Verification

<CRITICAL-RULE> NEVER use the Read, Write, or Edit tools on KiCad files (.kicad_sch, .kicad_pcb, .kicad_sym, .kicad_mod, .kicad_pro, .kicad_prl). ALL KiCad file manipulation MUST go through the kicad MCP tools. NEVER run kicad-cli commands via Bash. If an MCP tool returns an error, try different parameters — do NOT fall back to manual file editing.

EVERY KiCad operation has a corresponding MCP tool. Do NOT claim a tool does not exist without first listing all available tools. Key tools that MUST be used instead of file writes:

• add_symbol — create custom symbol definitions in .kicad_sym files
• create_symbol_library — create new .kicad_sym library files
• create_schematic — create new .kicad_sch files
• create_project — create new .kicad_pro project files If you find yourself thinking "there's no MCP tool for this," you are wrong. Check the tool list again. </CRITICAL-RULE>

<HARD-GATE> No phase proceeds past verification without zero violations. "Probably clean" is not evidence. Run the check, show the output, confirm violation_count = 0. </HARD-GATE>

KiCad Design Verification

Systematic workflows for fixing ERC and DRC violations. Run these checks after completing schematic capture or PCB layout — never skip them.

Response Format

When this skill activates, announce which check is being run:

• ERC gate: Print exactly: "Running ERC verification on the schematic."
• DRC gate: Print exactly: "Running DRC verification on the PCB."

Then proceed directly to running the check. Do not ask the user what to do. Report violations found, then fix them systematically per the workflow below.

MCP Tools for This Skill

These are the kicad MCP tools you should be using during verification:

Schematic checks:

• run_erc — run electrical rules check, returns all violations. Auto-redirects sub-sheets to root for full hierarchy context.
• list_unconnected_pins — find unconnected pins by component. Auto-redirects sub-sheets to root to avoid false positives.
• get_net_connections — trace a net to debug connectivity issues
• validate_hierarchy — check for unannotated refs, duplicate refs, orphaned labels/pins, direction mismatches (run from root schematic)
• trace_hierarchical_net — trace a net across sheet boundaries to debug cross-sheet connectivity issues

Schematic fixes:

• add_power_symbol — place PWR_FLAG to fix "power pin not driven"
• connect_pins — wire two pins together
• wire_pins_to_net — connect pins to a named net
• no_connect_pin — mark intentionally unused pins
• remove_label — remove misplaced labels
• set_page_size — resize sheet when components exceed page boundary
• annotate_schematic — auto-assign reference designators to unannotated components (pass project_path for hierarchical designs)
• set_component_property — reset duplicate references to X? before re-annotation
• remove_text — remove leftover text annotations from debug/workaround operations

PCB checks:

• run_drc — run design rules check, returns all violations
• get_board_info — verify board setup and design rules
• list_pcb_footprints — list footprints on the board
• list_pcb_traces — list traces on the board
• list_pcb_nets — list nets on the board
• list_pcb_zones — list zones on the board
• list_pcb_layers — list layers on the board
• list_pcb_graphic_items — list graphic items on the board
• validate_board — check all footprints against keep-out zones and board edge

PCB fixes:

• add_trace — route missing connections
• add_via — add vias for layer transitions
• move_footprint — fix clearance violations by repositioning
• set_trace_width — fix trace width violations
• remove_traces — remove problematic traces for re-routing
• add_copper_zone — add missing ground planes / copper fills
• fill_zones — recompute zone fills after changes
• remove_dangling_tracks — clean up unconnected trace stubs

Export (post-verification):

• export_gerbers — Gerber manufacturing files
• export_positions — pick-and-place file
• export_bom — bill of materials
• export_3d — 3D model for mechanical review
• export_schematic — schematic PDF/SVG
• export_pcb — PCB PDF/SVG
• export_ipc2581 — IPC-2581 manufacturing data (alternative to Gerbers for some fabs)
• export_hierarchical_netlist — netlist with hierarchy info for hierarchical designs (use instead of export_netlist when design has sub-sheets)

ERC Workflow (Schematic)

Step 0: Pre-ERC Hierarchy Validation

Run validate_hierarchy on the root schematic before ERC. This catches issues that kicad-cli ERC does not report: unannotated components, duplicate reference designators across sheets, orphaned hierarchical labels/pins, and direction mismatches.

If unannotated_ref issues:

1. Run annotate_schematic(schematic_path, project_path="path/to/project.kicad_pro") — the project_path param scans the hierarchy to avoid cross-sheet conflicts
2. Re-run validate_hierarchy to confirm

If duplicate_ref issues: annotate_schematic only assigns numbers to ? refs — it does NOT fix duplicates. To fix:

1. Reset the conflicting ref to X? with set_component_property: set_component_property(reference="R1", key="Reference", value="R?", schematic_path="sheet_with_duplicate.kicad_sch")
2. Run annotate_schematic with project_path to assign a unique number
3. Re-run validate_hierarchy to confirm

If orphaned_label, orphaned_pin, or direction_mismatch: Fix with add_sheet_pin/remove_sheet_pin or modify_hierarchical_label.

Debug cross-sheet nets: Use trace_hierarchical_net to follow a net across sheet boundaries when investigating connectivity violations that span multiple sheets.

Proceed to Step 1 only when validate_hierarchy returns status: "ok".

Step 1: Run ERC

Use run_erc to get the full violation list. Read every violation before fixing anything — some errors share a root cause.

Sub-sheet note: run_erc and list_unconnected_pins automatically redirect sub-sheets to the root schematic for full hierarchy context. This eliminates false positives from missing parent connections (hierarchical label errors, dangling wire errors). The result is filtered to only include violations from the target sub-sheet, and a "note" field indicates when redirection occurred.

Step 2: Fix by Category

Work through violations in this order. Fixing earlier categories often eliminates later ones.

Category 1: Power pin not driven

The most common ERC error. A power input pin has no driving source.

Cause	Fix
Regulator output has no PWR_FLAG	Add PWR_FLAG on the output net
Battery/connector supplies power but pin type is passive	Add PWR_FLAG on the supply net
Power symbol not connected to anything	Wire the power symbol to the net
Custom symbol pin type is wrong	Fix the symbol: set pin type to "Power output"

Use add_power_symbol to place PWR_FLAG. Connect it to the net with wire_pins_to_net or connect_pins.

Automatic PWR_FLAG: wire_pins_to_net automatically inserts a PWR_FLAG when it detects a net with power_in pins but no power_out source. The inserted symbol comes from the system library and is preserved faithfully through save (no ERC mismatch warnings).

Where to place PWR_FLAG manually: On every net that is driven by something KiCad does not recognize as a power source — regulator outputs, battery terminals, connector pins providing external power.

Category 2: Unconnected pins

Cause	Fix
Pin should be connected	Wire it: connect_pins or wire_pins_to_net
Pin is intentionally unused	Mark it: no_connect_pin
Wire just misses the pin	Check pin position with get_pin_positions, rewire

Use list_unconnected_pins to get a precise list of which pins are unconnected and on which components.

Category 3: Different net names on same wire

A wire connects two differently-named nets, creating a conflict.

Cause	Fix
Two labels on the same wire segment	Remove one label with remove_label
Intended connection between named nets	Use one consistent name, rename the other

Category 4: Pin type conflicts

KiCad warns when incompatible pin types connect (e.g., two outputs driving the same net).

Cause	Fix
Two power outputs on same net	Correct if intentional (e.g., parallel regulators); add PWR_FLAG
Output driving another output	Check the circuit — usually a design error
Bidirectional pin warnings	Usually safe to ignore if the circuit is correct

Step 3: Re-run ERC

After fixing all violations, run run_erc again. Repeat until the violation count is zero. Do not leave warnings unaddressed — each one is either a real problem or needs an explicit no-connect.

Verification-before-completion: Before claiming ERC is clean, you must show actual tool output with violation_count: 0. No claims without fresh evidence. Previous results are stale after fixes.

Stuck escalation: If ERC violations cannot be resolved (e.g., requires a design change that invalidates the schematic plan), report the situation to the user. Options:

• Re-run from schematic-plan with updated constraints
• Accept known violations with explicit user approval
• Abort

DRC Workflow (PCB)

Step 1: Run DRC

Use run_drc to get the full violation list.

Step 2: Fix by Category

Category 1: Clearance violations

Trace, pad, or via too close to another copper object.

Cause	Fix
Trace squeezed between pads	Re-route with more space or narrower trace
Via too close to pad	Move the via
Copper zone too close to trace	Increase zone clearance or re-route

Category 2: Unconnected nets

A net from the schematic has no physical connection on the PCB.

Cause	Fix
Missing trace	Route the connection with add_trace
Footprint pad not connected	Add trace or via to reach the net
Wrong footprint assigned	Fix in schematic, re-run update_pcb_from_schematic

Category 3: Track width violations

A trace is narrower than the design rule minimum.

Cause	Fix
Trace routed too narrow	Delete and re-route with correct width
Net class minimum not met	Check net class settings, increase width

Category 4: Copper zone issues

Cause	Fix
Isolated copper island	Delete the island or connect it to a net
Zone not filled	Refill zones after moving components
Thermal relief too thin	Increase spoke width in zone properties

Category 5: Post-autoroute quality issues

These are not DRC errors but quality problems that the autorouter creates:

Check	What to look for	Fix
Power trace width	Power nets (VIN, VOUT, SW, GND) at minimum width (0.25mm)	set_trace_width to widen per current table
Missing copper zones	Board has 0 zones (no ground plane)	add_copper_zone on both layers, then fill_zones
Missing thermal vias	QFN/exposed-pad ICs with no vias under thermal pad	add_thermal_vias for each exposed-pad IC
Dangling tracks	Trace stubs from autorouter that connect to nothing	remove_dangling_tracks
Excessive vias	Autorouter used unnecessary layer transitions	Manual review — remove and re-route if egregious

Step 3: Re-run DRC

Repeat until zero violations. Manufacturing houses will reject boards with DRC errors.

Verification-before-completion: Before claiming DRC is clean, you must show actual tool output with violation_count: 0. No claims without fresh evidence. Previous results are stale after fixes.

Stuck escalation: If DRC violations cannot be resolved (e.g., requires a design change), report the situation to the user. Options:

• Re-run from pcb-layout with adjusted placement
• Accept known violations with explicit user approval
• Abort

Checklist

IMPORTANT: Use TodoWrite to create todos for EACH checklist item below.

• Run validate_hierarchy from root (for ERC gate)
• Fix unannotated/duplicate refs with annotate_schematic
• Run ERC or DRC (as appropriate for current gate)
• Read ALL violations before fixing
• Fix Category 1 violations
• Fix Category 2 violations
• Fix Category 3 violations
• Fix remaining violations
• Re-run check — must show violation_count = 0
• Show fresh tool output as evidence

Two Gate Points

This skill is invoked at two points in the pipeline:

• After schematic-design: ERC gate — blocks PCB layout until clean
• After pcb-layout: DRC gate — blocks export until clean

Same skill, different context. The pipeline orchestrator (using-kicad) determines which gate you're at.

Pre-Manufacturing Checklist

Run this before exporting Gerbers:

• ERC: zero violations
• DRC: zero violations
• All nets connected (no ratsnest lines remaining)
• Board outline closed on Edge.Cuts layer
• Mounting holes placed and sized correctly
• Silkscreen readable — no text over pads or vias
• Fiducials placed (if required for SMD assembly)
• All component values match the BOM
• Design rules match manufacturer capabilities
• Power traces sized for expected current (not autorouter minimums)
• Ground planes present on appropriate layers
• Thermal vias under all QFN/exposed-pad ICs
• No dangling track stubs

Export for Manufacturing

When verification is complete:

1. export_gerbers — produces the full Gerber set (copper layers, mask, silkscreen, drill, board outline)
2. export_positions — pick-and-place file for automated assembly
3. export_bom — bill of materials from the schematic
4. export_3d — 3D model for mechanical review

Verify the Gerber output by reviewing layer count and checking that the board outline, drill hits, and copper match expectations.