View GDS Lens on the VS Code Marketplace | View GDS Lens on Open VSX

A VS Code extension that adds a custom editor for .gds (GDSII) and .oas / .oasis (OASIS) layout files: open one and it's parsed and rendered in a WebGL2 canvas, with support for loading a KLayout .lyp file to drive layer colors.

GDS Lens rendering a GDSII layout

Features

Parses and renders GDSII and OASIS layouts directly in a VS Code webview.
Optional KLayout .lyp file loading for custom layer colors.
Handles SREF/AREF (including array references), rotation, mirroring, and magnification via gdstk's flattening.
Per-layer visibility toggles, an infill (fill pattern) toggle, and a text toggle for the layout's own labels.
Measure tool: click two points to read out the distance between them.
Marker databases: load DRC/LVS violation markers (KLayout .lyrdb or Calibre DRC ASCII results) as a highlight overlay with a browsable category/item panel that zooms to each violation.
Follows your VS Code theme: light or dark, canvas and panel both, switching live when you change themes.
A background reference grid, pitched at a round distance that follows the zoom.

Usage

Open any .gds, .oas, or .oasis file in VS Code and it opens in the GDS Lens viewer (the format is read from the file's own header, so a layout named with an unexpected extension still loads correctly):

Pan / zoom — drag to pan, scroll to zoom.
Layers — toggle individual layer visibility from the panel.
Infill — toggle the hatched layer fill on or off from the panel.
Text — toggle the layout's text labels (GDSII/OASIS TEXT elements) on or off. Labels draw at a constant on-screen size in their layer's color and respect that layer's visibility checkbox. Off by default, since a dense design's labels can bury the geometry underneath them.
Grid — toggle the background reference grid. Its spacing is a round nm/µm/mm step chosen from the zoom, so it agrees with the scale bar; on by default.
Reset View — refit the layout to the window from the panel.
Mode: Pan | Measure — pick the mouse's mode in the panel (or press M to switch). In Measure, click two points to measure the distance between them (total, Δx, and Δy); the cursor turns into a crosshair, and wheel zoom keeps working. Escape returns to Pan and clears the measurement.
Reload on change — when the open layout is rewritten on disk (by a generator script, KLayout, ...) a header offers Reload, which re-reads the file while keeping the camera and per-layer visibility, so the new geometry lands in place. Always reloads from then on without asking; the "GDSLens: Toggle Auto-Reload on Change" command turns that back off.
Load KLayout .lyp File — apply custom layer colors from a .lyp file.
Load Marker File — load a DRC/LVS marker database (KLayout .lyrdb report database or Calibre DRC ASCII results database; the format is detected from the file's content, not its extension). Violations draw as a red overlay above all layers, and a "Markers" panel lists each category (rulecheck) with a visibility toggle and clickable items that zoom the view to the violation — press [ / ] to step through them. Categories start hidden; check the rulechecks you want drawn (clicking an item always shows that marker, even if its category is hidden). The panel also has an overlay opacity slider and a "Hide empty categories" toggle to hide rulechecks with 0 violations. The marker file is remembered per layout file and re-applied when you reopen it; unload it with the ✕ on the panel row.
GDSLens: Toggle Debug Tools — command palette entry that shows/hides the debug panel button, which opens the render stats readout and debug log.
GDSLens: Toggle Auto-Reload on Change — command palette entry that turns automatic reloading on layout changes on or off (the GDS-Lens.autoReload setting).