Arc
NPM · @HUDSONKIT/ARC-MCP
Author, validate, lay out, render, and diff architecture diagrams as code.
Available components
Last scanned (19 hours ago)
Scores higher than 91% of npm servers
Category Developer Tools
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. How we score → Why this is hard to score →
Supply Chain Security100
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- No install/post-install scripts declared.Pass
- No production dependencies, so there is no dependency health to assess. View diagnostics → Pass
Provenance & Transparency97
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to hudsonkit/arc). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 10 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability80
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1500 tokens (~115/item across 13 items; 10 tools + 3 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management37
- Stability observed for 11 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 10 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 11 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Checks we ran (16)
- Malware scan
- Known CVEs
- Install scripts
- Dependency health
- Source repository
- Provenance
- License
- Maintenance
- Security disclosure
- Schema quality
- Stability
- Tool coverage
- Injection markers
- Destructive annotations
- Judged manipulation
- MCP protocol
Does not apply to this package (2)
- Endpoint SecurityScored on hosted endpoints only. A package has no live endpoint of its own for us to probe.
- Transport & ReachabilityScored on hosted endpoints only. A package has no live endpoint of its own for us to probe.
The score does not measure everything. What the score does not measure →
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 5 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.
- 31 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 29 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
- 25 Oct 26 82
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Analysed npm/@hudsonkit/arc-mcp@0.14.1
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | npm |
| Reason | Verified |
| Discovered via | Registry attestation endpoint |
| Source repo | hudsonkit/arc |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/hudsonkit/arc/.github/workflows/npm-publish.yml@refs/heads/main |
| Rekor log index | 3465518472 |
| Predicate type | SLSA build provenance https://slsa.dev/provenance/v1 |
| Subject digest | sha512:eb255db5b42295c11efcfdaef4b83a979bbebb1532da7ec21a790a551e3a992c99f867d27d703f81de6c3dc8728f781ec16cbfa5b31b57a98e510aebf |
Background: How many MCP packages publish verified provenance →
Dependencies 0 packages
| Packages resolved | 0 |
|---|---|
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
auto_layout ~55
Run Arc auto-layout on a diagram. Pass a full diagram or minimal input (nodeData + connectors + connectorStyles).
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | Full ArcDiagramData or AutoDiagramInput (nodeData, connectors, connectorStyles) |
No output schema declared.
No examples provided.
diagram_to_typescript ~53
Convert a valid Arc diagram JSON into a TypeScript module that exports ArcDiagramData.
| Name | Type | Req | Description |
|---|---|---|---|
| diagram | object | yes | Valid ArcDiagramData JSON |
| exportName | string | – | Const name (default: diagram) |
No output schema declared.
No examples provided.
diff_diagram ~109
Structural diff of two Arc diagrams. Returns a DiagramDelta — added/removed/moved/changed nodes, connector adds/removes/changes (keyed by connector id or from→to), connectorStyles and groups deltas, layoutChanged. Feed it to <ArcDiagram data={head} delta={delta} /> for a diff render.
| Name | Type | Req | Description |
|---|---|---|---|
| base | object | yes | Base ArcDiagramData JSON object or JSON string |
| head | object | yes | Head ArcDiagramData JSON object or JSON string |
No output schema declared.
No examples provided.
editor_handoff ~105
Build URLs to open a diagram in the Arc studio. Returns a hash-based editor URL and showcase link.
| Name | Type | Req | Description |
|---|---|---|---|
| baseUrl | string | – | Studio base URL (default: ARC_EDITOR_URL or http://localhost:5188) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| sessionId | string | – | Session id (generated if omitted) |
| view | string | – | Guided view id to start on (data.views[].id) — deep-links the player chapter |
No output schema declared.
No examples provided.
render_animation ~263
Render diagram flows as a GIF or MP4 artifact. Uses deterministic frame captures through Chrome plus ffmpeg; requires an `output` path because video payloads are too large for MCP text.
| Name | Type | Req | Description |
|---|---|---|---|
| backgroundColor | string | – | CSS background color (defaults to the theme canvas) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| duration | number | – | Seconds to render (default: one full flow cycle) |
| format | string | – | Output format; inferred from `output` extension when omitted |
| fps | number | – | Frames per second (default: 12 for GIF, 30 for MP4) |
| includeGrid | boolean | – | Render the diagram grid (default: branded themes on, others off) |
| mode | string | – | Color mode; defaults to the theme default |
| output | string | yes | Destination file path for the GIF or MP4 |
| padding | number | – | Padding around the export bounds in px (default: 20) |
| scale | number | – | Raster scale factor (default: 2, max: 4) |
| theme | string | – | Arc theme id: default, warm, cool, mono, engineering, workbench, tactical, command, spacex, claude, codex, or inherit |
No output schema declared.
No examples provided.
render_ascii ~59
Render an Arc diagram as monospace ASCII/Unicode box art.
| Name | Type | Req | Description |
|---|---|---|---|
| charset | string | – | Character set (default: unicode) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| maxWidth | integer | – | Max output width in characters |
No output schema declared.
No examples provided.
render_html ~331
Render an Arc diagram as a React component snippet, iframe embed, or standalone HTML page.
| Name | Type | Req | Description |
|---|---|---|---|
| backgroundColor | string | – | CSS background color for format=html (defaults to the theme canvas) |
| baseUrl | string | – | Studio base URL for format=iframe (default: ARC_EDITOR_URL or http://localhost:5188) |
| componentName | string | – | Component function name for format=component (default: ArcDiagramExample) |
| dataName | string | – | Diagram const name for format=component (default: diagram) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| format | string | – | Output format: component (TSX), iframe (embed tag), or html (standalone SVG page). Default: html |
| height | – | – | Iframe height in px or CSS percentage |
| includeGrid | boolean | – | Render the diagram grid for format=html (default: branded themes on, others off) |
| interactive | boolean | – | Whether the React component is interactive |
| mode | string | – | Color mode; defaults to the theme default |
| padding | number | – | Padding around the export bounds in px for format=html (default: 20) |
| sessionId | string | – | Session id for format=iframe URLs (generated if omitted) |
| theme | string | – | Arc theme id: default, warm, cool, mono, engineering, workbench, tactical, command, spacex, claude, codex, or inherit |
| title | string | – | HTML document title or iframe title |
| width | – | – | Iframe width in px or CSS percentage |
No output schema declared.
No examples provided.
render_png ~207
Render an Arc diagram as a PNG via an installed Chrome/Chromium binary. Returns MCP image content plus render metadata. Set ARC_CHROME if Chrome is not on PATH.
| Name | Type | Req | Description |
|---|---|---|---|
| backgroundColor | string | – | CSS background color (defaults to the theme canvas) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| flowTime | number | – | Flow route second to freeze into the PNG (default: 0) |
| includeGrid | boolean | – | Render the diagram grid (default: branded themes on, others off) |
| mode | string | – | Color mode; defaults to the theme default |
| padding | number | – | Padding around the export bounds in px (default: 20) |
| scale | number | – | Raster scale factor (default: 2, max: 4) |
| theme | string | – | Arc theme id: default, warm, cool, mono, engineering, workbench, tactical, command, spacex, claude, codex, or inherit |
No output schema declared.
No examples provided.
render_svg ~193
Render an Arc diagram as deterministic SVG markup using the package export path.
| Name | Type | Req | Description |
|---|---|---|---|
| animateFlows | boolean | – | Embed SMIL flow animation in the SVG (default: true; ignored when flowTime is set) |
| backgroundColor | string | – | CSS background color (defaults to the theme canvas) |
| diagram | object | yes | Valid ArcDiagramData JSON |
| flowTime | number | – | Render flow markers at this route second (disables SMIL animation) |
| includeGrid | boolean | – | Render the diagram grid (default: branded themes on, others off) |
| mode | string | – | Color mode; defaults to the theme default |
| padding | number | – | Padding around the export bounds in px (default: 20) |
| theme | string | – | Arc theme id: default, warm, cool, mono, engineering, workbench, tactical, command, spacex, claude, codex, or inherit |
No output schema declared.
No examples provided.
validate_diagram ~81
Validate an ArcDiagramData document. Returns coded diagnostics — consume by `code`, apply one `supportedFixes` entry, re-validate. `ok` is false while any error-severity diagnostic remains.
| Name | Type | Req | Description |
|---|---|---|---|
| diagram | object | yes | Arc diagram JSON object or JSON string |
| severity | string | – | Filter returned diagnostics by severity (default: all) |
No output schema declared.
No examples provided.
How do I install the Arc MCP server?
Arc runs locally as an npm package, launched with npx -y @hudsonkit/arc-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · @hudsonkit/arc-mcp
claude mcp add hudsonkit-arc -- npx -y @hudsonkit/arc-mcp
What is the Arc MCP server?
Arc is an MCP server listed in the public MCP registry as io.github.hudsonkit/arc. Author, validate, lay out, render, and diff architecture diagrams as code. This page covers its npm package (@hudsonkit/arc-mcp).
Is the Arc MCP server safe to use?
Arc scores 87 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 Arc MCP server expose?
Arc exposes 10 tools: validate_diagram, diff_diagram, auto_layout, render_ascii, render_svg, and 5 more. Their descriptions and schemas cost roughly 1,456 tokens of context every time the server is loaded.
Is the Arc MCP server still maintained?
Arc 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 Arc MCP server under?
Arc declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.
What did VerifyMCP test on the Arc MCP server?
VerifyMCP ran 16 checks on Arc, covering Malware scan, Known CVEs, Install scripts, Dependency health and 12 more. Endpoint Security and Transport & Reachability do not apply to an npm package, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.