{"slug": "build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp", "title": "Build parametric 3D CAD parts from Claude Code with SolidCraft MCP", "summary": "An open-source project called SolidCraft, written in pure Rust, ships a built-in Model Context Protocol server that lets AI agents such as Claude Code build and edit parametric 3D CAD parts on a feature timeline. The project's README reports that 75 of 76 public reference parts match their analytic or FreeCAD-computed volume, area, centre of mass and bounding box, with the single miss tracked as a bug. Because the desktop app, browser app, headless CLI and MCP server run the same command set, parts an agent generates can be reopened and edited by hand, and command lists can be replayed headless to regenerate STEP files in CI.", "body_md": "If you have tried to get an AI agent to make a real, editable 3D part, you have probably hit the same wall: it writes an STL or a pile of OpenSCAD, and the moment you want to change one dimension you start over. A parametric CAD tool with a feature timeline fixes that, and SolidCraft is one that ships with its own MCP server.\n\n[tangency-labs/solidcraft](https://github.com/tangency-labs/solidcraft) is an open-source parametric 3D CAD application written in pure Rust. Per the README you sketch, constrain and build solids on a parametric feature timeline, change a dimension and watch the model rebuild, and run it on desktop, in the browser, or let AI agents model through the built-in MCP server. This post walks through the setup for Claude Code and what to expect.\n\nThe README calls it \"early but usable for simple parts\" and backs that with a number: 75 of 76 public reference parts match their analytic or FreeCAD-computed volume, area, centre of mass and bounding box. The one miss is a tracked bug.\n\nThe feature list is already broad:\n\n`.sc` designs.\nThe important line for agent users is the last one in that list: the desktop app, browser app, headless CLI and MCP server all run the same commands. Whatever the agent does, you can open and edit by hand.\n\nPick the build for your machine from the README:\n\n```\nsudo snap install solidcraft\n```\n\nIf you prefer to build from source with Rust:\n\n```\ncargo run --release -p solidcraft -- --sample      # desktop app with a sample part\ncargo run --release -p solidcraft-cli -- commands  # the command registry\n```\n\n`solidcraft-cli mcp` is a Model Context Protocol server. One line registers it with Claude Code:\n\n```\nclaude mcp add solidcraft -- solidcraft-cli mcp\n```\n\nTwo modes are worth knowing. Run headless, the server keeps its own design session. Started with `--connect`, it drives the running desktop app so you can watch every feature appear on the timeline. For a first session, the connected mode is far easier to trust.\n\nOn older Windows installers the CLI is not on `PATH`. The README says to give the full path instead, which by default is `C:\\Program Files\\SolidCraft\\solidcraft-cli.exe`.\n\nThe README's own demo is a good template for a prompt: a Raspberry Pi 4 case built from an empty design, with a sketch dimensioned from the board's parameters, extrude, fillet and shell, M2.5 standoffs patterned on the 58 by 49 mm hole rectangle, port cut-outs, vent slots and engraved text. Then the case height goes from 24 to 32 mm in Parameters and everything rebuilds.\n\nSo ask for parameters, not just a shape:\n\n```\nCreate a box enclosure 90 x 60 mm with a height parameter of 30 mm,\n2 mm walls (shell), 1 mm fillets on the outer edges, and four M3 standoffs\npatterned on a 70 x 40 mm rectangle. Name every dimension as a parameter.\n```\n\nWhen it is done, change `height` in the Parameters panel yourself. If the model rebuilds cleanly, the agent built it the right way. Export STEP for a machinist or STL or 3MF for a printer.\n\nA SolidCraft script is a JSON list of the same commands the UI runs. You can run one headless and write a file:\n\n```\ncargo run --release -p solidcraft-cli -- run examples/bracket.json --out bracket.step\n```\n\nThis is handy once the agent has produced a part you like: keep the command list in the repo and regenerate the STEP in CI instead of trusting a binary file.\n\nThe builds we track on the [SolidCraft page](https://dedupedai.com/use-cases/tangency-labs-solidcraft/?utm_source=devto&utm_medium=article&utm_campaign=howto_solidcraft) show where it fits:\n\nIf you want text-to-CAD as a skill set for agents rather than a full CAD app, [text-to-cad](https://dedupedai.com/use-cases/earthtojake-text-to-cad/?utm_source=devto&utm_medium=article&utm_campaign=howto_solidcraft) generates 3D CAD models from text and runs related manufacturing and drawing workflows locally. For organic shapes, scenes and renders instead of engineering parts, [MCP for Blender](https://dedupedai.com/use-cases/ahujasid-mcp-for-blender/?utm_source=devto&utm_medium=article&utm_campaign=howto_solidcraft) connects Blender to an LLM the same way.\n\nSource repo: [tangency-labs/solidcraft](https://github.com/tangency-labs/solidcraft). License: MIT or Apache-2.0.\n\nWant the setup commands for 50 AI repos people actually ship with? Get the free AI Repos That Actually Ship pack: [https://dedupedai.com/ship-pack/?utm_source=devto&utm_medium=article&utm_campaign=shippack](https://dedupedai.com/ship-pack/?utm_source=devto&utm_medium=article&utm_campaign=shippack)", "url": "https://wpnews.pro/news/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp", "canonical_source": "https://dev.to/dedupedai/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp-2754", "published_at": "2026-11-04 04:08:53+00:00", "updated_at": "2026-11-04 04:22:23.609305+00:00", "lang": "en", "topics": ["ai-agents", "agent-protocols", "ai-tools", "developer-tools"], "entities": ["SolidCraft", "Tangency Labs", "Claude Code", "Model Context Protocol", "FreeCAD", "Rust"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp", "markdown": "https://wpnews.pro/news/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp.md", "text": "https://wpnews.pro/news/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp.txt", "jsonld": "https://wpnews.pro/news/build-parametric-3d-cad-parts-from-claude-code-with-solidcraft-mcp.jsonld"}}