---
tagName: 11.9.0
name: Neo.mjs v11.9.0 Release Notes
publishedAt: '2025-11-23T12:55:07Z'
isPrerelease: false
isDraft: false
---
# Neo.mjs v11.9.0 Release Notes

**Happy Birthday, Neo.mjs! 🎉**

Today, November 23, 2025, marks exactly **6 years since the General Availability (GA)** of Neo.mjs on November 23, 2019.

We wanted to make this anniversary release special. Six years ago, we reimagined web development with a multi-threaded, worker-first architecture. Today, we are reimagining it again with the **Agent OS**.

This release moves beyond the "Tool Use" era into a future where agents are first-class citizens—autonomous developers capable of executing code, managing their own infrastructure, and understanding complex context. We have solidified this vision with a comprehensive documentation overhaul, a unified "Neo-Native" AI architecture, and foundational features for the next generation of spatial web apps.

## ✨ Highlights

### 📘 Agent OS: The Comprehensive Manual

We have cemented the "Agent OS" vision with a complete suite of documentation. New guides cover everything from the high-level "Agent OS" concept to deep dives into each MCP server.
-   **[Agent OS Introduction](https://github.com/neomjs/neo/blob/dev/learn/guides/mcp/Introduction.md):** The high-level vision and architecture.
-   **[Code Execution Guide](https://github.com/neomjs/neo/blob/dev/learn/guides/mcp/CodeExecution.md):** A definitive guide to the "Thick Client" pattern (`ai/services.mjs`), including a real-world case study on self-healing database schemas.
-   **Real-World Showcase:** While v11.8 introduced the concept, v11.9 delivers the proof. We've added concrete examples like `ai/examples/debug_session_state.mjs` (a "Thick Client" diagnostic tool) and `ai/examples/migrate_timestamps.mjs` (an autonomous migration utility), proving how agents can maintain their own infrastructure.
-   **Server Guides:** Detailed architecture breakdowns for the **[Knowledge Base](https://github.com/neomjs/neo/blob/dev/learn/guides/mcp/KnowledgeBase.md)**, **[Memory Core](https://github.com/neomjs/neo/blob/dev/learn/guides/mcp/MemoryCore.md)**, and **[GitHub Workflow](https://github.com/neomjs/neo/blob/dev/learn/guides/mcp/GitHubWorkflow.md)** servers.
-   **Philosophy:** We've documented the "Why" behind our Context Engineering and "Save-Then-Respond" protocols.

### 🏗 Unified MCP Architecture & The Runner Pattern

We've completely re-architected our AI infrastructure, paying down technical debt by refactoring all three MCP servers (`memory-core`, `knowledge-base`, `github-workflow`) to use a robust **Runner Pattern**.

Instead of monolithic scripts, we now have a clear separation of concerns:
-   **The Runner (`mcp-stdio.mjs`):** A lightweight entry point responsible for CLI argument parsing (`commander`), global config setup, and error trapping. It acts as the "main" function.
-   **The Server (`Server.mjs`):** A pure `Neo.core.Base` class that encapsulates the application logic. It leverages the framework's powerful lifecycle hooks (`initAsync`, `ready`) to orchestrate complex dependency chains (Database -> Auth -> Transport) without race conditions.

This **Neo-Native** approach means our AI backend services now share the same DNA as our frontend components—making them easier to test, extend, and maintain.

### 🪟 Neo.manager.Window: The "God View"

We introduced `Neo.manager.Window`, a new core manager in the App Worker that tracks the exact geometry of all connected browser windows.
-   **Geometry Tracking:** Automatically tracks `screenX`, `screenY`, `width`, and `height` for every window.
-   **Spatial Awareness:** Enables `getWindowAt(x, y)` queries, a prerequisite for cross-window drag-and-drop.
-   **Reactive Updates:** Extends `Neo.manager.Base` for full observability of window state changes.

### 🧠 Memory Core: Parallel Sessions & Eventual Consistency

We have upgraded the Memory Core's synchronization engine to move beyond the single-agent "happy path" and fully support **Parallel Agent Sessions**.
-   **Eventual Consistency:** The system now employs a robust consistency model that can track multiple agents working simultaneously without corrupting the context window.
-   **Drift Detection:** Intelligent logic automatically compares raw memory logs against cached summaries. If a parallel session adds new memories or crashes unexpectedly, the next agent will detect the "drift" and self-heal the summary on startup.
-   **Numeric Timestamps:** We refactored the storage engine to use numeric timestamps (milliseconds), resolving critical compatibility issues with ChromaDB range queries and ensuring precise session discovery.

## 📦 Full Changelog

### Agent OS & Documentation
-   **[Docs] Re-position Neo.mjs as "Agent Operating System" in Schema and Metadata** (Issue #7844)
-   **Epic: Documentation Overhaul for MCP & Agent OS Architecture** (Issue #7848)
-   **Docs: Create Guide for "Introduction to MCP & Agent OS"** (Issue #7849)
-   **Docs: Create Guide for "The Knowledge Base Server"** (Issue #7850)
-   **Docs: Create Guide for "The Memory Core Server"** (Issue #7851)
-   **Docs: Create Guide for "The GitHub Workflow Server"** (Issue #7852)
-   **Docs: Create Guide for "Code Execution with MCP"** (Issue #7853)
-   **Enhance Knowledge Base MCP Server Guide** (Issue #7854)
-   **Enhance Knowledge Base Guide with 'Why' and Use Cases** (Issue #7855)
-   **Polish Knowledge Base Guide: Config Details & Storytelling** (Issue #7856)
-   **Enhance Memory Core MCP Server Documentation** (Issue #7857)
-   **Documentation: Comprehensive Guide for GitHub Workflow MCP Server** (Issue #7858)
-   **Documentation: Enhance "Code Execution with MCP" Guide** (Issue #7859)
-   **Documentation: Update GitHubWorkflow.md to reference Knowledge Base Server** (Issue #7860)
-   **Enhance Code Execution Guide with Real-World Case Study** (Issue #7876)
-   **Update MCP guides code blocks to be readonly** (Issue #7877)
-   **Enhance README.md with links to new MCP guides and Code Execution section** (Issue #7879)

### AI Infrastructure (Refactoring & Enhancements)
-   **Refactor Memory Core MCP Server to use Neo.core.Base class architecture** (Issue #7869)
-   **Refactor Knowledge Base MCP Server to use Neo.core.Base architecture** (Issue #7871)
-   **Refactor GitHub Workflow MCP Server to use Neo.core.Base architecture** (Issue #7872)
-   **Improve Session Summarization to Handle Parallel and Recent Sessions** (Issue #7861)
-   **Add capability to force summarize all sessions** (Issue #7862)
-   **Refactor SessionService for better error handling and config management** (Issue #7864)
-   **Refactor Memory Core to use numeric timestamps for ChromaDB compatibility** (Issue #7865)
-   **Refactor MemoryService to use crypto-based IDs** (Issue #7867)
-   **Implement consistent error handling for Memory Core MCP tools** (Issue #7868)
-   **Standardize version reporting across MCP servers** (Issue #7873)

### Core Framework
-   **Feat: Create Neo.manager.Window for Multi-Window Geometry Tracking** (Issue #7845)
-   **Refactor Neo.manager.Window to extend Neo.manager.Base** (Issue #7875)
-   **Docs: Clarify distinction between Non-Reactive Configs and Class Fields in Neo.core.Base** (Issue #7870)
-   **Remove duplicate contains() method in Rectangle.mjs** (Issue #7874)
-   **Add Markdown and YAML to Highlight.js build configuration** (Issue #7878)

### Bug Fixes
-   **Bug: Prevent SessionService from summarizing the active session** (Issue #7866)

Here is the example of the code execution pattern where Gemini 3 fixed a running MCP server via run-time tool composition scripts:

<img width="906" height="1377" alt="Screenshot 2025-11-22 at 20 34 08" src="https://github.com/user-attachments/assets/aecc6ab1-885a-41bd-b50d-d818bf764f2a" />

<img width="892" height="1125" alt="Screenshot 2025-11-22 at 20 37 32" src="https://github.com/user-attachments/assets/3740a12f-5718-4155-a296-b9230acdc337" />

All changes in 1 commit: https://github.com/neomjs/neo/commit/08ad5e1f2f2598122ec0c083041baa4c7f214af7
