, config under `~/.qoder-cn`). Auto-
diff --git a/src/features/chat/tabs/tab.ts b/src/features/chat/tabs/tab.ts
index 8c7e507..bd5808f 100644
--- a/src/features/chat/tabs/tab.ts
+++ b/src/features/chat/tabs/tab.ts
@@ -28,6 +28,7 @@ import { BangBashService } from '../services/bang-bash-service';
 import { SubagentManager } from '../services/subagent-manager';
 import { ChatState } from '../state/chat-state';
 import { BangBashModeManager as BangBashModeManagerClass } from '../ui/bang-bash-mode-manager';
+import { ComposerActionButton } from '../ui/composer-action-button';
 import { FileContextManager } from '../ui/file-context/file-context-manager';
 import { ImageContextManager } from '../ui/image-context';
 import { createInputToolbar } from '../ui/input-toolbar';
@@ -152,6 +153,7 @@ export function createTab(options: TabCreateOptions): TabData {
       externalContextSelector: null,
       mcpServerSelector: null,
       permissionToggle: null,
+      composerActionButton: null,
       slashCommandDropdown: null,
       instructionModeManager: null,
       bangBashModeManager: null,
@@ -283,6 +285,7 @@ function initializeContextManagers(tab: TabData, plugin: QoderianPlugin): void {
         tab.controllers.canvasSelectionController?.updateContextRowVisibility();
         autoResizeTextarea(dom.inputEl);
         tab.renderer?.scrollToBottomIfNeeded();
+        updateComposerSendAvailability(tab);
       },
     },
     dom.contextRowEl
@@ -365,6 +368,14 @@ function isBangBashEnabled(plugin: QoderianPlugin): boolean {
   return getQoderSettings(plugin.settings).enableBangBash;
 }
 
+/** Refreshes the send button's enabled state based on composer content. */
+function updateComposerSendAvailability(tab: TabData): void {
+  const hasContent =
+    tab.dom.inputEl.value.trim().length > 0 ||
+    (tab.ui.imageContextManager?.hasImages() ?? false);
+  tab.ui.composerActionButton?.updateSendAvailability(hasContent);
+}
+
 /**
  * Creates and wires the input toolbar for a tab.
  */
@@ -482,6 +493,33 @@ function initializeInputToolbar(
   tab.ui.mcpServerSelector = toolbarComponents.mcpServerSelector;
   tab.ui.permissionToggle = toolbarComponents.permissionToggle;
 
+  // Send/stop action button pinned to the end of the toolbar row.
+  // Clicking it is equivalent to pressing Enter (or Esc while streaming).
+  tab.ui.composerActionButton = new ComposerActionButton(inputToolbar, {
+    onSend: () => {
+      // Instruction/bang modes own the Enter key; route through the same
+      // keydown path so their submit logic applies.
+      if (
+        tab.ui.instructionModeManager?.isActive() ||
+        tab.ui.bangBashModeManager?.isActive()
+      ) {
+        dom.inputEl.dispatchEvent(
+          new KeyboardEvent('keydown', { key: 'Enter', bubbles: true, cancelable: true }),
+        );
+        return;
+      }
+      void tab.controllers.inputController?.sendMessage();
+    },
+    onStop: () => {
+      tab.controllers.inputController?.cancelStreaming();
+    },
+  });
+
+  const updateSendAvailability = () => updateComposerSendAvailability(tab);
+  dom.inputEl.addEventListener('input', updateSendAvailability);
+  dom.eventCleanups.push(() => dom.inputEl.removeEventListener('input', updateSendAvailability));
+  updateSendAvailability();
+
   tab.ui.mcpServerSelector.setMcpManager(getQoderMcpManager(plugin));
 
   // Sync @-mentions to UI selector
@@ -567,8 +605,20 @@ export function initializeTabUI(
   initializeInputModes(tab, plugin);
   initializeInputToolbar(tab, plugin, options.getQoderCatalogConfig);
 
+  // Chain onto the previously registered streaming callback (tab bar
+  // indicator) so the action button tracks streaming state too.
+  const previousStreamingCallback = state.callbacks.onStreamingStateChanged;
   state.callbacks = {
     ...state.callbacks,
+    onStreamingStateChanged: (isStreaming) => {
+      previousStreamingCallback?.(isStreaming);
+      tab.ui.composerActionButton?.setStreaming(isStreaming);
+      if (!isStreaming) {
+        // The composer may have been cleared programmatically (no input
+        // event); re-evaluate send availability when streaming ends.
+        updateComposerSendAvailability(tab);
+      }
+    },
     onUsageChanged: (usage) => {
       tab.ui.contextUsageMeter?.update(usage);
     },
diff --git a/src/features/chat/tabs/types.ts b/src/features/chat/tabs/types.ts
index e1bbcc5..59d1d97 100644
--- a/src/features/chat/tabs/types.ts
+++ b/src/features/chat/tabs/types.ts
@@ -15,6 +15,7 @@ import type { MessageRenderer } from '../rendering/message-renderer';
 import type { SubagentManager } from '../services/subagent-manager';
 import type { ChatState } from '../state/chat-state';
 import type { BangBashModeManager } from '../ui/bang-bash-mode-manager';
+import type { ComposerActionButton } from '../ui/composer-action-button';
 import type { FileContextManager } from '../ui/file-context/file-context-manager';
 import type { ImageContextManager } from '../ui/image-context';
 import type {
@@ -121,6 +122,7 @@ export interface TabUIComponents {
   externalContextSelector: ExternalContextSelector | null;
   mcpServerSelector: McpServerSelector | null;
   permissionToggle: PermissionToggle | null;
+  composerActionButton: ComposerActionButton | null;
   slashCommandDropdown: SlashCommandDropdown | null;
   instructionModeManager: InstructionModeManager | null;
   bangBashModeManager: BangBashModeManager | null;
diff --git a/src/features/chat/ui/composer-action-button.ts b/src/features/chat/ui/composer-action-button.ts
new file mode 100644
index 0000000..42d08cf
--- /dev/null
+++ b/src/features/chat/ui/composer-action-button.ts
@@ -0,0 +1,77 @@
+import { setIcon } from 'obsidian';
+
+import { t } from '../../../i18n/i18n';
+
+export interface ComposerActionButtonCallbacks {
+  /** Sends the current composer content (same path as the Enter key). */
+  onSend: () => void;
+  /** Interrupts the active stream (same path as Escape). */
+  onStop: () => void;
+}
+
+/**
+ * Send/stop action button at the end of the input toolbar.
+ * Shows a send arrow while idle and switches to a stop square while streaming.
+ */
+export class ComposerActionButton {
+  private buttonEl: HTMLButtonElement;
+  private iconEl: HTMLElement;
+  private callbacks: ComposerActionButtonCallbacks;
+  private streaming = false;
+  private sendEnabled = false;
+
+  constructor(parentEl: HTMLElement, callbacks: ComposerActionButtonCallbacks) {
+    this.callbacks = callbacks;
+    this.buttonEl = parentEl.createEl('button', {
+      cls: 'qoderian-composer-action-btn',
+      attr: { type: 'button' },
+    });
+    this.iconEl = this.buttonEl.createSpan({ cls: 'qoderian-composer-action-btn-icon' });
+
+    this.buttonEl.addEventListener('click', (e) => {
+      e.stopPropagation();
+      if (this.streaming) {
+        this.callbacks.onStop();
+      } else if (this.sendEnabled) {
+        this.callbacks.onSend();
+      }
+    });
+
+    this.setStreaming(false);
+    this.updateSendAvailability(false);
+  }
+
+  /** Switches between send (idle) and stop (streaming) modes. */
+  setStreaming(streaming: boolean): void {
+    this.streaming = streaming;
+    this.buttonEl.empty();
+    this.iconEl = this.buttonEl.createSpan({ cls: 'qoderian-composer-action-btn-icon' });
+    if (streaming) {
+      setIcon(this.iconEl, 'square');
+      this.buttonEl.addClass('is-stop');
+      this.buttonEl.toggleClass('is-disabled', false);
+      this.buttonEl.disabled = false;
+      this.buttonEl.setAttribute('aria-label', t('composer.stop'));
+      this.buttonEl.setAttribute('title', t('composer.stop'));
+    } else {
+      setIcon(this.iconEl, 'arrow-up');
+      this.buttonEl.removeClass('is-stop');
+      this.buttonEl.setAttribute('aria-label', t('composer.send'));
+      this.buttonEl.setAttribute('title', t('composer.send'));
+      this.applySendEnabled();
+    }
+  }
+
+  /** Updates whether the composer has sendable content (text or images). */
+  updateSendAvailability(hasContent: boolean): void {
+    this.sendEnabled = hasContent;
+    if (!this.streaming) {
+      this.applySendEnabled();
+    }
+  }
+
+  private applySendEnabled(): void {
+    this.buttonEl.toggleClass('is-disabled', !this.sendEnabled);
+    this.buttonEl.disabled = !this.sendEnabled;
+  }
+}
diff --git a/src/i18n/locales/de.json b/src/i18n/locales/de.json
index ec8289d..807469e 100644
--- a/src/i18n/locales/de.json
+++ b/src/i18n/locales/de.json
@@ -21,6 +21,10 @@
     "refresh": "Aktualisieren",
     "rewind": "Zurückspulen"
   },
+  "composer": {
+    "send": "Nachricht senden",
+    "stop": "Generierung stoppen"
+  },
   "commands": {
     "openView": "Chat-Ansicht öffnen",
     "inlineEdit": "Inline-Bearbeitung",
diff --git a/src/i18n/locales/en.json b/src/i18n/locales/en.json
index f59186b..09fe464 100644
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -21,6 +21,10 @@
     "refresh": "Refresh",
     "rewind": "Rewind"
   },
+  "composer": {
+    "send": "Send message",
+    "stop": "Stop generation"
+  },
   "commands": {
     "openView": "Open chat view",
     "inlineEdit": "Inline edit",
diff --git a/src/i18n/locales/es.json b/src/i18n/locales/es.json
index 2de1e2b..0c3051b 100644
--- a/src/i18n/locales/es.json
+++ b/src/i18n/locales/es.json
@@ -21,6 +21,10 @@
     "refresh": "Actualizar",
     "rewind": "Rebobinar"
   },
+  "composer": {
+    "send": "Enviar mensaje",
+    "stop": "Detener generación"
+  },
   "commands": {
     "openView": "Abrir vista de chat",
     "inlineEdit": "Edición en línea",
diff --git a/src/i18n/locales/fr.json b/src/i18n/locales/fr.json
index 98c8346..f91c9f6 100644
--- a/src/i18n/locales/fr.json
+++ b/src/i18n/locales/fr.json
@@ -21,6 +21,10 @@
     "refresh": "Actualiser",
     "rewind": "Rembobiner"
   },
+  "composer": {
+    "send": "Envoyer le message",
+    "stop": "Arrêter la génération"
+  },
   "commands": {
     "openView": "Ouvrir la vue de discussion",
     "inlineEdit": "Édition en ligne",
diff --git a/src/i18n/locales/ja.json b/src/i18n/locales/ja.json
index 3c2e077..7dc3572 100644
--- a/src/i18n/locales/ja.json
+++ b/src/i18n/locales/ja.json
@@ -21,6 +21,10 @@
     "refresh": "更新",
     "rewind": "巻き戻し"
   },
+  "composer": {
+    "send": "メッセージを送信",
+    "stop": "生成を停止"
+  },
   "commands": {
     "openView": "チャットビューを開く",
     "inlineEdit": "インライン編集",
diff --git a/src/i18n/locales/ko.json b/src/i18n/locales/ko.json
index 924c839..7033a0f 100644
--- a/src/i18n/locales/ko.json
+++ b/src/i18n/locales/ko.json
@@ -21,6 +21,10 @@
     "refresh": "새로고침",
     "rewind": "되감기"
   },
+  "composer": {
+    "send": "메시지 보내기",
+    "stop": "생성 중지"
+  },
   "commands": {
     "openView": "채팅 뷰 열기",
     "inlineEdit": "인라인 편집",
diff --git a/src/i18n/locales/pt.json b/src/i18n/locales/pt.json
index 4b21da9..a7d637d 100644
--- a/src/i18n/locales/pt.json
+++ b/src/i18n/locales/pt.json
@@ -21,6 +21,10 @@
     "refresh": "Atualizar",
     "rewind": "Retroceder"
   },
+  "composer": {
+    "send": "Enviar mensagem",
+    "stop": "Parar geração"
+  },
   "commands": {
     "openView": "Abrir visualização de chat",
     "inlineEdit": "Edição inline",
diff --git a/src/i18n/locales/ru.json b/src/i18n/locales/ru.json
index a79b7b0..f240c8c 100644
--- a/src/i18n/locales/ru.json
+++ b/src/i18n/locales/ru.json
@@ -21,6 +21,10 @@
     "refresh": "Обновить",
     "rewind": "Откатить"
   },
+  "composer": {
+    "send": "Отправить сообщение",
+    "stop": "Остановить генерацию"
+  },
   "commands": {
     "openView": "Открыть представление чата",
     "inlineEdit": "Встроенное редактирование",
diff --git a/src/i18n/locales/zh-CN.json b/src/i18n/locales/zh-CN.json
index 61c6f87..5309a52 100644
--- a/src/i18n/locales/zh-CN.json
+++ b/src/i18n/locales/zh-CN.json
@@ -21,6 +21,10 @@
     "refresh": "刷新",
     "rewind": "回退"
   },
+  "composer": {
+    "send": "发送消息",
+    "stop": "停止生成"
+  },
   "commands": {
     "openView": "打开聊天视图",
     "inlineEdit": "内联编辑",
diff --git a/src/i18n/locales/zh-TW.json b/src/i18n/locales/zh-TW.json
index 8090038..22cb72e 100644
--- a/src/i18n/locales/zh-TW.json
+++ b/src/i18n/locales/zh-TW.json
@@ -21,6 +21,10 @@
     "refresh": "重新整理",
     "rewind": "回退"
   },
+  "composer": {
+    "send": "傳送訊息",
+    "stop": "停止生成"
+  },
   "commands": {
     "openView": "開啟聊天視圖",
     "inlineEdit": "行內編輯",
diff --git a/src/i18n/types.ts b/src/i18n/types.ts
index 196aa7f..777a5a8 100644
--- a/src/i18n/types.ts
+++ b/src/i18n/types.ts
@@ -33,6 +33,10 @@ export type TranslationKey =
   | 'common.refresh'
   | 'common.rewind'
 
+  // Composer - send/stop action button
+  | 'composer.send'
+  | 'composer.stop'
+
   // Chat - Rewind
   | 'chat.rewind.confirmMessage'
   | 'chat.rewind.confirmMessageConversationOnly'
diff --git a/src/style/components/input.css b/src/style/components/input.css
index 588084c..0627146 100644
--- a/src/style/components/input.css
+++ b/src/style/components/input.css
@@ -345,6 +345,59 @@
   height: 14px;
 }
 
+/* Send/stop action button - IDE-style green rounded square with dark icon */
+.qoderian-composer-action-btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  width: 28px;
+  height: 28px;
+  padding: 0;
+  border: none;
+  border-radius: 8px;
+  cursor: pointer;
+  transition: filter 0.15s ease, opacity 0.15s ease;
+}
+
+/* Obsidian's native button defaults (interactive-normal gray) out-specify a
+   single class; raise specificity instead of !important to override them. */
+.qoderian-input-wrapper .qoderian-input-toolbar button.qoderian-composer-action-btn {
+  border: none;
+  box-shadow: none;
+  background: var(--qoderian-brand);
+  color: rgba(0, 0, 0, 0.7);
+}
+
+/* When the permission toggle is hidden the button inherits the row's
+   right alignment instead of sitting next to the left group. */
+.qoderian-permission-toggle.qoderian-hidden ~ .qoderian-composer-action-btn {
+  margin-inline-start: auto;
+}
+
+.qoderian-composer-action-btn:hover:not(:disabled) {
+  filter: brightness(1.08);
+}
+
+.qoderian-composer-action-btn svg {
+  width: 16px;
+  height: 16px;
+}
+
+/* Stop mode: filled square icon, slightly emphasized */
+.qoderian-composer-action-btn.is-stop svg {
+  width: 14px;
+  height: 14px;
+  fill: currentColor;
+}
+
+/* Idle with empty composer: dimmed, not clickable */
+.qoderian-composer-action-btn.is-disabled,
+.qoderian-composer-action-btn:disabled {
+  opacity: 0.4;
+  cursor: default;
+}
+
 /* Light blue border when instruction mode is active */
 .qoderian-input-wrapper.qoderian-input-instruction-mode {
   --qoderian-input-wrapper-border-color: #60a5fa;
diff --git a/tests/unit/features/chat/ui/composer-action-button.test.ts b/tests/unit/features/chat/ui/composer-action-button.test.ts
new file mode 100644
index 0000000..0e55dfe
--- /dev/null
+++ b/tests/unit/features/chat/ui/composer-action-button.test.ts
@@ -0,0 +1,68 @@
+import { createMockEl } from '@test/helpers/mock-element';
+
+import { ComposerActionButton } from '@/features/chat/ui/composer-action-button';
+
+describe('ComposerActionButton', () => {
+  function createButton() {
+    const parentEl = createMockEl();
+    const onSend = jest.fn();
+    const onStop = jest.fn();
+    const button = new ComposerActionButton(parentEl, { onSend, onStop });
+    const buttonEl = parentEl.querySelector('.qoderian-composer-action-btn');
+    if (!buttonEl) throw new Error('action button missing');
+    return { button, buttonEl, onSend, onStop };
+  }
+
+  it('starts disabled with the send label', () => {
+    const { buttonEl } = createButton();
+
+    expect(buttonEl.disabled).toBe(true);
+    expect(buttonEl.hasClass('is-disabled')).toBe(true);
+    expect(buttonEl.getAttribute('title')).toBe('Send message');
+  });
+
+  it('enables once the composer has content and sends on click', () => {
+    const { button, buttonEl, onSend } = createButton();
+
+    button.updateSendAvailability(true);
+    expect(buttonEl.disabled).toBe(false);
+
+    buttonEl.click();
+    expect(onSend).toHaveBeenCalledTimes(1);
+  });
+
+  it('ignores clicks while disabled', () => {
+    const { buttonEl, onSend } = createButton();
+
+    buttonEl.click();
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('switches to stop mode while streaming and routes clicks to stop', () => {
+    const { button, buttonEl, onSend, onStop } = createButton();
+    button.updateSendAvailability(true);
+
+    button.setStreaming(true);
+    expect(buttonEl.disabled).toBe(false);
+    expect(buttonEl.hasClass('is-stop')).toBe(true);
+    expect(buttonEl.getAttribute('title')).toBe('Stop generation');
+
+    buttonEl.click();
+    expect(onStop).toHaveBeenCalledTimes(1);
+    expect(onSend).not.toHaveBeenCalled();
+  });
+
+  it('re-applies send availability when streaming ends', () => {
+    const { button, buttonEl } = createButton();
+
+    button.setStreaming(true);
+    button.setStreaming(false);
+    expect(buttonEl.disabled).toBe(true);
+    expect(buttonEl.hasClass('is-stop')).toBe(false);
+
+    button.updateSendAvailability(true);
+    button.setStreaming(true);
+    button.setStreaming(false);
+    expect(buttonEl.disabled).toBe(false);
+  });
+});