Add Current Implementation section to docs (#484)

* add-architecture

* replace-svg-with-mermaid

Author: Darshan808

docs/source/conf.py

@@ -24,7 +24,7 @@
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
 
-extensions = ["myst_parser", "sphinx.ext.autodoc"]
+extensions = ["myst_parser", "sphinx.ext.autodoc", "sphinxcontrib.mermaid"]
 
 templates_path = ["_templates"]
 exclude_patterns = ["ts/**"]

docs/source/developer/architecture.md

@@ -1,8 +1,47 @@
 # Code Architecture
 
-## Current implementation
+## Current Implementation
 
-COMING...
+Jupyter Collaboration consists of several Python packages and frontend extensions:
+
+- **jupyter_server_ydoc**:
+  A Jupyter Server extension providing core collaborative models. It manages YDocument data structures tied to notebook files and exposes WebSocket endpoints for real-time updates. It integrates CRDTs into Jupyter’s file management and kernel system.
+
+- **jupyter_collaboration**:
+  A meta-package that bundles the backend (`jupyter_server_ydoc`) and frontend (JupyterLab and Notebook 7 UI extensions). It connects the collaborative frontend UX (status badges, shared cursors, etc.) with the backend.
+
+### Key dependencies:
+
+- **pycrdt-websocket**:
+  WebSocket provider library used by the collaboration layer. It runs an async WebSocket server that synchronizes pycrdt documents by managing CRDT updates between clients and the shared server YDoc.
+
+- **pycrdt-store**:
+  Persistence layer for CRDT documents. Uses an SQLite-backed store (`.jupyter_ystore.db`) by default to checkpoint document history. Enables autosave and document state recovery after restarts or offline periods.
+
+<div align="center">
+
+```{mermaid}
+  graph TD
+    subgraph "Frontend Clients"
+      JL["JupyterLab Client"]
+      NB["Notebook Client"]
+    end
+
+    subgraph "Jupyter Server"
+      COLLAB["Collaboration Layer"]
+      WS["WebSocket Provider (pycrdt-websocket)"]
+      YDOC["Shared YDoc"]
+      STORE["Persistent Store (pycrdt-store)"]
+    end
+
+    JL -->|WebSocket| COLLAB
+    NB -->|WebSocket| COLLAB
+    COLLAB --> WS
+    WS --> YDOC
+    YDOC --> STORE
+```
+
+</div>
 
 ## Early attempts
 

pyproject.toml

@@ -33,7 +33,8 @@ docs = [
     "jupyterlab>=4.4.0",
     "sphinx",
     "myst-parser",
-    "pydata-sphinx-theme"
+    "pydata-sphinx-theme",
+    "sphinxcontrib-mermaid"
 ]
 
 [tool.ruff]