OriginalCircuit.Altium

A high-performance .NET library for reading and writing Altium Designer EDA files without requiring Altium Designer to be installed. It supports schematic libraries, PCB libraries, schematic documents, and PCB documents, and provides cross-platform rendering to raster images and SVG.

This is version 2.0 — a complete rewrite of the original AltiumSharp library with a new async API, source-generated serialization, and cross-platform rendering.

Supported File Types

File Type	Extension	Read	Write	Render
PCB Library	.PcbLib	Yes	Yes	Yes
Schematic Library	.SchLib	Yes	Yes	Yes
Schematic Document	.SchDoc	Yes	Yes	Yes
PCB Document	.PcbDoc	Yes	Yes	Yes

Installation

Install the core library:

dotnet add package OriginalCircuit.Altium

Optional rendering packages:

dotnet add package OriginalCircuit.Altium.Rendering.Raster   # PNG/JPG via SkiaSharp
dotnet add package OriginalCircuit.Altium.Rendering.Svg      # Vector SVG output

Quick Start

Reading a schematic library:

using OriginalCircuit.Altium;

await using var reader = new SchLibReader("MyLibrary.SchLib");
SchLib schLib = await reader.ReadAsync();

foreach (SchComponent component in schLib.Components)
{
    Console.WriteLine($"{component.Name}: {component.Description}");
}

Reading a PCB library:

await using var reader = new PcbLibReader("MyFootprints.PcbLib");
PcbLib pcbLib = await reader.ReadAsync();

foreach (PcbComponent component in pcbLib.Components)
{
    Console.WriteLine($"{component.Name} — {component.Primitives.Count} primitives");
}

Creating a new PCB library:

using OriginalCircuit.Altium;
using OriginalCircuit.Altium.Records;
using OriginalCircuit.Altium.BasicTypes;

var pcbLib = new PcbLib();
var component = new PcbComponent { Name = "R0402" };

component.Primitives.Add(new PcbPad
{
    Location = new CoordPoint(Coord.FromMils(-25), Coord.Zero),
    SizeTop = new CoordPoint(Coord.FromMMs(0.56), Coord.FromMMs(0.62)),
});

pcbLib.Components.Add(component);

await using var writer = new PcbLibWriter("Output.PcbLib");
await writer.WriteAsync(pcbLib);

Rendering

Three rendering packages are available, all built on the abstractions in OriginalCircuit.Altium.Rendering.Core:

• OriginalCircuit.Altium.Rendering.Raster — renders to PNG or JPG using SkiaSharp (cross-platform)
• OriginalCircuit.Altium.Rendering.Svg — renders to SVG using .NET XML APIs (no native dependencies)

See the examples/ directory for complete rendering examples.

Examples

The examples/ directory contains runnable examples:

• CreateFiles — create SchLib and PcbLib files from scratch
• LoadFiles — read files and inspect their contents
• ModifyFiles — read a file, modify components, and write it back
• RenderFiles — render components to PNG and SVG

Run any example with:

dotnet run --project examples/CreateFiles

Credits

This library is a rewrite of the original AltiumSharp project. Original implementation by Tiago Trinidad (@Kronal).

License

MIT — see LICENSE for details.