# Ottogeo — CAD MCP Server (npm · cad-mcp-server)

Measure STEP CAD files with your AI assistant: walls, clearances, draft, and revision diffs.

- Trust score: 80/100 (high trust)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- npm · `cad-mcp-server`: 80/100 (this document), [markdown](https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server.md), [page](https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server)

## Channel facts

- Registry: `npm`
- Package: `cad-mcp-server`
- Version: `0.10.1`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Supply Chain Security**: 99/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 4 of 16 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to ottonic/cad-mcp-server).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 5 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 70/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 2059 tokens (~343/item across 6 items; 5 tools + 1 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the Ottogeo — CAD MCP Server server?

Ottogeo — CAD MCP Server runs locally as an npm package, launched with npx -y cad-mcp-server. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add ottonic-cad-mcp-server -- npx -y cad-mcp-server
```

### Cursor

```json
{
  "mcpServers": {
    "ottonic-cad-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "cad-mcp-server"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "ottonic-cad-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "cad-mcp-server"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add ottonic-cad-mcp-server -- npx -y cad-mcp-server
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "ottonic-cad-mcp-server": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "cad-mcp-server"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add ottonic-cad-mcp-server --command npx --arg -y --arg cad-mcp-server
```

### Hermes

```yaml
mcp_servers:
  ottonic-cad-mcp-server:
    command: "npx"
    args: ["-y", "cad-mcp-server"]
```

### Netclaw

```json
{
  "McpServers": {
    "ottonic-cad-mcp-server": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "cad-mcp-server"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add ottonic-cad-mcp-server -t stdio -c npx -a -y cad-mcp-server
```

### Other

```json
{
  "mcpServers": {
    "ottonic-cad-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "cad-mcp-server"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-01 (score 80, +25)

- [security improvement] Malware scan: unverified → pass
- [security improvement] Known CVEs: unverified → pass
- [functional improvement] Dependency health: unverified → 0.90

### 2026-10-31 (score 55)

First indexed and scored.

## MCP tools (5)

### `inspect` (~146 tokens)

Inspect Model Overview

Inspect a local STEP artifact by filesystem path or file: URI. Returns its content revision with dimensions, counts, and B-rep validity. Call this first; use the returned artifact reference for entity searches and measurements. Lengths are in the declared unit, which is labelled on every result. Bounding boxes are conservative envelopes, and volume is null when the file has no solid material. Use include to request only size, counts, and/or health sections.

Input parameters:

- `include` (array): Sections to return. Omit for all three; ask for fewer to save context on a large assembly.
- `uri` (string, required): STEP file to read, as a file: URI or an absolute filesystem path.

Output parameters:

- `artifact` (object)
- `coordinate_frame` (object)
- `health` (object)
- `size` (object)
- `structure` (object)

### `find_entities` (~462 tokens)

Find Model Entities

Find faces, edges, vertices, or solid bodies in the revision-bound artifact returned by inspect, optionally scoped to an assembly component_name. Use this before measure, because every measurement names entity IDs rather than coordinates, and follow pagination until has_more is false whenever a count or a minimum matters. Faces support surface_type, area, and radius filters (e.g. { surface_type: "cylinder", min_radius: 2 }); edges support curve_type, length, and radius; vertices return coordinates and bodies return volume. IDs are producer- and revision-scoped: they are valid only for this server and only for the artifact revision that returned them, so never reuse them after the file changes or in another tool. Occurrence IDs distinguish repeated component instances. distance takes sources/targets; every other measure kind takes entity_ids, and cad://help lists the required fields for each kind.

Input parameters:

- `artifact` (object, required): Revision-bound STEP reference from inspect (uri + sha256 revision). The revision must still match the file on disk.
- `component_name` (string): Optional component scope from inspect.structure.component_occurrences; use the base name for all repeated instances or the full name#instance ID for one occurrence.
- `curve_type` (string): Edges only: keep edges of this curve type.
- `entity_ids` (array): Optional explicit ids to return; each must match entity_type (e.g. ["face:3"]).
- `entity_type` (string, required): Entity category to search.
- `limit` (integer): Maximum entities to return in this page (default 50).
- `max_area` (number): Faces only: maximum face area in mm².
- `max_length` (number): Edges only: maximum edge length in mm.
- `max_radius` (number): Faces/edges only: maximum radius in mm.
- `min_area` (number): Faces only: minimum face area in mm².
- `min_length` (number): Edges only: minimum edge length in mm.
- `min_radius` (number): Faces/edges only: minimum radius in mm.
- `offset` (integer): Entities to skip; follow pagination.has_more to page.
- `surface_type` (string): Faces only: keep faces of this surface type.

Output parameters:

- `artifact` (object)
- `bounds_method` (string)
- `coordinate_frame` (object)
- `entities` (array)
- `entity_id_scheme` (object)
- `pagination` (object)
- `query` (object)
- `unit_note` (string)
- `units` (object)

### `measure` (~733 tokens)

Measure Geometry

Measure distance, wall thickness, draft, rays/ray grids, point geometry, planar sections, or edge continuity. Use the artifact reference and entity IDs from the same find_entities result. Lengths are in the declared unit, which is labelled on every result. Ray grids report their grid size and can be refined with max_rays up to 20000. Fetch the cad://help resource for the required fields of each kind. Returns geometric measurements only, not engineering acceptance or design recommendations.

Input parameters:

- `artifact` (object, required): Revision-bound STEP reference from inspect: { uri, revision, format, units }. Rejected if the file changed since inspect.
- `bidirectional` (boolean): ray and ray_grid: also shoot from the origin in the opposite direction.
- `checks` (array): point_analysis: one or more of contains_body, classify_face, closest_face_point, surface_curvature, edge_projection.
- `detail` (string): Per-sample detail to return: "stats" (default), "samples", or "hits".
- `direction` (array): ray and ray_grid: ray direction as an explicit [x, y, z] vector. Mutually exclusive with direction_mode.
- `direction_mode` (string): ray and ray_grid: "axis" shoots along the entity axis, "normal" along the entity normal (faces only). Mutually exclusive with direction.
- `entity_ids` (array): Every kind except distance: the entities to measure. Faces for thickness, draft, ray and ray_grid; edges for continuity; faces or bodies for section and point_analysis. Up to 100 IDs.
- `kind` (string, required): Measurement to perform. Each kind takes a different argument set; see the field notes here and the per-kind requirements in cad://help.
- `max_distance` (number): ray, ray_grid and thickness: ignore hits beyond this distance in the STEP artifact’s declared length units.
- `max_rays` (integer): ray_grid and thickness: maximum ray casts, 1 to 20000. Default 4000. Raising it allows a finer grid at proportionally higher cost.
- `origin` (array): ray and ray_grid: explicit ray origin [x, y, z]. Mutually exclusive with origin_mode.
- `origin_mode` (string): ray and ray_grid: place the origin at the entity extent instead of passing origin: extent_min, extent_center (default), or extent_max.
- `plane_normal` (array): section: cutting-plane normal.
- `plane_origin` (array): section: a point on the cutting plane.
- `points` (array): point_analysis: points to test, in model coordinates (mm), up to 100.
- `pull_direction` (array): draft only: mould pull direction as an explicit [x, y, z] vector. Mutually exclusive with pull_direction_mode.
- `pull_direction_mode` (string): draft only: "axis" or "normal" shortcut for the pull direction (faces only). Mutually exclusive with pull_direction.
- `sources` (array): distance only: entities to measure from (face:N, edge:N, body:N, or a component-scoped form).
- `spacing` (number): ray_grid: grid pitch in the STEP artifact’s declared length units, at most 1000.
- `summary` (string): distance only: "all" returns every pair, "minimum" (default) returns the closest pair only.
- `targets` (array): distance only: entities to measure to.
- `tolerance` (number): continuity and point checks: geometric tolerance in millimetres.

Output parameters:

- `artifact` (object)
- `coordinate_frame` (object)
- `entity_id_scheme` (object)
- `kind` (string)
- `subjects` (array)
- `units` (object)

### `describe_pmi` (~498 tokens)

Describe Model PMI and GD&T

Report the dimensions, geometric tolerances, and datums that a STEP artifact declares, as data: nominal, deviations, and tolerance form for each dimension; value, zone shape, material requirement, and datum references for each geometric tolerance; and the entity IDs each annotation applies to. `characteristics` checks each dimensional callout against the faces it controls, and reports satisfied or violated where that is arithmetic — a diameter read from the cylindrical faces the callout names — and unresolved with a reason everywhere else, so a callout that was not checked cannot be mistaken for one that was. Check value_resolved before comparing anything yourself. It is false when the magnitude could not be read and is reported as 0.0, which is what a genuine zero callout also reports; a location dimension defining a tolerance frame has no value of its own. A basic dimension comes back not-applicable: it defines a tolerance frame and states no limit of its own. An angle or a location callout comes back unresolved with needs-frame, because the angle between two faces and a location dimension direction both depend on the frame the callout is stated in. A datum reference carries the entity IDs of the shapes its datum is attached to. Without them a tolerance naming that datum cannot be evaluated, so report the datum as unlocated rather than treating the tolerance as met. `unlocated_datums` names those references for you; a tolerance that carries it is not checkable, and saying which datum is missing is the useful answer.Counts report both datum references and distinct datums, because a frame names its references one by one and the same datum appears once per frame. Values are in the declared unit, the same unit this server uses for measurements. Read pmi_kind before describing what a file does or does not declare: `semantic` means the callouts are readable data; `graphical-only` means the file does show requirements, drawn rather than encoded, so say they must come fr…

Input parameters:

- `include` (array): Sections to include: dimensions, tolerances, datums. Default: all three. Example: ["tolerances"].
- `uri` (string, required): STEP file to read, as a file: URI or an absolute filesystem path.

Output parameters:

- `artifact` (object)
- `characteristics` (array)
- `coordinate_frame` (object)
- `counts` (object)
- `datums` (array)
- `dimensions` (array)
- `geometric_tolerances` (array)
- `pmi_kind` (string)
- `unit_note` (string)
- `units` (object)
- `warnings` (array)

### `diff` (~141 tokens)

Compare Step Versions

Compare baseline and candidate STEP artifacts, as filesystem paths or file: URIs. Returns both content revisions, geometry deltas in the baseline declared unit, declared PMI counts (dimensions, geometric tolerances, datums, and how many tolerance values could not be read), and parsed document facts: schema, product names/count, assembly flag, authoring system, and organization. The PMI counts show whether a revision added or dropped callouts; they compare how many callouts exist, not whether any is met. These are file-level facts; they do not explain design intent.

Input parameters:

- `baseline` (object, required): Original STEP artifact.
- `candidate` (object, required): Modified STEP artifact.

Output parameters:

- `deltas` (object)
- `exchange` (object)
- `inputs` (array)
- `pmi` (object)
- `providers` (object)
- `unit_note` (string)
- `units` (object)

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server#diagnostics

## Score history

- 2026-11-05: 80
- 2026-11-04: 80
- 2026-11-03: 80
- 2026-11-02: 80
- 2026-11-01: 80
- 2026-10-31: 55

## Common questions

### What is the Ottogeo — CAD MCP Server server?

Ottogeo — CAD MCP Server is listed in the public MCP registry as io.github.ottonic/cad-mcp-server. Measure STEP CAD files with your AI assistant: walls, clearances, draft, and revision diffs. This page covers its npm package (cad-mcp-server).

### Is the Ottogeo — CAD MCP Server server safe to use?

Ottogeo — CAD MCP Server scores 80 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 5 November 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Ottogeo — CAD MCP Server server expose?

Ottogeo — CAD MCP Server exposes 5 tools: inspect, find_entities, measure, describe_pmi, diff. Their descriptions and schemas cost roughly 1,980 tokens of context every time the server is loaded.

### Is the Ottogeo — CAD MCP Server server still maintained?

Ottogeo — CAD MCP Server is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the Ottogeo — CAD MCP Server server under?

Ottogeo — CAD MCP Server declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/cad-mcp-server
- Socket report: https://socket.dev/npm/package/cad-mcp-server
- Repository: https://github.com/ottonic/cad-mcp-server
- Changelog RSS feed: https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server.xml
- Changelog JSON feed: https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server.json
- HTML version of this page: https://verifymcp.io/servers/ottonic-cad-mcp-server/cad-mcp-server