# pensketch (npm · @pensketch/mcp)
An MCP server for pensketch: check, render and rasterise hand-sketched diagrams.
- Trust score: 83/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-23
## Components
- npm · `@pensketch/mcp`: 83/100 (this document), [markdown](https://verifymcp.io/servers/alpha-nu-pensketch/pensketch-mcp.md), [page](https://verifymcp.io/servers/alpha-nu-pensketch/pensketch-mcp)
## Channel facts
- Registry: `npm`
- Package: `@pensketch/mcp`
- Version: `0.13.0`
- 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 2026-09-23.
- **Supply Chain Security**: 100/100
- No malware found by supply-chain analysis.
- No known CVEs affecting this package version or its production dependencies.
- No install/post-install scripts declared.
- 0 of 8 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 71/100
- Repository check failed: no source repository is declared.
- Cryptographically verified build provenance (signed, bound to alpha-nu/pensketch).
- Clear OSI-approved license (MIT).
- Actively maintained (last published 7 days ago).
- Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 77/100
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
- AI-judged instruction clarity (excellent).
- Context-footprint check failed: tool/resource definitions use about 3762 tokens (~313/item across 12 items; 4 tools + 8 resources), over budget; trim descriptions and params.
- Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 53/100
- Stability observed for 16 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 99/100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).
- 96% of tool parameters carry a description.
- **Tool Safety**: 100/100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
- An AI judge read all 5 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).
## Install
### How do I install the pensketch MCP server?
pensketch runs locally as an npm package, launched with npx -y @pensketch/mcp. 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 alpha-nu-pensketch -- npx -y @pensketch/mcp
```
### Cursor
```json
{
"mcpServers": {
"alpha-nu-pensketch": {
"command": "npx",
"args": [
"-y",
"@pensketch/mcp"
]
}
}
}
```
### VS Code
```json
{
"servers": {
"alpha-nu-pensketch": {
"command": "npx",
"args": [
"-y",
"@pensketch/mcp"
]
}
}
}
```
### Codex
```bash
codex mcp add alpha-nu-pensketch -- npx -y @pensketch/mcp
```
### opencode
```json
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"alpha-nu-pensketch": {
"type": "local",
"command": [
"npx",
"-y",
"@pensketch/mcp"
],
"enabled": true
}
}
}
```
### OpenClaw
```bash
openclaw mcp add alpha-nu-pensketch --command npx --arg -y --arg @pensketch/mcp
```
### Hermes
```yaml
mcp_servers:
alpha-nu-pensketch:
command: "npx"
args: ["-y", "@pensketch/mcp"]
```
### Netclaw
```json
{
"McpServers": {
"alpha-nu-pensketch": {
"Transport": "stdio",
"Command": "npx",
"Arguments": [
"-y",
"@pensketch/mcp"
]
}
}
}
```
### Vellum
```bash
assistant mcp add alpha-nu-pensketch -t stdio -c npx -a -y @pensketch/mcp
```
### Other
```json
{
"mcpServers": {
"alpha-nu-pensketch": {
"command": "npx",
"args": [
"-y",
"@pensketch/mcp"
]
}
}
}
```
## 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.
### 2026-09-21 (score 83, +1)
No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.
### 2026-09-19 (score 82, +1)
No change was recorded against any check on this day. Stability & Change Management went from 37 to 40. That category is still filling its 30-day observation window: 11 days of observed history at the previous scan, 12 at this one. The score rises as the window fills, whether or not the server changes.
### 2026-09-17 (score 81, +1)
No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.
### 2026-09-16 (score 80, +15)
- [security improvement] Malware scan: unverified → pass
### 2026-09-15 (score 65, −14)
- [security regression] Malware scan: pass → unverified
- [functional regression] Schema quality: 256 → 313
- [functional] Package version: 0.10.0 → 0.13.0
- [functional] Package version: 0.10.0 → 0.12.0
### 2026-09-13 (score 79, +27)
- [security improvement] Malware scan: unverified → pass
- [security improvement] Known CVEs: unverified → pass
- [functional improvement] Dependency health: unverified → 1.00
### 2026-09-12 (score 52, −24)
- [security regression] Known CVEs: pass → unverified
- [security regression] Malware scan: pass → unverified
- [security regression] Tool safety: pass → unverified
- [security] Stability: Stability not yet verified: we do not have a sandbox capture of the MCP schema this version of the package serves yet.
- [functional regression] Schema quality: 2567 → 3079
- [functional regression] Dependency health: 1.00 → unverified
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional regression] Schema quality: 100 → unverified
- [functional improvement] Stability: unverified → 0.17
- [functional] Package version: 0.8.0 → 0.10.0
- [functional] Package version: 0.8.0 → 0.9.0
### 2026-09-07 (score 76)
First indexed and scored.
## MCP tools (4)
### `check_diagram` (~999 tokens)
Check a diagram for layout defects
Reports what neither the types nor the schema can see: overlapping boxes, a label a connector will be drawn through, text too wide for its box, a node half out of its lane, a node no edge names, a depth the renderer would refuse. Draws nothing. Every coordinate is yours: pensketch performs no layout and routes no edges. Text is never measured, so a box does not grow to fit its label. It takes extrude and depth, where it refuses hops: hops change no finding - though where a hop breaks the very line a `label-collision` names, the finding stands and the sentence naming that edge does not - and depth changes the geometry every finding measures - an extruded node is measured over the box its slab sweeps, so a slab that crosses the frame or its neighbour is reported here rather than seen in the picture. Pass the pair you will render with, or the findings are for a drawing you are not making. Pass `anchors: true` and the report ends with the numeric points every edge end resolved to - the arithmetic for verifying a layout you cannot look at. `render_diagram` reports these same findings for the drawing it just made, so reach for this one when you want findings without markup, or before spending a `render_png` - stdio transport only; over HTTP there is no raster - on a diagram you have not checked.
Input parameters:
- `anchors` (boolean): Append the resolved end points of every edge to the report, one line each: the two points its drawn line actually begins and ends at - a side fraction walked, an extruded anchor carried onto the silh…
- `depth` (number): How deep a slab is drawn, in px, for every node without a `depth` of its own. Default 12, calibrated on a box; a pill wants about a third of its height, and a diamond reads as a folded corner at ever…
- `diagram` (object, required): A diagram: nodes, edges, braces and notes as plain data. Read the pensketch://schema resource - or call the get_schema tool, the same document - for every field. The whole diagram is validated agains…
- `extrude` (boolean): Draw every node as a slab: its outline redrawn offset up and to the right and joined to it. A node's own `extrude` wins over this either way, so an extruded diagram can flatten one node and a flat on…
- `viewBox` (array): [minX, minY, width, height], the four numbers the makes the file invalid. Deterministic: the same diagram and seed produce the same bytes. Every coordinate is yours: pensketch performs no layout and routes no edges. Text is never measured, so a box does not grow to fit its label. The markup names the handwriting font stack, so a browser draws it in the reader's own hand-drawn face. It is returned, not displayed: many clients render none of it, so save it to a file, embed it in a page, or hand it onward rather than assuming the reader has seen the picture.
Input parameters:
- `animate` (boolean): Return an