# Serpentine3D > Open-source NURBS surface modeller — a Rhino-style freeform modeller on the OpenCASCADE kernel, with AI-native MCP integration - **Type:** MCP server - **Install:** `agentstack add mcp-chisomobanzi-serpentine3d` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [chisomobanzi](https://agentstack.voostack.com/s/chisomobanzi) - **Installs:** 0 - **Category:** [Integrations](https://agentstack.voostack.com/c/integrations) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [chisomobanzi](https://github.com/chisomobanzi) - **Source:** https://github.com/chisomobanzi/Serpentine3D - **Website:** https://chisomobanzi.github.io/Serpentine3D/ ## Install ```sh agentstack add mcp-chisomobanzi-serpentine3d ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Serpentine3D **An open-source NURBS surface modeller for Linux, Windows & macOS — a Rhino-style freeform workflow with native AI integration.** [Download for Linux](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-x86_64.AppImage) · [Windows](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-Setup-x86_64.exe) · [macOS](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-0.5.2-arm64.dmg) · [Website](https://chisomobanzi.github.io/Serpentine3D/) Serpentine3D (`serp3d`) is a freeform surface modeller in the spirit of Rhinoceros 3D — BREP/NURBS geometry on the OpenCASCADE kernel, not meshes. It is built for set designers, architects, and industrial designers who want a genuine Rhino-style workflow: a command line that prompts for input, layers, object snaps to a construction plane, STEP/OBJ/FBX interchange, and a dark, focused interface. The whole modelling engine also runs headless, so the same geometry you build by hand can be scripted, batch-processed, or driven by an AI. Named for the serpentine stone of Zimbabwean Shona sculpture, and for the S-curve at the heart of NURBS geometry. ## Why - **No open-source freeform NURBS surface modeller exists.** FreeCAD is parametric solid CAD; Blender is mesh-based. Serpentine3D fills the freeform surface-modelling gap — on Linux, Windows and macOS alike. - **First CAD tool with native AI integration.** The bundled MCP server lets Claude (or any MCP client) see your viewport, create geometry, run any command, and manage the scene. - **Headless-first.** The modelling core is fully decoupled from the GUI — script it (`serp3d-batch`), import it as a Python library, or drive it over MCP. Repeatable, configurable, light, CI-friendly. Exact BREP surfaces & solids on OpenCASCADE Zebra & curvature surface analysis ## Install ### Download | Platform | Download | Notes | |---|---|---| | **Linux** | [`Serpentine3D-x86_64.AppImage`](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-x86_64.AppImage) | `chmod +x` and run — nothing to install | | **Windows** | [`Serpentine3D-Setup-x86_64.exe`](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-Setup-x86_64.exe) | Installer (Inno Setup) | | **macOS** (Apple Silicon) | [`Serpentine3D-arm64.dmg`](https://github.com/chisomobanzi/Serpentine3D/releases/latest/download/Serpentine3D-0.5.2-arm64.dmg) | Drag to Applications | Each download bundles the OpenCASCADE kernel and Python runtime — nothing else to install. The GUI needs a GPU with OpenGL 3.3 drivers, which any normal desktop has; GPU-less VMs and remote-desktop sessions that only expose OpenGL 1.1 get a clear message instead of a viewport. Headless use (`serp3d-batch`, the MCP server, file conversion) works anywhere. ### From source Requires Python 3.10+. ```bash git clone https://github.com/chisomobanzi/Serpentine3D && cd Serpentine3D python3 -m venv .venv .venv/bin/pip install -e . .venv/bin/serp3d # launch ``` The OpenCASCADE kernel installs as pip wheels (`cadquery-ocp`) — no conda, no system packages. The same install works on Linux, Windows and macOS; the full test suite (360+ tests) passes on all three. ## The command line Everything works Rhino-style: type a command, answer its prompts. Prompts accept typed coordinates (`10,5,0`, relative `@5,0,0`) or viewport clicks on the construction plane. `Tab` completes command names, `Up`/`Down` recall history, `Enter` on an empty line repeats the last command, `Escape` cancels. As in Rhino, a **right-click in the viewport acts as Enter** — it runs whatever you've typed, commits a value mid-command, or repeats the last command. | | Commands | |---|---| | **Curves** | `line` `polyline` `curve` (interpolated NURBS) `circle` `arc` `ellipse` `rectangle` `helix` `textobject` `blendcrv` `project` `pull` `intersect` | | **Surfaces** | `extrude` `revolve` `loft` `sweep1` `sweep2` `planarsrf` `patch`/`networksrf` `offsetsrf` `unrollsrf` | | **Solids** | `box` `sphere` `cylinder` `cone` `torus` `filletedge` `chamferedge` (both pick edges directly; fillets chain and take `start,end` variable radii) `shell` `cap` `contour` `booleansplit` `pushpull` | | **Deform** | `twist` `taper` `bend` `flow` (curve-to-curve) `extend` `matchcrv` | | **Booleans** | `booleanunion` `booleandifference` `booleanintersection` | | **Transform** | `move` `copy` `rotate` `scale` `scalenu` `mirror` `array` | | **Edit** | `join` `explode` `trim` `split` `offset` `fillet` `rebuild` `pointson`/`pointsoff` (control points, curves *and* surfaces) `delete` `hide` `show` `rename` `undo` `redo` | | **Select** | `selall` `selnone` `selcrv` `selsrf` `selsolid` `sellayer` `selname` `sellast` `invert` `isolate` `unisolate` | | **Organise** | `group`/`ungroup` `lock`/`unlockall` `block` `insert` `blocklist` `count` `bringtofront`/`sendtoback` `bringforward`/`sendbackward` (draw order) | | **Camera** | `camera` (lens mm, cinema sensors, placement, 2.39/1.85 frame guides) `units` `cplane` | | **Array** | `array` (grid) `arraypolar` `arraypath` (along a curve) | | **Analysis** | `distance` `length` `area` `volume` `curvature` `zebra` `curvaturegraph` (combs) `draftanalysis` `printcheck` (3D-print readiness: watertight, thin walls, overhangs, size) | | **View** | `top` `front` `right` `perspective` `4view`/`1view` `zoomextents` `wireframe` `shaded` `ghosted` `rendered` `technical` `grid` `snap` | | **Render** | `material` (Matte/Plastic/Metal/Glass/custom PBR — flows into GLB/USD export) `rendered` | | **Layers** | `layer` (new/current/show/hide/rename/weight/**linetype**) — or use the Layers panel | | **Linetypes** | `linetype` — dashed/dotted/hidden/center/… per object or ByLayer (layers carry a linetype too); dashes render in the viewport *and* in exported layout sheets (PDF/SVG) | | **Meshes** | heavy OBJ/3DM/FBX props stay native meshes (instant display); `meshtobrep` / `breptomesh` convert | | **Files** | `new` `open` `save` `import` `export` (`.serp` is a zip container with thumbnail + metadata) | | **Live** | `recordhistory` — loft/extrude/revolve outputs rebuild when their input curves are edited | Most commands have Rhino-compatible aliases (`l`, `pl`, `c`, `m`, `co`, `mi`, ...). Command options appear as **clickable chips** under the prompt (`Cap=Yes`, `BothSides=No`, `Style=Normal`) and can be typed Rhino-style (`cap=n`) at any moment without losing your place; numeric prompts show a live **gold ghost preview** of the result while you type. `help` (or F1) opens a searchable command reference. Arrow keys nudge the selection along the CPlane (Shift ×10, Ctrl ×0.1). ### Navigation & shortcuts - **Middle mouse** orbit · **Shift+Middle** pan · **Scroll** zoom - **F1–F4** top/front/right/perspective · **Ctrl+E** zoom extents · **F7** grid - **Ctrl+Z / Ctrl+Y** undo/redo · **Ctrl+A** select all · **Delete** delete selection - **Ctrl+S / Ctrl+O / Ctrl+N** save/open/new - Click to select (Shift-click adds, Ctrl-click removes), click empty space to deselect - **Box selection**: drag left-to-right for a *window* (fully enclosed, gold box), right-to-left for a *crossing* (anything touched, white box); Shift adds, Ctrl removes - **Control points**: `pointson` (F10) shows CVs on curves — drag a CV to edit the curve live; `pointsoff` (F11) hides them - **Object snaps** — end, mid, center, quadrant, intersection, perpendicular, and nearest-point, each with a distinct cursor marker. Toggle types on the **osnap bar** under the command line, or in Settings. `gridsnap` snaps picked points to the grid - Launch with a file: `serp3d model.serp` (or any importable format) ## Drafting & documentation Serpentine3D has a full two-space drafting workflow — model in 3D, document in 2D, print to PDF — without leaving the app: - **Layouts** (`layout`): paper-space sheets (A4–A0, Letter, Tabloid or custom) with tabs at the bottom of the viewport: `[Model] [Sheet 1] …` - **Detail views** (`detail`): live windows into the model placed on the sheet — pick two corners, a view direction (top/front/right/…/perspective) and a scale (`1:10`, `1:50`, …). Double-click a detail to *enter* it, then pan (nav-button drag) and zoom (wheel changes the scale); click outside to exit. `detailscale`, `detailmode`, `detaillock`, `detailborder`, `detaildelete` manage the active detail. - **Hidden-line rendering**: each detail can be *technical* (hidden lines removed), *hidden* (dashed hidden lines), *wireframe* or *shaded* — powered by OCCT's HLR engine, isolated in a worker process so degenerate geometry can never crash the app. The same engine drives the model-space `technical` display mode. - **`make2d`**: project the current view (or a selection) into real, editable 2D curves on `Make2D visible` / `Make2D hidden` layers. - **Annotations**: multiline `text`, `leader`, `dim` / `dimradius` / `dimdiameter` / `dimangle`, `hatch` (pick corners or **Mode=Region** to click inside detail linework), `scalebar`, `titleblock`, `sheetindex` and per-sheet `revision` tables. Everything on a sheet is selectable — drag to move, grips resize detail frames, Delete removes, `annotedit` edits — and dimensions picked inside a detail are **associative**: they re-project when the detail pans or rescales. `dimstyle` manages named text/arrow styles. - **`exportpdf`** (Ctrl+P): true vector PDF — linework stays crisp at any zoom; shaded details are embedded as rendered images. Layouts save/load with the `.serp` file. ### The gumball Select anything and a **gumball** appears: drag the arrows to move along an axis, the pads to move in a plane, the circles to rotate (Shift snaps to 15°), the square knobs to scale along an axis (Shift = uniform). Alt-drag moves a copy. Escape cancels a drag. `gumball` toggles it. Ctrl+Shift-click a **face** of a solid and the gumball becomes a push/pull handle along the face normal — drag it, or type a distance, to extrude the face outward or carve it inward; the solid rebuilds live and the handle stays on the moved face for repeated pulls. A **curved face** (a cylinder or cone wall, a sphere) offsets instead — push it to grow or shrink the radius, adjacent faces extending to meet it. Select **several faces** and one handle offsets them all together, each along its own normal — inflate a shape, or grow a slab from both sides at once. Ctrl+Shift-click one or more **edges** and the gumball becomes a fillet handle — drag it outward, or type a radius, to round the edges; every selected edge fillets together at that radius, previewing live. Hold **Alt** while dragging to chamfer instead of fillet. ### Units `units` sets the document units (mm/cm/m/in/**feet-and-inches**) with an optional model rescale. Every prompt then accepts unit input — `3'6"`, `2' 4 1/2"`, `30cm`, `1.5in` — and coordinates support polar entry (`10 *a spiral staircase, 3 m tall, 14 steps, 900 mm radius* > *fillet every edge of the box 2 mm* > *what's the volume of the hull?* It works with the full command set (the same commands you type), can measure and inspect the scene, and can **look at the viewport** — it takes a screenshot, checks its own work, and fixes mistakes before answering. Everything it does streams into the panel as it happens, and everything is undoable. Bring your own Anthropic API key (Settings → Assistant, or the `ANTHROPIC_API_KEY` environment variable — get one at [console.anthropic.com](https://console.anthropic.com)). Usage is billed to your Anthropic account; the assistant never phones home anywhere else, and the key never leaves your machine except to call the API. ## MCP server (AI integration) Prefer driving Serpentine3D from an external agent (Claude Code, Claude Desktop)? The same modelling surface is exposed as MCP tools. Start the app, then register the server with your MCP client: ```bash claude mcp add serpentine3d -- /path/to/.venv/bin/serp3d-mcp ``` Tools: `serp_scene_info`, `serp_screenshot` (returns an image of the viewport), `serp_create_curve`, `serp_create_surface`, `serp_boolean`, `serp_transform`, `serp_select`, `serp_command` (run any command with its interactive inputs), `serp_layers`, `serp_import`, `serp_export`, `serp_measure`, `serp_undo`, `serp_viewport`. The combination of `serp_screenshot` and `serp_command` means an AI assistant can model alongside you: it sees what you see and can operate every tool the command line offers. The bridge is a localhost-only JSON-RPC socket (`~/.serpentine3d/rpc.port`); set `SERP3D_NO_RPC=1` to disable it. ## Architecture ``` serpentine3d/ ├── core/ # kernel layer: geometry builders, tessellation, │ # scene graph, layers, selection, undo history ├── commands/ # generator-based interactive commands (Rhino-style │ # prompt protocol, shared by GUI + MCP) ├── ui/ # Qt: GL viewport, command line, panels, dark theme ├── fileio/ # .serp, STEP, 3DM, OBJ, FBX, STL, DXF, SVG, GLB, USD ├── scripting.py # stable headless Document API (serp3d-batch) ├── mcp_server/ # stdio MCP server -> RPC bridge ├── api.py # programmatic API over a running session └── rpc.py # localhost JSON-RPC bridge ``` Geometry is exact BREP on OpenCASCADE 7.9 (via the `OCP` pybind11 bindings); the viewport tessellates on demand with trim-aware isocurve display. Commands are Python generators that yield typed input requests — the same command code serves typed input, viewport clicks, and MCP calls. ## Plugins Drop a `.py` file into `~/.serpentine3d/plugins/` defining `serpentine3d_plugin(ctx)`, or ship a package with a `serpentine3d.plugins` entry point — plugins register first-class commands (with prompts, osnaps, undo and MCP support for free) and menu items. See `docs/scripting.md`. ## Development ```bash .venv/bin/pip install -e ".[dev]" .venv/bin/pytest # unit tests (geometry, scene, commands, file I/O) ``` ## License MIT ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [chisomobanzi](https://github.com/chisomobanzi) - **Source:** [chisomobanzi/Serpentine3D](https://github.com/chisomobanzi/Serpentine3D) - **License:** MIT - **Homepage:** https://chisomobanzi.github.io/Serpentine3D/ Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-chisomobanzi-serpentine3d - Seller: https://agentstack.voostack.com/s/chisomobanzi - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. 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