Altium SchDoc Viewer
Open Altium Designer binary .SchDoc / .SchDot files in VS Code without Altium installed. The extension reads the OLE2 FileHeader stream and shows:
- Components — designator, lib reference, value, footprint, description
- Pins — signal names and electrical type
- Nets — heuristic connectivity from wires, junctions, pin hotspots, net labels, and power ports
- Parameters — component parameters (including hidden metadata when present)
- Preview — themed SVG rendering of wires, pins, component bodies, arcs, ellipses, polygons, beziers, rounded rectangles, junctions, net labels and power ports; pan and zoom. Not a pixel-perfect schematic renderer, but close enough to orient yourself on a real board.
- Raw — truncated record payloads for debugging
Install
Source code: github.com/newmatik/altium-schdoc-viewer
Chat from your AI assistant (MCP)
The extension bundles a Model Context Protocol server that lets Claude Code, Cursor, Claude Desktop, Codex CLI, and VS Code GitHub Copilot agent mode query your .SchDoc files in a structured way — list components, trace nets, pull the BOM, inspect parameters, all from the chat panel.
One-click setup
Open the folder that contains your schematics in VS Code / Cursor, then run:
⌘⇧P → Altium: Set up MCP server for AI chat (Cursor / Claude / Copilot)
A multi-select picker lets you check any combination of:
| Client |
Config file it writes |
| Cursor |
.cursor/mcp.json in the current workspace |
| Claude Code |
.mcp.json in the current workspace |
| VS Code (native MCP / Copilot agent mode) |
.vscode/mcp.json in the current workspace |
| Claude Desktop |
~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or the platform equivalent |
The command merges into any existing config — other MCP servers you've registered stay intact.
Enable the server in your client
All four clients register new MCP servers as disabled / untrusted by default. This is a deliberate security behaviour — writing to mcp.json doesn't auto-grant subprocess execution. After running the setup command:
| Client |
Enable step |
| Cursor |
Reload (⌘R) → Settings → MCP → flip the altium-schdoc toggle on. Then open the Agent / Composer chat (⌘I), not the plain Ask panel. |
| Claude Code |
Restart in the workspace. Claude Code will prompt you to approve the server the first time it's needed — accept. |
| VS Code (Copilot agent mode) |
Run Developer: Reload Window → VS Code shows a trust prompt on first tool use — accept. Use Copilot Chat in Agent mode. |
| Claude Desktop |
Quit and relaunch. The plug icon in the chat shows connected servers. |
MCP tools are invoked by the AI agent based on your prompt — they don't appear in the / slash-command menu. A prompt like "summarize AFE-Eval_Schematics_B.SchDoc" will make the agent call schdoc_summary.
Diagnostics
Altium: Test MCP server (health check) — spawns the bundled server, runs the standard initialize + tools/list handshake, shows "MCP server healthy — N tools" on success. Use this to rule out the server itself as the cause before debugging your chat client's trust / enable flow.
Altium: Show MCP server registration snippet — prints the ready-to-paste JSON for clients the setup command doesn't handle natively.
schdoc_summary, schdoc_title, schdoc_components, schdoc_component, schdoc_pins, schdoc_nets, schdoc_net, schdoc_bom, schdoc_netlist, schdoc_search, schdoc_json.
See SKILL.md for details and example prompts. For per-client manual configuration (tokens, paths, troubleshooting), see the "MCP server" section of CLAUDE.md.
Requirements
Visual Studio Code or a compatible editor 1.85+.
Develop
Open this folder as the workspace root, then Run Extension (F5). The launch config runs npm run build first.
npm ci
npm run build # dist/extension.js and dist/webview.js
npm test
npm run watch # optional
Commands
When a .SchDoc / .SchDot is active (or pick a file when prompted):
| Command |
Description |
| Altium: Export BOM as CSV (grouped) |
Grouped by value/footprint with Qty and compressed designator ranges (R1-R4, R7), plus Manufacturer/MPN columns. |
| Altium: Export Netlist (Protel) |
Real Protel format — component sections then net sections. |
| Altium: Export JSON Model |
Versioned JSON snapshot of the full parsed schematic, for downstream tooling or LLM ingestion. |
| Altium: Reveal Raw Records |
Plain-text dump of record payloads. |
Limitations
- Read-only; no
.SchDoc write-back.
- Single schematic file; no
.PrjPcb multi-sheet project view yet.
- Netlist is heuristic — verify important nets in Altium.
- Preview geometry is close to the original but not pixel-perfect; it's meant for orientation, not as an Altium replacement.
Files are OLE2 compound documents; schematic data is in the FileHeader stream as length-prefixed |KEY=value| records. Child ownership uses parentRecordIndex = OwnerIndex + 1 (zero-based), which matches current Altium binary exports we tested.
Local VSIX (for extension development)
To produce a .vsix on your machine (e.g. testing an unpublished build):
npm ci
npm run package
Then in VS Code: Extensions → … → Install from VSIX… and choose the generated altium-schdoc-viewer-*.vsix in this directory.
License
MIT — see LICENSE.
