diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000000..5cf366bcb9
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,15 @@
+.git
+.github
+.gcp
+bundle
+evals
+integration-tests
+docs
+packages/cli
+packages/vscode-ide-companion
+packages/test-utils
+**/*.test.ts
+**/*.test.js
+**/src/**/*.ts
+!packages/a2a-server/dist/**
+!packages/core/dist/**
diff --git a/packages/a2a-server/Dockerfile b/packages/a2a-server/Dockerfile
new file mode 100644
index 0000000000..c5014281e6
--- /dev/null
+++ b/packages/a2a-server/Dockerfile
@@ -0,0 +1,28 @@
+# Pre-built production image for a2a-server
+# Used with Cloud Build: npm install + build runs in step 1, then Docker copies artifacts
+FROM docker.io/library/node:20-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  python3 curl git jq ripgrep ca-certificates \
+  && apt-get clean && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Copy everything including pre-installed node_modules and pre-built dist
+COPY package.json package-lock.json ./
+COPY node_modules/ node_modules/
+COPY packages/core/ packages/core/
+COPY packages/a2a-server/ packages/a2a-server/
+
+# Create workspace directory for agent operations
+RUN mkdir -p /workspace && chown -R node:node /workspace
+
+USER node
+
+ENV CODER_AGENT_WORKSPACE_PATH=/workspace
+ENV CODER_AGENT_PORT=8080
+ENV NODE_ENV=production
+
+EXPOSE 8080
+
+CMD ["node", "packages/a2a-server/dist/src/http/server.js"]
diff --git a/packages/a2a-server/cloudbuild.yaml b/packages/a2a-server/cloudbuild.yaml
new file mode 100644
index 0000000000..13459b8752
--- /dev/null
+++ b/packages/a2a-server/cloudbuild.yaml
@@ -0,0 +1,35 @@
+steps:
+  # Step 1: Install all dependencies and build
+  - name: 'node:20-slim'
+    entrypoint: 'bash'
+    args:
+      - '-c'
+      - |
+        apt-get update && apt-get install -y python3 make g++ git
+        npm pkg delete scripts.prepare
+        npm install
+        npm run build
+    env:
+      - 'HUSKY=0'
+
+  # Step 2: Build Docker image (using pre-built dist/ from step 1)
+  - name: 'gcr.io/cloud-builders/docker'
+    args:
+      - 'build'
+      - '-t'
+      - 'us-central1-docker.pkg.dev/$PROJECT_ID/gemini-a2a/a2a-server:latest'
+      - '-f'
+      - 'packages/a2a-server/Dockerfile'
+      - '.'
+
+  # Step 3: Push to Artifact Registry
+  - name: 'gcr.io/cloud-builders/docker'
+    args:
+      - 'push'
+      - 'us-central1-docker.pkg.dev/$PROJECT_ID/gemini-a2a/a2a-server:latest'
+
+images:
+  - 'us-central1-docker.pkg.dev/$PROJECT_ID/gemini-a2a/a2a-server:latest'
+timeout: '1800s'
+options:
+  machineType: 'E2_HIGHCPU_8'
diff --git a/packages/a2a-server/k8s/deployment.yaml b/packages/a2a-server/k8s/deployment.yaml
new file mode 100644
index 0000000000..bda37203d3
--- /dev/null
+++ b/packages/a2a-server/k8s/deployment.yaml
@@ -0,0 +1,72 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: gemini-a2a-server
+  labels:
+    app: gemini-a2a-server
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: gemini-a2a-server
+  template:
+    metadata:
+      labels:
+        app: gemini-a2a-server
+    spec:
+      containers:
+        - name: a2a-server
+          image: us-central1-docker.pkg.dev/adamfweidman-test/gemini-a2a/a2a-server:latest
+          ports:
+            - containerPort: 8080
+              protocol: TCP
+          env:
+            - name: CODER_AGENT_PORT
+              value: "8080"
+            - name: CODER_AGENT_HOST
+              value: "0.0.0.0"
+            - name: CODER_AGENT_WORKSPACE_PATH
+              value: "/workspace"
+            - name: GEMINI_API_KEY
+              valueFrom:
+                secretKeyRef:
+                  name: gemini-secrets
+                  key: api-key
+            - name: GEMINI_YOLO_MODE
+              value: "true"
+            - name: NODE_ENV
+              value: "production"
+          resources:
+            requests:
+              cpu: "500m"
+              memory: "512Mi"
+            limits:
+              cpu: "2000m"
+              memory: "2Gi"
+          readinessProbe:
+            httpGet:
+              path: /.well-known/agent-card.json
+              port: 8080
+            initialDelaySeconds: 10
+            periodSeconds: 10
+          livenessProbe:
+            httpGet:
+              path: /.well-known/agent-card.json
+              port: 8080
+            initialDelaySeconds: 15
+            periodSeconds: 30
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: gemini-a2a-server
+  labels:
+    app: gemini-a2a-server
+spec:
+  type: ClusterIP
+  selector:
+    app: gemini-a2a-server
+  ports:
+    - port: 80
+      targetPort: 8080
+      protocol: TCP
diff --git a/packages/a2a-server/src/a2ui/a2ui-components.ts b/packages/a2a-server/src/a2ui/a2ui-components.ts
new file mode 100644
index 0000000000..348f19231f
--- /dev/null
+++ b/packages/a2a-server/src/a2ui/a2ui-components.ts
@@ -0,0 +1,157 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Builder functions for A2UI standard catalog components.
+ * These create the component objects that go into updateComponents messages.
+ */
+
+import type { A2UIComponent } from './a2ui-extension.js';
+
+// Layout components
+
+export function column(
+  id: string,
+  children: string[],
+  opts?: { align?: string; justify?: string; weight?: number },
+): A2UIComponent {
+  return {
+    id,
+    component: 'Column',
+    children,
+    ...opts,
+  };
+}
+
+export function row(
+  id: string,
+  children: string[],
+  opts?: { align?: string; justify?: string },
+): A2UIComponent {
+  return {
+    id,
+    component: 'Row',
+    children,
+    ...opts,
+  };
+}
+
+export function card(
+  id: string,
+  child: string,
+  opts?: Record<string, unknown>,
+): A2UIComponent {
+  return {
+    id,
+    component: 'Card',
+    child,
+    ...opts,
+  };
+}
+
+// Content components
+
+export function text(
+  id: string,
+  textContent: string | { path: string },
+  opts?: { variant?: string },
+): A2UIComponent {
+  return {
+    id,
+    component: 'Text',
+    text: textContent,
+    ...opts,
+  };
+}
+
+export function icon(id: string, name: string): A2UIComponent {
+  return {
+    id,
+    component: 'Icon',
+    name,
+  };
+}
+
+export function divider(
+  id: string,
+  axis: 'horizontal' | 'vertical' = 'horizontal',
+): A2UIComponent {
+  return {
+    id,
+    component: 'Divider',
+    axis,
+  };
+}
+
+// Interactive components
+
+export function button(
+  id: string,
+  child: string,
+  action: {
+    event?: { name: string; context: Record<string, unknown> };
+    functionCall?: { call: string; args: Record<string, unknown> };
+  },
+  opts?: { variant?: 'primary' | 'borderless' },
+): A2UIComponent {
+  return {
+    id,
+    component: 'Button',
+    child,
+    action,
+    ...opts,
+  };
+}
+
+export function textField(
+  id: string,
+  label: string,
+  valuePath: string,
+  opts?: {
+    variant?: 'shortText' | 'longText';
+    checks?: Array<{
+      call: string;
+      args: Record<string, unknown>;
+      message: string;
+    }>;
+  },
+): A2UIComponent {
+  return {
+    id,
+    component: 'TextField',
+    label,
+    value: { path: valuePath },
+    ...opts,
+  };
+}
+
+export function checkBox(
+  id: string,
+  label: string,
+  valuePath: string,
+): A2UIComponent {
+  return {
+    id,
+    component: 'CheckBox',
+    label,
+    value: { path: valuePath },
+  };
+}
+
+export function choicePicker(
+  id: string,
+  options: Array<{ label: string; value: string }>,
+  valuePath: string,
+  opts?: { variant?: 'mutuallyExclusive' | 'multiSelect' },
+): A2UIComponent {
+  return {
+    id,
+    component: 'ChoicePicker',
+    options,
+    value: { path: valuePath },
+    ...opts,
+  };
+}
diff --git a/packages/a2a-server/src/a2ui/a2ui-extension.ts b/packages/a2a-server/src/a2ui/a2ui-extension.ts
new file mode 100644
index 0000000000..604519974b
--- /dev/null
+++ b/packages/a2a-server/src/a2ui/a2ui-extension.ts
@@ -0,0 +1,194 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * A2UI (Agent-to-UI) Extension for A2A protocol.
+ * Implements the A2UI v0.10 specification for generating declarative UI
+ * messages that clients can render natively.
+ *
+ * @see https://a2ui.org/specification/v0_10/docs/a2ui_protocol.md
+ * @see https://a2ui.org/specification/v0_10/docs/a2ui_extension_specification.md
+ */
+
+import type { Part } from '@a2a-js/sdk';
+
+// Extension constants
+export const A2UI_EXTENSION_URI = 'https://a2ui.org/a2a-extension/a2ui/v0.10';
+export const A2UI_MIME_TYPE = 'application/json+a2ui';
+export const A2UI_VERSION = 'v0.10';
+export const STANDARD_CATALOG_ID =
+  'https://a2ui.org/specification/v0_10/standard_catalog.json';
+
+// Metadata keys
+export const MIME_TYPE_KEY = 'mimeType';
+export const A2UI_CLIENT_CAPABILITIES_KEY = 'a2uiClientCapabilities';
+export const A2UI_CLIENT_DATA_MODEL_KEY = 'a2uiClientDataModel';
+
+/**
+ * A2UI message types (server-to-client).
+ */
+export interface CreateSurfaceMessage {
+  version: typeof A2UI_VERSION;
+  createSurface: {
+    surfaceId: string;
+    catalogId: string;
+    theme?: Record<string, unknown>;
+    sendDataModel?: boolean;
+  };
+}
+
+export interface UpdateComponentsMessage {
+  version: typeof A2UI_VERSION;
+  updateComponents: {
+    surfaceId: string;
+    components: A2UIComponent[];
+  };
+}
+
+export interface UpdateDataModelMessage {
+  version: typeof A2UI_VERSION;
+  updateDataModel: {
+    surfaceId: string;
+    path?: string;
+    value?: unknown;
+  };
+}
+
+export interface DeleteSurfaceMessage {
+  version: typeof A2UI_VERSION;
+  deleteSurface: {
+    surfaceId: string;
+  };
+}
+
+export type A2UIServerMessage =
+  | CreateSurfaceMessage
+  | UpdateComponentsMessage
+  | UpdateDataModelMessage
+  | DeleteSurfaceMessage;
+
+/**
+ * A2UI component definition.
+ */
+export interface A2UIComponent {
+  id: string;
+  component: string;
+  [key: string]: unknown;
+}
+
+/**
+ * A2UI client-to-server action message.
+ */
+export interface A2UIActionMessage {
+  version: typeof A2UI_VERSION;
+  action: {
+    name: string;
+    surfaceId: string;
+    sourceComponentId: string;
+    timestamp: string;
+    context: Record<string, unknown>;
+  };
+}
+
+/**
+ * A2UI client capabilities sent in metadata.
+ */
+export interface A2UIClientCapabilities {
+  supportedCatalogIds: string[];
+  inlineCatalogs?: unknown[];
+}
+
+/**
+ * Creates an A2A DataPart containing A2UI messages.
+ * Per the spec, the data field contains an ARRAY of A2UI messages.
+ */
+export function createA2UIPart(messages: A2UIServerMessage[]): Part {
+   
+  return {
+    kind: 'data',
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    data: messages as unknown as Record<string, unknown>,
+    metadata: {
+      [MIME_TYPE_KEY]: A2UI_MIME_TYPE,
+    },
+  } as Part;
+}
+
+/**
+ * Creates a single A2A DataPart from one A2UI message.
+ */
+export function createA2UISinglePart(message: A2UIServerMessage): Part {
+  return createA2UIPart([message]);
+}
+
+/**
+ * Checks if an A2A Part contains A2UI data.
+ */
+export function isA2UIPart(part: Part): boolean {
+  return (
+    part.kind === 'data' &&
+    part.metadata != null &&
+    part.metadata[MIME_TYPE_KEY] === A2UI_MIME_TYPE
+  );
+}
+
+/**
+ * Extracts A2UI action messages from an A2A Part.
+ */
+export function extractA2UIActions(part: Part): A2UIActionMessage[] {
+  if (!isA2UIPart(part)) return [];
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const data = (part as unknown as { data?: unknown[] }).data;
+  if (!Array.isArray(data)) return [];
+  return data.filter(
+    (msg): msg is A2UIActionMessage =>
+      typeof msg === 'object' &&
+      msg !== null &&
+      'action' in msg &&
+      'version' in msg,
+  );
+}
+
+/**
+ * Creates the A2UI AgentExtension configuration for the AgentCard.
+ */
+export function getA2UIAgentExtension(
+  supportedCatalogIds: string[] = [STANDARD_CATALOG_ID],
+  acceptsInlineCatalogs = false,
+): {
+  uri: string;
+  description: string;
+  required: boolean;
+  params: Record<string, unknown>;
+} {
+  const params: Record<string, unknown> = {};
+  if (supportedCatalogIds.length > 0) {
+    params['supportedCatalogIds'] = supportedCatalogIds;
+  }
+  if (acceptsInlineCatalogs) {
+    params['acceptsInlineCatalogs'] = true;
+  }
+
+  return {
+    uri: A2UI_EXTENSION_URI,
+    description: 'Provides agent driven UI using the A2UI JSON format.',
+    required: false,
+    params,
+  };
+}
+
+/**
+ * Checks if the A2UI extension was requested via extension headers or message.
+ */
+export function isA2UIRequested(
+  requestedExtensions?: string[],
+  messageExtensions?: string[],
+): boolean {
+  return (
+    (requestedExtensions?.includes(A2UI_EXTENSION_URI) ?? false) ||
+    (messageExtensions?.includes(A2UI_EXTENSION_URI) ?? false)
+  );
+}
diff --git a/packages/a2a-server/src/a2ui/a2ui-surface-manager.ts b/packages/a2a-server/src/a2ui/a2ui-surface-manager.ts
new file mode 100644
index 0000000000..1e933a6530
--- /dev/null
+++ b/packages/a2a-server/src/a2ui/a2ui-surface-manager.ts
@@ -0,0 +1,468 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Manages A2UI surfaces for the Gemini CLI A2A server.
+ * Creates and updates surfaces for:
+ * - Tool call approval UIs
+ * - Agent text/thought streaming displays
+ * - Task status indicators
+ */
+
+import type { Part } from '@a2a-js/sdk';
+import { logger } from '../utils/logger.js';
+import {
+  A2UI_VERSION,
+  STANDARD_CATALOG_ID,
+  createA2UIPart,
+  type A2UIServerMessage,
+  type A2UIComponent,
+} from './a2ui-extension.js';
+import {
+  column,
+  row,
+  text,
+  button,
+  card,
+  icon,
+  divider,
+} from './a2ui-components.js';
+
+/**
+ * Generates A2UI parts for tool call approval surfaces.
+ */
+export function createToolCallApprovalSurface(
+  taskId: string,
+  toolCall: {
+    callId: string;
+    name: string;
+    displayName?: string;
+    description?: string;
+    args?: Record<string, unknown>;
+    kind?: string;
+  },
+): Part {
+  const surfaceId = `tool_approval_${taskId}_${toolCall.callId}`;
+  const toolDisplayName = toolCall.displayName || toolCall.name;
+  const argsPreview = toolCall.args
+    ? JSON.stringify(toolCall.args, null, 2).substring(0, 500)
+    : 'No arguments';
+
+  logger.info(
+    `[A2UI] Creating tool approval surface: ${surfaceId} for tool: ${toolDisplayName}`,
+  );
+
+  const messages: A2UIServerMessage[] = [
+    // 1. Create the surface
+    {
+      version: A2UI_VERSION,
+      createSurface: {
+        surfaceId,
+        catalogId: STANDARD_CATALOG_ID,
+        theme: {
+          primaryColor: '#1a73e8',
+          agentDisplayName: 'Gemini CLI Agent',
+        },
+        sendDataModel: true,
+      },
+    },
+    // 2. Define the components
+    {
+      version: A2UI_VERSION,
+      updateComponents: {
+        surfaceId,
+        components: buildToolApprovalComponents(
+          taskId,
+          toolCall.callId,
+          toolDisplayName,
+          toolCall.description || '',
+          argsPreview,
+          toolCall.kind || 'tool',
+        ),
+      },
+    },
+    // 3. Populate the data model
+    {
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId,
+        value: {
+          tool: {
+            callId: toolCall.callId,
+            name: toolCall.name,
+            displayName: toolDisplayName,
+            description: toolCall.description || '',
+            args: argsPreview,
+            kind: toolCall.kind || 'tool',
+            status: 'awaiting_approval',
+          },
+          taskId,
+        },
+      },
+    },
+  ];
+
+  return createA2UIPart(messages);
+}
+
+function buildToolApprovalComponents(
+  taskId: string,
+  callId: string,
+  toolName: string,
+  description: string,
+  argsPreview: string,
+  kind: string,
+): A2UIComponent[] {
+  return [
+    // Root card
+    card('root', 'main_column'),
+
+    // Main vertical layout
+    column(
+      'main_column',
+      [
+        'header_row',
+        'description_text',
+        'divider_1',
+        'args_label',
+        'args_text',
+        'divider_2',
+        'action_row',
+      ],
+      { align: 'stretch' },
+    ),
+
+    // Header with icon and tool name
+    row('header_row', ['tool_icon', 'tool_name_text'], {
+      align: 'center',
+    }),
+    icon('tool_icon', kind === 'shell' ? 'terminal' : 'build'),
+    text('tool_name_text', `**${toolName}** requires approval`, {
+      variant: 'h3',
+    }),
+
+    // Description
+    text(
+      'description_text',
+      description || 'This tool needs your permission to execute.',
+    ),
+
+    divider('divider_1'),
+
+    // Arguments preview
+    text('args_label', '**Arguments:**', { variant: 'caption' }),
+    text('args_text', `\`\`\`\n${argsPreview}\n\`\`\``),
+
+    divider('divider_2'),
+
+    // Action buttons row
+    row(
+      'action_row',
+      ['approve_button', 'approve_always_button', 'reject_button'],
+      { justify: 'spaceBetween' },
+    ),
+
+    // Approve button
+    text('approve_label', 'Approve'),
+    button(
+      'approve_button',
+      'approve_label',
+      {
+        event: {
+          name: 'tool_confirmation',
+          context: {
+            taskId,
+            callId,
+            outcome: 'proceed_once',
+          },
+        },
+      },
+      { variant: 'primary' },
+    ),
+
+    // Approve always button
+    text('approve_always_label', 'Always Allow'),
+    button('approve_always_button', 'approve_always_label', {
+      event: {
+        name: 'tool_confirmation',
+        context: {
+          taskId,
+          callId,
+          outcome: 'proceed_always_tool',
+        },
+      },
+    }),
+
+    // Reject button
+    text('reject_label', 'Reject'),
+    button('reject_button', 'reject_label', {
+      event: {
+        name: 'tool_confirmation',
+        context: {
+          taskId,
+          callId,
+          outcome: 'cancel',
+        },
+      },
+    }),
+  ];
+}
+
+/**
+ * Creates an A2UI surface update for tool execution status.
+ */
+export function updateToolCallStatus(
+  taskId: string,
+  callId: string,
+  status: string,
+  output?: string,
+): Part {
+  const surfaceId = `tool_approval_${taskId}_${callId}`;
+
+  logger.info(
+    `[A2UI] Updating tool status surface: ${surfaceId} status: ${status}`,
+  );
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId,
+        path: '/tool/status',
+        value: status,
+      },
+    },
+  ];
+
+  // If tool completed, update the UI to show result
+  if (['success', 'error', 'cancelled'].includes(status)) {
+    messages.push({
+      version: A2UI_VERSION,
+      updateComponents: {
+        surfaceId,
+        components: [
+          // Replace action row with status indicator
+          row('action_row', ['status_icon', 'status_text'], {
+            align: 'center',
+          }),
+          icon(
+            'status_icon',
+            status === 'success'
+              ? 'check_circle'
+              : status === 'error'
+                ? 'error'
+                : 'cancel',
+          ),
+          text(
+            'status_text',
+            status === 'success'
+              ? 'Tool executed successfully'
+              : status === 'error'
+                ? 'Tool execution failed'
+                : 'Tool execution cancelled',
+          ),
+        ],
+      },
+    });
+
+    if (output) {
+      messages.push({
+        version: A2UI_VERSION,
+        updateDataModel: {
+          surfaceId,
+          path: '/tool/output',
+          value: output,
+        },
+      });
+    }
+  }
+
+  return createA2UIPart(messages);
+}
+
+/**
+ * Creates an A2UI text content surface for agent messages.
+ */
+export function createTextContentPart(
+  taskId: string,
+  content: string,
+  surfaceId?: string,
+): Part {
+  const sid = surfaceId || `agent_text_${taskId}`;
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId: sid,
+        path: '/content/text',
+        value: content,
+      },
+    },
+  ];
+
+  return createA2UIPart(messages);
+}
+
+/**
+ * Creates the initial agent response surface.
+ */
+export function createAgentResponseSurface(taskId: string): Part {
+  const surfaceId = `agent_response_${taskId}`;
+
+  logger.info(`[A2UI] Creating agent response surface: ${surfaceId}`);
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      createSurface: {
+        surfaceId,
+        catalogId: STANDARD_CATALOG_ID,
+        theme: {
+          primaryColor: '#1a73e8',
+          agentDisplayName: 'Gemini CLI Agent',
+        },
+      },
+    },
+    {
+      version: A2UI_VERSION,
+      updateComponents: {
+        surfaceId,
+        components: [
+          card('root', 'response_column'),
+          column('response_column', ['response_text', 'status_text'], {
+            align: 'stretch',
+          }),
+          text('response_text', { path: '/response/text' }),
+          text(
+            'status_text',
+            { path: '/response/status' },
+            {
+              variant: 'caption',
+            },
+          ),
+        ],
+      },
+    },
+    {
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId,
+        value: {
+          response: {
+            text: '',
+            status: 'Working...',
+          },
+        },
+      },
+    },
+  ];
+
+  return createA2UIPart(messages);
+}
+
+/**
+ * Updates the agent response surface with new text content.
+ */
+export function updateAgentResponseText(
+  taskId: string,
+  content: string,
+  status?: string,
+): Part {
+  const surfaceId = `agent_response_${taskId}`;
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId,
+        path: '/response/text',
+        value: content,
+      },
+    },
+  ];
+
+  if (status) {
+    messages.push({
+      version: A2UI_VERSION,
+      updateDataModel: {
+        surfaceId,
+        path: '/response/status',
+        value: status,
+      },
+    });
+  }
+
+  return createA2UIPart(messages);
+}
+
+/**
+ * Creates an A2UI thought surface.
+ */
+export function createThoughtPart(
+  taskId: string,
+  subject: string,
+  description: string,
+): Part {
+  const surfaceId = `thought_${taskId}_${Date.now()}`;
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      createSurface: {
+        surfaceId,
+        catalogId: STANDARD_CATALOG_ID,
+        theme: {
+          primaryColor: '#7c4dff',
+          agentDisplayName: 'Gemini CLI Agent',
+        },
+      },
+    },
+    {
+      version: A2UI_VERSION,
+      updateComponents: {
+        surfaceId,
+        components: [
+          card('root', 'thought_column'),
+          column('thought_column', ['thought_icon_row', 'thought_desc'], {
+            align: 'stretch',
+          }),
+          row('thought_icon_row', ['thought_icon', 'thought_subject'], {
+            align: 'center',
+          }),
+          icon('thought_icon', 'psychology'),
+          text('thought_subject', `*${subject}*`, { variant: 'h4' }),
+          text('thought_desc', description),
+        ],
+      },
+    },
+  ];
+
+  return createA2UIPart(messages);
+}
+
+/**
+ * Deletes a tool approval surface after resolution.
+ */
+export function deleteToolApprovalSurface(
+  taskId: string,
+  callId: string,
+): Part {
+  const surfaceId = `tool_approval_${taskId}_${callId}`;
+
+  logger.info(`[A2UI] Deleting tool approval surface: ${surfaceId}`);
+
+  const messages: A2UIServerMessage[] = [
+    {
+      version: A2UI_VERSION,
+      deleteSurface: {
+        surfaceId,
+      },
+    },
+  ];
+
+  return createA2UIPart(messages);
+}
diff --git a/packages/a2a-server/src/agent/executor.ts b/packages/a2a-server/src/agent/executor.ts
index b0522a945f..9cde587118 100644
--- a/packages/a2a-server/src/agent/executor.ts
+++ b/packages/a2a-server/src/agent/executor.ts
@@ -36,6 +36,10 @@ import { loadExtensions } from '../config/extension.js';
 import { Task } from './task.js';
 import { requestStorage } from '../http/requestStorage.js';
 import { pushTaskStateFailed } from '../utils/executor_utils.js';
+import {
+  A2UI_CLIENT_CAPABILITIES_KEY,
+  A2UI_EXTENSION_URI,
+} from '../a2ui/a2ui-extension.js';
 
 /**
  * Provides a wrapper for Task. Passes data from Task to SDKTask.
@@ -435,6 +439,22 @@ export class CoderAgentExecutor implements AgentExecutor {
 
     const currentTask = wrapper.task;
 
+    // Detect A2UI extension activation from the request
+    // Check if user message metadata contains A2UI client capabilities
+    // or if the extensions header includes the A2UI URI
+    const messageMetadata = userMessage.metadata;
+    const hasA2UICapabilities =
+      messageMetadata?.[A2UI_CLIENT_CAPABILITIES_KEY] != null;
+    // Also check if extension URI is referenced in message extensions
+    const messageExtensions = messageMetadata?.['extensions'];
+    const hasA2UIExtension =
+      Array.isArray(messageExtensions) &&
+      messageExtensions.includes(A2UI_EXTENSION_URI);
+    if (hasA2UICapabilities || hasA2UIExtension) {
+      currentTask.a2uiEnabled = true;
+      logger.info(`[CoderAgentExecutor] A2UI enabled for task ${taskId}`);
+    }
+
     if (['canceled', 'failed', 'completed'].includes(currentTask.taskState)) {
       logger.warn(
         `[CoderAgentExecutor] Attempted to execute task ${taskId} which is already in state ${currentTask.taskState}. Ignoring.`,
@@ -552,6 +572,9 @@ export class CoderAgentExecutor implements AgentExecutor {
       logger.info(
         `[CoderAgentExecutor] Task ${taskId}: Agent turn finished, setting to input-required.`,
       );
+      // Finalize A2UI surfaces before marking complete
+      currentTask.finalizeA2UISurfaces();
+
       const stateChange: StateChange = {
         kind: CoderAgentEvent.StateChangeEvent,
       };
diff --git a/packages/a2a-server/src/agent/task.ts b/packages/a2a-server/src/agent/task.ts
index 890bc85b11..96941131f1 100644
--- a/packages/a2a-server/src/agent/task.ts
+++ b/packages/a2a-server/src/agent/task.ts
@@ -56,6 +56,15 @@ import type {
   Citation,
 } from '../types.js';
 import type { PartUnion, Part as genAiPart } from '@google/genai';
+import {
+  createToolCallApprovalSurface,
+  updateToolCallStatus,
+  createAgentResponseSurface,
+  updateAgentResponseText,
+  createThoughtPart as createA2UIThoughtPart,
+  deleteToolApprovalSurface,
+} from '../a2ui/a2ui-surface-manager.js';
+import { isA2UIPart, extractA2UIActions } from '../a2ui/a2ui-extension.js';
 
 type UnionKeys<T> = T extends T ? keyof T : never;
 
@@ -75,6 +84,11 @@ export class Task {
   promptCount = 0;
   autoExecute: boolean;
 
+  // A2UI support
+  a2uiEnabled = false;
+  private accumulatedText = '';
+  private a2uiResponseSurfaceCreated = false;
+
   // For tool waiting logic
   private pendingToolCalls: Map<string, string> = new Map(); //toolCallId --> status
   private toolCompletionPromise?: Promise<void>;
@@ -391,6 +405,44 @@ export class Task {
             : { kind: CoderAgentEvent.ToolCallUpdateEvent };
         const message = this.toolStatusMessage(tc, this.id, this.contextId);
 
+        // Add A2UI parts for tool call updates if A2UI is enabled
+        if (this.a2uiEnabled) {
+          try {
+            if (tc.status === 'awaiting_approval') {
+              const a2uiPart = createToolCallApprovalSurface(this.id, {
+                callId: tc.request.callId,
+                name: tc.request.name,
+                displayName: tc.tool?.displayName || tc.tool?.name,
+                description: tc.tool?.description,
+                args: tc.request.args as Record<string, unknown> | undefined,
+                kind: tc.tool?.kind,
+              });
+              message.parts.push(a2uiPart);
+              logger.info(
+                `[Task] A2UI: Added tool approval surface for ${tc.request.callId}`,
+              );
+            } else if (['success', 'error', 'cancelled'].includes(tc.status)) {
+              const output =
+                'liveOutput' in tc ? String(tc.liveOutput) : undefined;
+              const a2uiPart = updateToolCallStatus(
+                this.id,
+                tc.request.callId,
+                tc.status,
+                output,
+              );
+              message.parts.push(a2uiPart);
+              logger.info(
+                `[Task] A2UI: Updated tool status for ${tc.request.callId}: ${tc.status}`,
+              );
+            }
+          } catch (a2uiError) {
+            logger.error(
+              '[Task] A2UI: Error generating tool call surface:',
+              a2uiError,
+            );
+          }
+        }
+
         const event = this._createStatusUpdateEvent(
           this.taskState,
           coderAgentMessage,
@@ -954,7 +1006,66 @@ export class Task {
     let anyConfirmationHandled = false;
     let hasContentForLlm = false;
 
+    // Reset A2UI accumulated text for new user turn
+    if (this.a2uiEnabled) {
+      this.accumulatedText = '';
+      this.a2uiResponseSurfaceCreated = false;
+    }
+
     for (const part of userMessage.parts) {
+      // Handle A2UI action messages (e.g., button clicks for tool approval)
+      if (this.a2uiEnabled && isA2UIPart(part)) {
+        const actions = extractA2UIActions(part);
+        for (const action of actions) {
+          if (action.action.name === 'tool_confirmation') {
+            const ctx = action.action.context;
+            // Convert A2UI action to a tool confirmation data part
+            const syntheticPart: Part = {
+              kind: 'data',
+              data: {
+                callId: ctx['callId'],
+                outcome: ctx['outcome'],
+              },
+            } as Part;
+            const handled =
+              await this._handleToolConfirmationPart(syntheticPart);
+            if (handled) {
+              anyConfirmationHandled = true;
+              // Emit a delete surface part for the approval UI
+              try {
+                const deletePart = deleteToolApprovalSurface(
+                  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+                  (ctx['taskId'] as string) || this.id,
+                  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+                  ctx['callId'] as string,
+                );
+                const deleteMessage: Message = {
+                  kind: 'message',
+                  role: 'agent',
+                  parts: [deletePart],
+                  messageId: uuidv4(),
+                  taskId: this.id,
+                  contextId: this.contextId,
+                };
+                const event = this._createStatusUpdateEvent(
+                  this.taskState,
+                  { kind: CoderAgentEvent.ToolCallUpdateEvent },
+                  deleteMessage,
+                  false,
+                );
+                this.eventBus?.publish(event);
+              } catch (a2uiError) {
+                logger.error(
+                  '[Task] A2UI: Error deleting approval surface:',
+                  a2uiError,
+                );
+              }
+            }
+          }
+        }
+        continue;
+      }
+
       const confirmationHandled = await this._handleToolConfirmationPart(part);
       if (confirmationHandled) {
         anyConfirmationHandled = true;
@@ -1020,6 +1131,33 @@ export class Task {
     }
     logger.info('[Task] Sending text content to event bus.');
     const message = this._createTextMessage(content);
+
+    // Add A2UI response surface parts if A2UI is enabled
+    if (this.a2uiEnabled) {
+      try {
+        this.accumulatedText += content;
+        if (!this.a2uiResponseSurfaceCreated) {
+          const surfacePart = createAgentResponseSurface(this.id);
+          message.parts.push(surfacePart);
+          this.a2uiResponseSurfaceCreated = true;
+          logger.info(
+            `[Task] A2UI: Created agent response surface for task ${this.id}`,
+          );
+        }
+        const updatePart = updateAgentResponseText(
+          this.id,
+          this.accumulatedText,
+          'Working...',
+        );
+        message.parts.push(updatePart);
+      } catch (a2uiError) {
+        logger.error(
+          '[Task] A2UI: Error generating text content surface:',
+          a2uiError,
+        );
+      }
+    }
+
     const textContent: TextContent = {
       kind: CoderAgentEvent.TextContentEvent,
     };
@@ -1041,15 +1179,35 @@ export class Task {
       return;
     }
     logger.info('[Task] Sending thought to event bus.');
+    const parts: Part[] = [
+      {
+        kind: 'data',
+        data: content,
+      } as Part,
+    ];
+
+    // Add A2UI thought surface if A2UI is enabled
+    if (this.a2uiEnabled) {
+      try {
+        const a2uiPart = createA2UIThoughtPart(
+          this.id,
+          content.subject || 'Thinking...',
+          content.description || '',
+        );
+        parts.push(a2uiPart);
+        logger.info(`[Task] A2UI: Added thought surface for task ${this.id}`);
+      } catch (a2uiError) {
+        logger.error(
+          '[Task] A2UI: Error generating thought surface:',
+          a2uiError,
+        );
+      }
+    }
+
     const message: Message = {
       kind: 'message',
       role: 'agent',
-      parts: [
-        {
-          kind: 'data',
-          data: content,
-        } as Part,
-      ],
+      parts,
       messageId: uuidv4(),
       taskId: this.id,
       contextId: this.contextId,
@@ -1070,6 +1228,43 @@ export class Task {
     );
   }
 
+  /**
+   * Finalizes A2UI surfaces when the agent turn is complete.
+   * Updates the response surface status to "Done".
+   */
+  finalizeA2UISurfaces(): void {
+    if (!this.a2uiEnabled || !this.a2uiResponseSurfaceCreated) {
+      return;
+    }
+    try {
+      const finalPart = updateAgentResponseText(
+        this.id,
+        this.accumulatedText,
+        'Done',
+      );
+      const message: Message = {
+        kind: 'message',
+        role: 'agent',
+        parts: [finalPart],
+        messageId: uuidv4(),
+        taskId: this.id,
+        contextId: this.contextId,
+      };
+      const event = this._createStatusUpdateEvent(
+        this.taskState,
+        { kind: CoderAgentEvent.TextContentEvent },
+        message,
+        false,
+      );
+      this.eventBus?.publish(event);
+      logger.info(
+        `[Task] A2UI: Finalized response surface for task ${this.id}`,
+      );
+    } catch (a2uiError) {
+      logger.error('[Task] A2UI: Error finalizing surfaces:', a2uiError);
+    }
+  }
+
   _sendCitation(citation: string) {
     if (!citation || citation.trim() === '') {
       return;
diff --git a/packages/a2a-server/src/http/app.ts b/packages/a2a-server/src/http/app.ts
index c061d4e3b3..064a65d418 100644
--- a/packages/a2a-server/src/http/app.ts
+++ b/packages/a2a-server/src/http/app.ts
@@ -28,6 +28,7 @@ import { commandRegistry } from '../commands/command-registry.js';
 import { debugLogger, SimpleExtensionLoader } from '@google/gemini-cli-core';
 import type { Command, CommandArgument } from '../commands/types.js';
 import { GitService } from '@google/gemini-cli-core';
+import { getA2UIAgentExtension } from '../a2ui/a2ui-extension.js';
 
 type CommandResponse = {
   name: string;
@@ -46,11 +47,12 @@ const coderAgentCard: AgentCard = {
     url: 'https://google.com',
   },
   protocolVersion: '0.3.0',
-  version: '0.0.2', // Incremented version
+  version: '0.1.0', // A2UI-enabled version
   capabilities: {
     streaming: true,
-    pushNotifications: false,
+    pushNotifications: true,
     stateTransitionHistory: true,
+    extensions: [getA2UIAgentExtension()],
   },
   securitySchemes: undefined,
   security: undefined,
@@ -330,7 +332,8 @@ export async function main() {
     const expressApp = await createApp();
     const port = Number(process.env['CODER_AGENT_PORT'] || 0);
 
-    const server = expressApp.listen(port, 'localhost', () => {
+    const host = process.env['CODER_AGENT_HOST'] || 'localhost';
+    const server = expressApp.listen(port, host, () => {
       const address = server.address();
       let actualPort;
       if (process.env['CODER_AGENT_PORT']) {