> ## Documentation Index
> Fetch the complete documentation index at: https://docs.buildwithtrace.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Schematics

> The schematic editor is where you define the electrical connections of your circuit.

## Editor Overview

The schematic editor provides:

* **Canvas** — Infinite drawing area for your circuit
* **Symbol browser** — Search and place components
* **Properties panel** — Edit component values and attributes
* **Chat panel** — AI assistance for schematic tasks

## Placing Components

Use the symbol browser or press `A` to add components. Search by name, description, or manufacturer part number. Trace includes thousands of built-in symbols from KiCad's standard libraries.

### Symbol Search

When you or the AI search for a component, Trace uses **vector similarity** to find matches by meaning, not just exact name. Searching for "voltage regulator 3.3V" returns relevant LDOs and linear regulators even if the symbol name doesn't contain those exact words.

The search covers the full KiCad symbol library and runs server-side, so results are comprehensive regardless of which libraries you have installed locally.

### Placeholder Symbols

If the AI places a component from search results but the exact library symbol isn't available locally, Trace generates a **placeholder symbol** with the correct pin names, pin numbers, and pin count. This keeps your schematic electrically valid while you assign the final library symbol. Placeholder symbols appear as rectangles with labeled pin stubs.

## Drawing Wires

Press `W` to start drawing wires. Click to place waypoints and double-click or press `Escape` to finish. Wires automatically connect to component pins when placed nearby.

## Hierarchical Sheets

For complex designs, split your schematic across multiple sheets:

* **Hierarchical sheets** — Nested sub-circuits with defined interfaces
* **Sheet pins** — Connect signals between sheets
* **Global labels** — Share signals across all sheets
* **AI sheet navigation** — Ask the AI to switch between sheets or navigate your hierarchy. The AI uses `get_hierarchy` to understand your sheet structure and `switch_sheet` to navigate, reading and editing across sheets with full multi-sheet context.
* **Sheet numbering** — Automatic sheet number assignment across your hierarchy
* **Custom sheet fields** — Add custom fields to sheets via the Properties panel for project-specific metadata (revision, author, approval status, etc.)
* **Auto-increment directive labels** — When placing repeated directive labels, the field values auto-increment for faster annotation

## Annotation

Annotate components to assign unique reference designators (R1, C1, U1, etc.). Use **Tools → Annotate Schematic** or let Trace auto-annotate. The AI can also annotate your schematic automatically during design tasks.

## Electrical Rules Check

Run ERC to find common errors:

* Unconnected pins
* Conflicting pin types (e.g., two outputs connected)
* Missing power connections
* Duplicate reference designators
* **Local labels with no local pin connections** — Labels that exist on a sheet but don't connect to any pin on that sheet (new in Trace 1.3)

Access via **Inspect → Electrical Rules Checker** or `Ctrl+Shift+E`.

### ERC Walkthrough

A typical ERC workflow:

1. Open the Electrical Rules Checker (`Ctrl+Shift+E`)
2. Click **Run ERC** to analyze your schematic
3. Review the violations list — each entry shows the error type, location, and affected components
4. Click a violation to jump to it in the schematic
5. Fix the issue (add a power flag, connect a dangling wire, resolve a pin conflict)
6. Re-run ERC to verify the fix
7. Repeat until no violations remain

The AI can also run ERC for you and explain each violation in plain language. Ask "run ERC and explain the errors" in the chat.

## BOM Generation

Generate a bill of materials from your schematic:

* **Component list** — All components with reference designators, values, footprints, and manufacturer part numbers
* **Supplier links** — Direct links to distributor pages for each component
* **Pricing** — Aggregated pricing at your target quantity
* **Variant-aware** — Components excluded by the active [design variant](/concepts/design-variants) are omitted from the BOM
* **Rule area exclusions** — Components in rule areas marked "exclude from BOM" are omitted

The AI can generate a BOM on request and presents it as an interactive [BOM Preview](/concepts/intelligent-tools#bom-preview--approval) in the chat for your review.

## AI Symbol Creation

The AI can create new schematic symbols from scratch. Describe a component — "Create a symbol for the TPS563200 buck converter with VIN, VOUT, EN, FB, GND, and BOOT pins" — and the AI generates the symbol with correct pin names, numbers, electrical types, and groupings. The symbol is added to your project's custom library.