diff --git a/README.md b/README.md
index cc6b87980..694425dac 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ _A gallery of A2UI rendered cards, showing a variety of UI compositions that A2U
 
 ## ⚠️ Status: Early stage public preview
 
-> **Note:** A2UI is currently in **v0.8 (Public Preview)**. The specification and
+> **Note:** A2UI is currently in **v0.9 (Public Preview)**. The specification and
 > implementations are functional but are still evolving. We are opening the project to
 > foster collaboration, gather feedback, and solicit contributions (e.g., on client renderers).
 > Expect changes.
diff --git a/docs/concepts/overview.md b/docs/concepts/overview.md
index 7fb2d8d8b..32f9c3683 100644
--- a/docs/concepts/overview.md
+++ b/docs/concepts/overview.md
@@ -28,24 +28,33 @@ How components connect to application state using JSON Pointer paths. Covers rea
 
 ## Message Types
 
-=== "v0.8 (Stable)"
+=== "v0.9 (Stable)"
 
-    Version 0.8 uses the following message types:
+    Version 0.10 uses the following message types:
 
     - **`surfaceUpdate`**: Define or update UI components
     - **`dataModelUpdate`**: Update application state
     - **`beginRendering`**: Signal the client to render
     - **`deleteSurface`**: Remove a UI surface
 
-=== "v0.9 (Draft)"
+=== "v0.10 (Draft)"
 
-    Version 0.9 uses the following message types:
+    Version 0.10 uses the following message types:
 
     - **`createSurface`**: Create a new surface and specify its catalog
     - **`updateComponents`**: Add or update UI components in a surface
     - **`updateDataModel`**: Update application state
     - **`deleteSurface`**: Remove a UI surface
 
-    v0.9 separates surface creation from rendering — `createSurface` replaces both `beginRendering` and the implicit surface creation in `surfaceUpdate`. All messages include a `version` field.
+    v0.10 introduces the `actionResponse` message type, enabling robust client-to-server synchronous RPC capabilities.
+
+=== "v0.8 (Legacy)"
+
+    Version 0.8 uses the following message types:
+
+    - **`surfaceUpdate`**: Define or update UI components
+    - **`dataModelUpdate`**: Update application state
+    - **`beginRendering`**: Signal the client to render
+    - **`deleteSurface`**: Remove a UI surface
 
 For complete technical details, see [Message Reference](../reference/messages.md).
diff --git a/docs/guides/a2ui-in-mcp-apps.md b/docs/guides/a2ui-in-mcp-apps.md
index ae3257549..f5da99be2 100644
--- a/docs/guides/a2ui-in-mcp-apps.md
+++ b/docs/guides/a2ui-in-mcp-apps.md
@@ -104,29 +104,27 @@ MCP Apps are typically delivered as a single HTML resource from the MCP Server.
 2.  Use a post-build script (like the [`inline.js`](https://github.com/google/A2UI/blob/main/samples/mcp/a2ui-in-mcpapps/server/apps/src/inline.js) script in the sample) to read the `index.html` and replace external `<script src="...">` and `<link rel="stylesheet" href="...">` tags with inline `<script>` and `<style>` tags containing the actual file contents.
 3.  This produces a self-contained HTML file that can be safely loaded via `srcdoc` in the restricted iframe.
 
-> [!TIP]
-> **Using Vite to inline**
->
-> If your project uses Vite (common for React, Vue, or Lit), you can achieve the same single-file output automatically using plugins like `vite-plugin-singlefile`. This eliminates the need for a custom post-build script by handling the inlining during the build process itself.
->
-> **How to use it:**
->
-> 1. **Install the plugin**:
->    ```bash
->    npm install -D vite-plugin-singlefile
->    ```
-> 2. **Configure Vite**: Add the plugin to your `vite.config.ts` (or `.js`):
->
->    ```typescript
->    import {defineConfig} from 'vite';
->    import {viteSingleFile} from 'vite-plugin-singlefile';
->
->    export default defineConfig({
->      plugins: [viteSingleFile()],
->    });
->    ```
->
->    This will ensure that all JS and CSS assets are inlined into the `index.html` file on build, making it ready to be served by your MCP server as a single resource.
+!!! tip "Using Vite to inline"
+If your project uses Vite (common for React, Vue, or Lit), you can achieve the same single-file output automatically using plugins like `vite-plugin-singlefile`. This eliminates the need for a custom post-build script by handling the inlining during the build process itself.
+
+    **How to use it:**
+
+    1. **Install the plugin**:
+       ```bash
+       npm install -D vite-plugin-singlefile
+       ```
+    2. **Configure Vite**: Add the plugin to your `vite.config.ts` (or `.js`):
+
+       ```typescript
+       import {defineConfig} from 'vite';
+       import {viteSingleFile} from 'vite-plugin-singlefile';
+
+       export default defineConfig({
+         plugins: [viteSingleFile()],
+       });
+       ```
+
+       This will ensure that all JS and CSS assets are inlined into the `index.html` file on build, making it ready to be served by your MCP server as a single resource.
 
 ### Step 2: Leveraging A2UI-over-MCP
 
diff --git a/docs/index.md b/docs/index.md
index 5cbc94b35..824beb985 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -22,10 +22,11 @@ A2UI enables AI agents to generate rich, interactive user interfaces that render
 
 ## Specification Versions
 
-| Version                                | Status      | Description                                                                                                                                               |
-| -------------------------------------- | ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| **[v0.8](specification/v0.8-a2ui.md)** | **Stable**  | Current production release. Surfaces, components, data binding, adjacency list model.                                                                     |
-| **[v0.9](specification/v0.9-a2ui.md)** | **Current** | Adds `createSurface`, client-side functions, custom catalogs, and the extension specification. [Evolution guide →](specification/v0.9-evolution-guide.md) |
+| Version                                  | Status     | Description                                                                                                                                                                           |
+| ---------------------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| **[v0.9](specification/v0.9-a2ui.md)**   | **Stable** | Current production release. Adds `createSurface`, client-side functions, custom catalogs, and the extension specification. [Evolution guide →](specification/v0.9-evolution-guide.md) |
+| **[v0.10](specification/v0.10-a2ui.md)** | **Draft**  | Adds Client-to-Server RPC (actionResponse), custom functions, and dynamic schema features. [Evolution guide →](specification/v0.10-evolution-guide.md)                                |
+| **[v0.8](specification/v0.8-a2ui.md)**   | **Legacy** | Surfaces, components, data binding, adjacency list model.                                                                                                                             |
 
 A2UI is Apache 2.0 licensed,
 created by Google with contributions from CopilotKit and the open source community,
@@ -37,7 +38,7 @@ Instead of text-only responses or risky code execution, A2UI lets agents send **
 
 This repository contains:
 
-- **[A2UI specifications](specification/v0.8-a2ui.md)** (v0.8 stable, v0.9 draft).
+- **[A2UI specifications](specification/v0.9-a2ui.md)** (v0.9 stable, v0.10 draft).
 - **Implementations for [renderers](reference/renderers.md)** (Angular, Flutter, Lit, Markdown, etc.) on the client side.
 - **Transports like [A2A](concepts/transports.md)** which communicate A2UI messages between agents and clients.
 
@@ -125,9 +126,9 @@ This repository contains:
 
   ***
 
-  Dive into the complete technical specs: [v0.8 (stable)](specification/v0.8-a2ui.md) · [v0.9 (draft)](specification/v0.9-a2ui.md)
+  Dive into the complete technical specs: [v0.9 (stable)](specification/v0.9-a2ui.md) · [v0.10 (draft)](specification/v0.10-a2ui.md)
 
-  [:octicons-arrow-right-24: Read the v0.8 spec](specification/v0.8-a2ui.md)
+  [:octicons-arrow-right-24: Read the v0.9 spec](specification/v0.9-a2ui.md)
 
 </div>
 
diff --git a/docs/introduction/what-is-a2ui.md b/docs/introduction/what-is-a2ui.md
index f9b1c571f..c4750fdb4 100644
--- a/docs/introduction/what-is-a2ui.md
+++ b/docs/introduction/what-is-a2ui.md
@@ -40,7 +40,7 @@ A2UI: JSON messages describing UI that:
 
 ### Example
 
-=== "v0.8 (Stable)"
+=== "v0.9 (Stable)"
 
     ```jsonl
     {
@@ -110,14 +110,14 @@ A2UI: JSON messages describing UI that:
 
     ```jsonl
     {
-      "version": "v0.9",
+      "version": "v0.10",
       "createSurface": {
         "surfaceId": "booking",
         "catalogId": "https://a2ui.org/specification/v0_9/basic_catalog.json"
       }
     }
     {
-      "version": "v0.9",
+      "version": "v0.10",
       "updateComponents": {
         "surfaceId": "booking",
         "components": [
@@ -151,7 +151,7 @@ A2UI: JSON messages describing UI that:
       }
     }
     {
-      "version": "v0.9",
+      "version": "v0.10",
       "updateDataModel": {
         "surfaceId": "booking",
         "path": "/booking",
@@ -162,7 +162,7 @@ A2UI: JSON messages describing UI that:
     }
     ```
 
-    Key differences in v0.9: `createSurface` replaces `beginRendering`, components use a flatter structure with `"component": "Text"` instead of nested objects, and all messages include a `version` field.
+    In v0.9 (Stable), `createSurface` replaces `beginRendering`, components use a flatter structure with `"component": "Text"` instead of nested objects, and all messages include a `version` field.
 
 Client renders these messages as native components (Angular, Flutter, React, etc.).
 
diff --git a/docs/quickstart.md b/docs/quickstart.md
index 8d23bdf76..8428b9a8e 100644
--- a/docs/quickstart.md
+++ b/docs/quickstart.md
@@ -131,7 +131,7 @@ In the web app, try these prompts:
 
 Let's peek at what the agent is sending. Here's a simplified example of the JSON messages:
 
-=== "v0.8 (Stable)"
+=== "v0.9 (Stable)"
 
     **Defining the UI:**
 
@@ -162,7 +162,7 @@ Let's peek at what the agent is sending. Here's a simplified example of the JSON
     {"beginRendering": {"surfaceId": "main", "root": "header"}}
     ```
 
-=== "v0.9 (Draft)"
+=== "v0.10 (Draft)"
 
     **Creating the surface:**
 
@@ -189,6 +189,35 @@ Let's peek at what the agent is sending. Here's a simplified example of the JSON
 
     Note: In v0.9, `createSurface` replaces `beginRendering`, components use a flatter format, and the data model uses plain JSON values instead of typed adjacency lists.
 
+=== "v0.10 (Draft)"
+
+    **Creating the surface:**
+
+    ```json
+    {"version": "v0.10", "createSurface": {"surfaceId": "main", "catalogId": "https://a2ui.org/specification/v0_10/basic_catalog.json"}}
+    ```
+
+    **Defining the UI:**
+
+    ```json
+    {"version": "v0.10", "updateComponents": {"surfaceId": "main", "components": [
+      {"id": "header", "component": "Text", "text": "# Book Your Table", "variant": "h1"},
+      {"id": "date-picker", "component": "DateTimeInput", "label": "Select Date", "value": {"path": "/reservation/date"}, "enableDate": true},
+      {"id": "submit-text", "component": "Text", "text": "Confirm Reservation"},
+      {"id": "submit-btn", "component": "Button", "child": "submit-text", "variant": "primary", "action": {"event": {"name": "confirm_booking"}}}
+    ]}}
+    ```
+
+    **Populating data:**
+
+    ```json
+    {"version": "v0.10", "updateDataModel": {"surfaceId": "main", "path": "/reservation", "value": {"date": "2025-12-15", "time": "19:00", "guests": 2}}}
+    ```
+
+    Note: v0.10 continues using the flatter `createSurface` model with support for synchronous client-server `actionResponse` messaging.
+
+=== "v0.8 (Legacy)"
+
 TIP: It's Just JSON
 
 Notice how readable and structured this is? LLMs can generate this easily, and it's safe to transmit and render—no code execution required.
diff --git a/docs/specification/v0.10-a2ui.md b/docs/specification/v0.10-a2ui.md
new file mode 100644
index 000000000..39f0e652f
--- /dev/null
+++ b/docs/specification/v0.10-a2ui.md
@@ -0,0 +1,16 @@
+# A2UI Protocol <span class="version-badge draft">v0.10 — Draft</span>
+
+> Version 0.10 is currently in draft status. For production use, consider [v0.9 (Stable)](v0.9-a2ui.md).
+
+> NOTE: Living Document
+>
+> This specification is automatically included from `specification/v0_10/docs/a2ui_protocol.md`. Any updates to the specification will automatically appear here.
+
+For more information, see the following related documentation:
+
+- [v0.9 Protocol Specification](v0.9-a2ui.md) (Stable).
+- [Evolution Guide: v0.9 → v0.10](v0.10-evolution-guide.md).
+
+---
+
+--8<-- "specification/v0_10/docs/a2ui_protocol.md"
diff --git a/docs/specification/v0.10-evolution-guide.md b/docs/specification/v0.10-evolution-guide.md
new file mode 100644
index 000000000..f5b334634
--- /dev/null
+++ b/docs/specification/v0.10-evolution-guide.md
@@ -0,0 +1,12 @@
+# Evolution Guide <span class="version-badge info">v0.9 → v0.10</span>
+
+> This guide is automatically included from `specification/v0_10/docs/evolution_guide.md`. Any updates will automatically appear here.
+
+For more information, see the following related documentation:
+
+- [A2UI Protocol v0.9](v0.9-a2ui.md) (Stable - what you're migrating from).
+- [A2UI Protocol v0.10](v0.10-a2ui.md) (Draft - what you're migrating to).
+
+---
+
+--8<-- "specification/v0_10/docs/evolution_guide.md"
diff --git a/docs/specification/v0.8-a2a-extension.md b/docs/specification/v0.8-a2a-extension.md
index 14c7bc3cf..f572e2096 100644
--- a/docs/specification/v0.8-a2a-extension.md
+++ b/docs/specification/v0.8-a2a-extension.md
@@ -1,4 +1,4 @@
-# A2UI Extension for A2A Protocol <span class="version-badge stable">v0.8 — Stable</span>
+# A2UI Extension for A2A Protocol <span class="version-badge legacy">v0.8 — Legacy</span>
 
 > NOTE: Living Document
 >
@@ -6,11 +6,11 @@
 
 > NOTE: Version Compatibility
 >
-> This extension specification applies to A2UI v0.8 and the A2A Protocol. For the base A2UI protocol, see [v0.8 Protocol Specification](v0.8-a2ui.md).
+> This extension specification applies to A2UI v0.8 and the A2A Protocol. For the base A2UI protocol, see [v0.8 Protocol Specification](v0.8-a2ui.md) (Legacy).
 
 For more information, see the following related documentation:
 
-- [A2UI Protocol v0.8](v0.8-a2ui.md) (Stable).
+- [A2UI Protocol v0.8](v0.8-a2ui.md) (Legacy).
 - [A2A Protocol Documentation](https://a2a-protocol.org).
 
 ---
diff --git a/docs/specification/v0.8-a2ui.md b/docs/specification/v0.8-a2ui.md
index c9aff9975..4c7535bbf 100644
--- a/docs/specification/v0.8-a2ui.md
+++ b/docs/specification/v0.8-a2ui.md
@@ -1,6 +1,6 @@
-# A2UI Protocol <span class="version-badge stable">v0.8 — Stable</span>
+# A2UI Protocol <span class="version-badge legacy">v0.8 — Legacy</span>
 
-> Version 0.8 is the current stable release, recommended for production use.
+> Version 0.8 is a legacy release, maintained for backward compatibility.
 
 > NOTE: Living Document
 >
@@ -8,9 +8,10 @@
 
 For more information, see the following related documentation:
 
-- [v0.9 Protocol Specification](v0.9-a2ui.md) (Draft).
+- [v0.9 Protocol Specification](v0.9-a2ui.md) (Stable).
+- [v0.10 Protocol Specification](v0.10-a2ui.md) (Draft).
 - [Evolution Guide: v0.8 → v0.9](v0.9-evolution-guide.md).
-- [A2A Extension Specification](v0.8-a2a-extension.md) (for v0.8).
+- [A2A Extension Specification](v0.8-a2a-extension.md) (Legacy).
 
 ---
 
diff --git a/docs/specification/v0.9-a2ui.md b/docs/specification/v0.9-a2ui.md
index be693c5b9..b17f76d1c 100644
--- a/docs/specification/v0.9-a2ui.md
+++ b/docs/specification/v0.9-a2ui.md
@@ -1,6 +1,6 @@
-# A2UI Protocol <span class="version-badge draft">v0.9 — Draft</span>
+# A2UI Protocol <span class="version-badge stable">v0.9 — Stable</span>
 
-> Version 0.9 is currently in draft status. For production use, consider [v0.8 (Stable)](v0.8-a2ui.md).
+> Version 0.9 is the current stable release, recommended for production use.
 
 > NOTE: Living Document
 >
@@ -8,7 +8,8 @@
 
 For more information, see the following related documentation:
 
-- [v0.8 Protocol Specification](v0.8-a2ui.md) (Stable).
+- [v0.8 Protocol Specification](v0.8-a2ui.md) (Legacy).
+- [v0.10 Protocol Specification](v0.10-a2ui.md) (Draft).
 - [Evolution Guide: v0.8 → v0.9](v0.9-evolution-guide.md).
 
 ---
diff --git a/docs/specification/v0.9-evolution-guide.md b/docs/specification/v0.9-evolution-guide.md
index dc3c557cf..48f1ba497 100644
--- a/docs/specification/v0.9-evolution-guide.md
+++ b/docs/specification/v0.9-evolution-guide.md
@@ -4,8 +4,8 @@
 
 For more information, see the following related documentation:
 
-- [A2UI Protocol v0.8](v0.8-a2ui.md) (Stable - what you're migrating from).
-- [A2UI Protocol v0.9](v0.9-a2ui.md) (Draft - what you're migrating to).
+- [A2UI Protocol v0.8](v0.8-a2ui.md) (Legacy - what you're migrating from).
+- [A2UI Protocol v0.9](v0.9-a2ui.md) (Stable - what you're migrating to).
 
 ---
 
diff --git a/mkdocs.yaml b/mkdocs.yaml
index 9d4c5d6fc..b51b57236 100644
--- a/mkdocs.yaml
+++ b/mkdocs.yaml
@@ -56,21 +56,25 @@ nav:
       - Defining Your Own Catalog: guides/defining-your-own-catalog.md
       - Authoring Custom Components: guides/authoring-components.md
       - Theming & Styling: guides/theming.md
-      - A2UI over MCP: guides/a2ui_over_mcp.md
-      - MCP Apps in A2UI: guides/mcp-apps-in-a2ui.md
-      - A2UI in MCP Apps: guides/a2ui-in-mcp-apps.md
+      - A2UI + MCP:
+          - A2UI over MCP: guides/a2ui_over_mcp.md
+          - MCP Apps in A2UI: guides/mcp-apps-in-a2ui.md
+          - A2UI in MCP Apps: guides/a2ui-in-mcp-apps.md
   - Reference:
       - Component Gallery: reference/components.md
       - Message Reference: reference/messages.md
       - Renderers (Clients): reference/renderers.md
       - Agents (Server-side): reference/agents.md
   - Specifications:
-      - v0.8 (Stable):
-          - A2UI Protocol: specification/v0.8-a2ui.md
-          - A2A Extension: specification/v0.8-a2a-extension.md
-      - v0.9 (Draft):
+      - v0.9 (Stable):
           - A2UI Protocol: specification/v0.9-a2ui.md
           - Evolution Guide: specification/v0.9-evolution-guide.md
+      - v0.10 (Draft):
+          - A2UI Protocol: specification/v0.10-a2ui.md
+          - Evolution Guide: specification/v0.10-evolution-guide.md
+      - v0.8 (Legacy):
+          - A2UI Protocol: specification/v0.8-a2ui.md
+          - A2A Extension: specification/v0.8-a2a-extension.md
   - Ecosystem:
       - A2UI in the World: ecosystem/a2ui-in-the-world.md
       - Community Renderers: ecosystem/renderers.md
@@ -202,8 +206,3 @@ plugins:
         "introduction/where-is-it-used.md": "ecosystem/a2ui-in-the-world.md"
         "guides/guide_a2ui_dynamic_mcp.md": "guides/a2ui-in-mcp-apps.md"
         "guides/mcp-apps-in-a2ui-surface.md": "guides/mcp-apps-in-a2ui.md"
-  # - llmstxt:
-  #     full_output: llms-full.txt
-  #     sections:
-  #       "Specification":
-  #         - a2ui_protocol.md