KiCAD-MCP-Server/docs/KNOWN_ISSUES.md

Known Issues & Workarounds

Last Updated: 2025-10-26 Version: 2.0.0-alpha.2

This document tracks known issues and provides workarounds where available.

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🐛 Current Issues

1. Component Placement Fails - Library Path Not Found

Status: 🔴 BLOCKING - Cannot place components

Symptoms:

Error: Could not find footprint library

Root Cause: MCP server doesn't have access to KiCAD's footprint library paths

Workaround: None currently - feature not usable

Fix Plan: Week 2 priority

• Detect KiCAD library paths from environment
• Add configuration for custom library paths
• Integrate JLCPCB/Digikey part databases

Tracking: High Priority - Required for any real PCB design

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2. Routing Operations Untested with KiCAD 9.0

Status: 🟡 UNKNOWN - May have API compatibility issues

Affected Commands:

• route_trace
• add_via
• add_copper_pour
• route_differential_pair

Symptoms: May fail with API type mismatch errors (like set_board_size did)

Workaround: None - needs testing and fixes

Fix Plan: Week 2 priority

• Test each routing command with KiCAD 9.0
• Fix API compatibility issues
• Add comprehensive routing examples

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3. get_board_info KiCAD 9.0 API Issue

Status: 🟡 KNOWN - Non-critical

Symptoms:

AttributeError: 'BOARD' object has no attribute 'LT_USER'

Root Cause: KiCAD 9.0 changed layer enumeration constants

Workaround: Use get_project_info instead for basic project details

Fix Plan: Week 2

• Update to use KiCAD 9.0 layer constants
• Add backward compatibility for KiCAD 8.x

Impact: Low - informational command only

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4. UI Auto-Reload Requires Manual Confirmation

Status: 🟢 BY DESIGN - Will be fixed by IPC

Symptoms:

• MCP makes changes
• KiCAD detects file change
• User must click "Reload" button to see changes

Current Workflow:

1. Claude makes change via MCP
2. KiCAD shows: "File has been modified. Reload? [Yes] [No]"
3. User clicks "Yes"
4. Changes appear in UI

Why: SWIG-based backend requires file I/O, can't push changes to running UI

Fix Plan: Weeks 2-3 - IPC Backend Migration

• Connect to KiCAD via IPC socket
• Make changes directly in running instance
• No file reload needed - instant visual feedback

Workaround: This is the current expected behavior - just click reload!

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🔧 Recently Fixed

✅ KiCAD Process Detection (Fixed 2025-10-26)

Was: check_kicad_ui detected MCP server's own processes Now: Properly filters to only detect actual KiCAD binaries

✅ set_board_size KiCAD 9.0 (Fixed 2025-10-26)

Was: Failed with BOX2I_SetSize type error Now: Works with KiCAD 9.0 API, backward compatible with 8.x

✅ add_board_text KiCAD 9.0 (Fixed 2025-10-26)

Was: Failed with EDA_ANGLE type error Now: Works with KiCAD 9.0 API, backward compatible with 8.x

✅ Missing add_board_text Command (Fixed 2025-10-26)

Was: Command not found error Now: Properly mapped to Python handler

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📋 Reporting New Issues

If you encounter an issue not listed here:

1. Check MCP logs: ~/.kicad-mcp/logs/kicad_interface.log
2. Check KiCAD version: pcbnew --version (must be 9.0+)
3. Try the operation in KiCAD directly - is it a KiCAD issue?
4. Open GitHub issue with:
   • Error message
   • Log excerpt
   • Steps to reproduce
   • KiCAD version
   • OS and version

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🎯 Priority Matrix

Issue	Priority	Impact	Effort	Status
Component Library Integration	🔴 Critical	High	Medium	Week 2
Routing KiCAD 9.0 Compatibility	🟡 High	High	Low	Week 2
IPC Backend (Real-time UI)	🟡 High	Medium	High	Week 2-3
get_board_info Fix	🟢 Low	Low	Low	Week 2

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💡 General Workarounds

Server Won't Start

# Check Python can import pcbnew
python3 -c "import pcbnew; print(pcbnew.GetBuildVersion())"

# Check paths
python3 python/utils/platform_helper.py

Commands Fail After Server Restart

# Board reference is lost on restart
# Always run open_project after server restart

KiCAD UI Doesn't Show Changes

# File → Revert (or click reload prompt)
# Or: Close and reopen file in KiCAD

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Need Help?

• Check docs/VISUAL_FEEDBACK.md for workflow tips
• Check docs/UI_AUTO_LAUNCH.md for UI setup
• Open an issue on GitHub