fix: Phase 2 - DRC API fix and JLCPCB documentation restructure (#33, #34, #43)

Phase 2 medium-priority fixes addressing three issues:

Issue #33 - DRC violations API broken in KiCAD 9.0:
- Reimplemented get_drc_violations() to use run_drc() internally
- run_drc uses kicad-cli which is stable across KiCAD versions
- Maintains backward compatibility while fixing GetDRCMarkers() issue
- Added documentation to KNOWN_ISSUES.md
- Returns violations in original format by parsing kicad-cli JSON output

Issue #34 - JLCPCB API documentation misleading:
- Restructured README and JLCPCB_USAGE_GUIDE.md
- Now leads with JLCSearch public API (no authentication required)
- Moved official JLCPCB API to "Advanced" section with clear requirements
- Clarified that official API requires enterprise account + order history
- Makes it easier for new users to get started

Issue #43 - JLCPCB part count documentation inaccurate:
- Updated all "100k+" references to "2.5M+" (accurate catalog size)
- Updated download time estimates to 40-60 minutes
- Updated expected database size to 1-2 GB
- Clarified 100-part pagination limit in JLCSearch API

Documentation changes:
- README.md: Updated JLCPCB integration section
- docs/JLCPCB_USAGE_GUIDE.md: Complete restructure with 3 approaches
- docs/KNOWN_ISSUES.md: Added DRC fix documentation

All changes improve user experience and documentation accuracy.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

README.md

@@ -11,7 +11,7 @@ The [Model Context Protocol](https://modelcontextprotocol.io/) is an open standa
 - 64 fully-documented tools with JSON Schema validation
 - Smart tool discovery with router pattern (reduces AI context by 70%)
 - 8 dynamic resources exposing project state
-- JLCPCB parts integration with 100k+ component catalog and local library search
+- JLCPCB parts integration with 2.5M+ component catalog and local library search
 - Full MCP 2025-06-18 protocol compliance
 - Cross-platform support (Linux, Windows, macOS)
 - Real-time KiCAD UI integration via IPC API (experimental)
@@ -129,7 +129,7 @@ Complete integration with JLCPCB's parts catalog, providing two complementary ap
 
 **Dual-Mode Architecture:**
 1. **Local Symbol Libraries** - Search JLCPCB libraries installed via KiCAD Plugin and Content Manager (contributed by [@l3wi](https://github.com/l3wi))
-2. **JLCPCB API Integration** - Access the complete 100k+ parts catalog with real-time pricing and stock data
+2. **JLCPCB API Integration** - Access the complete 2.5M+ parts catalog with real-time pricing and stock data
 
 **Key Features:**
 - Real-time pricing with quantity breaks (1+, 10+, 100+, 1000+)
@@ -457,7 +457,22 @@ Claude Code automatically detects MCP servers in the current directory. No addit
 
 The JLCPCB integration provides two modes that can be used independently or together:
 
-**Mode 1: Local Symbol Libraries (No Setup Required)**
+**Mode 1: JLCSearch Public API (Recommended - No Setup Required)**
+
+The easiest way to access JLCPCB's parts catalog:
+- No API credentials needed
+- No JLCPCB account required
+- Access to 2.5M+ parts with pricing and stock data
+- Download time: 40-60 minutes for full catalog (100-part batches due to API limit)
+
+To download the database:
+```
+Ask Claude: "Download the JLCPCB parts database"
+```
+
+This creates a local SQLite database at `data/jlcpcb_parts.db` (~1-2 GB for full catalog).
+
+**Mode 2: Local Symbol Libraries (No Setup Required)**
 
 Install JLCPCB libraries via KiCAD's Plugin and Content Manager:
 1. Open KiCAD
@@ -466,14 +481,15 @@ Install JLCPCB libraries via KiCAD's Plugin and Content Manager:
 4. Install libraries like `JLCPCB-KiCAD-Library` or `EDA_MCP`
 5. Use `search_symbols` to find components with pre-configured footprints and LCSC IDs
 
-**Mode 2: JLCPCB API (Complete Catalog Access)**
+**Mode 3: Official JLCPCB API (Advanced - Requires Enterprise Account)**
 
-For access to the full 100k+ parts catalog with pricing:
+For users with JLCPCB enterprise accounts and order history:
 
 1. **Get API Credentials**
    - Log in to [JLCPCB](https://jlcpcb.com/)
-   - Navigate to Account > API Management
+   - Navigate to Account > API Management (requires enterprise approval)
    - Create API Key and save your `appKey` and `appSecret`
+   - Note: This requires prior order history and enterprise account approval
 
 2. **Configure Environment Variables**
 
@@ -489,12 +505,6 @@ For access to the full 100k+ parts catalog with pricing:
    JLCPCB_API_SECRET=your_app_secret_here
    ```
 
-3. **Download Parts Database (One-time setup, takes 5-10 minutes)**
-   ```
-   Ask Claude: "Download the JLCPCB parts database"
-   ```
-   This creates a local SQLite database at `data/jlcpcb_parts.db` with ~100k parts.
-
 See [JLCPCB Usage Guide](docs/JLCPCB_USAGE_GUIDE.md) for detailed documentation.
 
 ## Usage Examples

docs/JLCPCB_USAGE_GUIDE.md

@@ -1,11 +1,12 @@
 # JLCPCB Integration Guide
 
-The KiCAD MCP Server provides **two complementary approaches** for working with JLCPCB parts:
+The KiCAD MCP Server provides **three complementary approaches** for working with JLCPCB parts:
 
-1. **Local Symbol Libraries** - Search JLCPCB libraries installed via KiCad PCM _(contributed by [@l3wi](https://github.com/l3wi) in [PR #25](https://github.com/mixelpixx/KiCAD-MCP-Server/pull/25))_
+1. **JLCSearch Public API** - No authentication required, 2.5M+ parts with pricing (Recommended)
-2. **JLCPCB API Integration** - Access the complete 100k+ parts catalog with real-time pricing
+2. **Local Symbol Libraries** - Search JLCPCB libraries installed via KiCad PCM _(contributed by [@l3wi](https://github.com/l3wi) in [PR #25](https://github.com/mixelpixx/KiCAD-MCP-Server/pull/25))_
+3. **Official JLCPCB API** - Requires enterprise account (Advanced)
 
-Both approaches can be used together to give you maximum flexibility.
+All approaches can be used together to give you maximum flexibility.
 
 ## Credits
 
@@ -14,7 +15,46 @@ Both approaches can be used together to give you maximum flexibility.
 
 ---
 
-## Approach 1: Local Symbol Libraries (Recommended for Getting Started)
+## Approach 1: JLCSearch Public API (Recommended)
+
+### What It Does
+- Access to 2.5M+ JLCPCB parts with pricing and stock data
+- **No authentication required** - works immediately
+- **No JLCPCB account needed**
+- Real-time pricing with quantity breaks
+- Basic vs Extended library type identification
+- Local SQLite database for fast offline searching
+- Note: Download takes 40-60 minutes due to API pagination (100 parts per request)
+
+### Setup
+
+No setup required! Just download the database:
+
+```
+download_jlcpcb_database({ force: false })
+```
+
+This downloads ~2.5M parts from JLCSearch API and creates a local SQLite database (`data/jlcpcb_parts.db`).
+
+**Expected Output:**
+```
+Downloading JLCPCB parts database...
+Downloaded 100 parts...
+Downloaded 200 parts...
+... (continues for 40-60 minutes)
+Downloaded 2,500,000 parts...
+
+Total parts: 2,500,000+
+Database size: ~1-2 GB
+```
+
+### Usage Examples
+
+See "Approach 2" usage examples below - the API is the same.
+
+---
+
+## Approach 2: Local Symbol Libraries (Good for Offline Use)
 
 ### What It Does
 - Searches symbol libraries you've installed via KiCad's Plugin and Content Manager (PCM)
@@ -94,10 +134,10 @@ Class: Extended
 
 ---
 
-## Approach 2: JLCPCB API Integration (For Complete Catalog Access)
+## Approach 3: Official JLCPCB API (Advanced - Enterprise Accounts Only)
 
 ### What It Does
-- Downloads the **complete JLCPCB parts catalog** (~100k+ parts)
+- Downloads from the **official JLCPCB API** (requires enterprise account)
 - Provides **real-time pricing and stock information**
 - Automatic **Basic vs Extended** library type identification (Basic = free assembly)
 - Smart suggestions for cheaper/in-stock alternatives

docs/KNOWN_ISSUES.md

@@ -101,6 +101,12 @@ Schematic operations use the kicad-skip library which has some limitations with
 
 ## Recently Fixed
 
+### DRC Violations API KiCAD 9.0 (Fixed 2026-02-26)
+
+**Was:** `get_drc_violations` failed with `AttributeError: 'BOARD' object has no attribute 'GetDRCMarkers'`
+**Now:** Reimplemented to use `run_drc()` internally which calls kicad-cli
+**Impact:** Maintains backward compatibility while using stable kicad-cli interface
+
 ### Component Library Integration (Fixed 2025-11-01)
 
 **Was:** Could not find footprint libraries

python/commands/design_rules.py

@@ -385,7 +385,15 @@ class DesignRuleCommands:
         return None
 
     def get_drc_violations(self, params: Dict[str, Any]) -> Dict[str, Any]:
-        """Get list of DRC violations"""
+        """
+        Get list of DRC violations
+
+        Note: This command internally uses run_drc() which calls kicad-cli.
+        The old BOARD.GetDRCMarkers() API was removed in KiCAD 9.0.
+        This implementation provides backward compatibility by parsing kicad-cli output.
+        """
+        import json
+
         try:
             if not self.board:
                 return {
@@ -396,27 +404,37 @@ class DesignRuleCommands:
 
             severity = params.get("severity", "all")
 
-            # Get DRC markers
+            # Run DRC using kicad-cli (this saves violations to JSON file)
-            violations = []
+            drc_result = self.run_drc({})
-            for marker in self.board.GetDRCMarkers():
+
-                violation = {
+            if not drc_result.get("success"):
-                    "type": marker.GetErrorCode(),
+                return drc_result  # Return the error from run_drc
-                    "severity": "error",  # KiCAD DRC markers are always errors
+
-                    "message": marker.GetDescription(),
+            # Read violations from the saved JSON file
-                    "location": {
+            violations_file = drc_result.get("violationsFile")
-                        "x": marker.GetPos().x / 1000000,
+            if not violations_file or not os.path.exists(violations_file):
-                        "y": marker.GetPos().y / 1000000,
+                return {
-                        "unit": "mm"
+                    "success": False,
-                    }
+                    "message": "Violations file not found",
+                    "errorDetails": "run_drc did not create violations file"
                 }
 
+            # Load violations from file
+            with open(violations_file, 'r', encoding='utf-8') as f:
+                data = json.load(f)
+
+            all_violations = data.get("violations", [])
+
             # Filter by severity if specified
-                if severity == "all" or severity == violation["severity"]:
+            if severity != "all":
-                    violations.append(violation)
+                filtered_violations = [v for v in all_violations if v.get("severity") == severity]
+            else:
+                filtered_violations = all_violations
 
             return {
                 "success": True,
-                "violations": violations
+                "violations": filtered_violations,
+                "violationsFile": violations_file  # Include file path for reference
             }
 
         except Exception as e: