# ArcSync (npm · arcsync-mcp)

Architecture graphs from Terraform, CDK, CloudFormation, Pulumi and ARM, for coding agents

- Trust score: 82/100 (high trust)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- npm · `arcsync-mcp`: 82/100 (this document), [markdown](https://verifymcp.io/servers/vanlandinghamlabs-arcsync-mcp/arcsync-mcp.md), [page](https://verifymcp.io/servers/vanlandinghamlabs-arcsync-mcp/arcsync-mcp)

## Channel facts

- Registry: `npm`
- Package: `arcsync-mcp`
- Version: `0.3.5`
- 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**: 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.
  - No production dependencies, so there is no dependency health to assess.
- **Provenance & Transparency**: 97/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to VanLandinghamLabs/arcsync-mcp).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 0 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 74/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1434 tokens (~130/item across 11 items; 11 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 13/100
  - Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 95/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 85% 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 11 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 12 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the ArcSync MCP server?

ArcSync runs locally as an npm package, launched with npx -y arcsync-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 vanlandinghamlabs-arcsync-mcp -- npx -y arcsync-mcp
```

### Cursor

```json
{
  "mcpServers": {
    "vanlandinghamlabs-arcsync-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "arcsync-mcp"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "vanlandinghamlabs-arcsync-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "arcsync-mcp"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add vanlandinghamlabs-arcsync-mcp -- npx -y arcsync-mcp
```

### opencode

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

### OpenClaw

```bash
openclaw mcp add vanlandinghamlabs-arcsync-mcp --command npx --arg -y --arg arcsync-mcp
```

### Hermes

```yaml
mcp_servers:
  vanlandinghamlabs-arcsync-mcp:
    command: "npx"
    args: ["-y", "arcsync-mcp"]
```

### Netclaw

```json
{
  "McpServers": {
    "vanlandinghamlabs-arcsync-mcp": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "arcsync-mcp"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add vanlandinghamlabs-arcsync-mcp -t stdio -c npx -a -y arcsync-mcp
```

### Other

```json
{
  "mcpServers": {
    "vanlandinghamlabs-arcsync-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "arcsync-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.

### 2026-11-05 (score 82, +44)

- [security improvement] Injection markers: unverified → pass
- [security improvement] Known CVEs: unverified → pass
- [functional improvement] Tool coverage: unverified → 100
- [functional improvement] Stability: unverified → 0.13
- [functional improvement] MCP protocol: unverified → pass
- [functional improvement] Dependency health: unverified → pass
- [functional] Package version: 0.3.4 → 0.3.5

### 2026-11-04 (score 38, −43)

- [security regression] Known CVEs: pass → unverified
- [security regression] Stability: 0.07 → unverified
- [security regression] Tool safety: pass → unverified
- [functional regression] Dependency health: pass → unverified
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional] Package version: 0.3.2 → 0.3.4
- [functional] Package version: 0.3.2 → 0.3.3

### 2026-11-03 (score 81, 0)

- [functional] Package version: 0.3.1 → 0.3.2

### 2026-11-02 (score 81, +43)

- [security improvement] Injection markers: unverified → pass
- [security improvement] Known CVEs: unverified → pass
- [security] First check of Judged manipulation: pass
- [functional improvement] Tool coverage: unverified → 100
- [functional improvement] MCP protocol: unverified → pass
- [functional improvement] Stability: unverified → 0.03
- [functional improvement] Dependency health: unverified → pass
- [functional] First check of Schema quality: fail
- [functional] First check of Schema quality: excellent
- [functional] First check of Destructive annotations: pass
- [functional] First check of Schema quality: fail
- [functional] First check of Tool coverage: 85

### 2026-11-01 (score 38)

First indexed and scored.

## MCP tools (11)

### `list_diagrams` (~102 tokens)

List ArcSync diagrams

List the architecture diagrams in the caller's ArcSync workspace (one per repository, branch and IaC path), newest first. Use it to find the graphId for a repository before calling get_diagram, describe_resource or get_delta. Optional `query` filters by repository URL, owner, repo name, branch, path or project type.

Input parameters:

- `limit` (integer): Maximum rows (default 25).
- `query` (string): Case-insensitive substring filter.

### `get_diagram` (~116 tokens)

Get an ArcSync diagram

Fetch one architecture diagram ArcSync parsed from infrastructure-as-code. `format: "mermaid"` (default) returns a Mermaid flowchart to show or embed; `format: "json"` returns the resources and relationships as lists to reason over. Both include a link to the interactive canvas. Prefer this to inferring architecture from source files.

Input parameters:

- `format` (string)
- `graphId` (string, required): The diagram's graphId, as list_diagrams or get_diagram returns it. The id start_parse returned also works.

### `describe_resource` (~121 tokens)

Describe a resource

Describe one resource in an ArcSync diagram: its type, IaC attributes, and every relationship in and out (what it calls, reads, is attached to, or is contained by). `resource` may be the resource id, its name, or a substring; an ambiguous match returns the candidates to choose from.

Input parameters:

- `graphId` (string, required): The diagram's graphId, as list_diagrams or get_diagram returns it. The id start_parse returned also works.
- `resource` (string, required): Resource id, name, or a substring of either.

### `list_versions` (~92 tokens)

List diagram versions

List the saved versions of a diagram (one per re-parse, newest first) with the commit each came from and how much it changed. Pass a version's `timestamp` to get_delta to see what it changed. Version history is a Pro feature.

Input parameters:

- `graphId` (string, required): The diagram's graphId, as list_diagrams or get_diagram returns it. The id start_parse returned also works.

### `get_delta` (~124 tokens)

Get an infrastructure delta

Show what changed in a diagram's infrastructure. Without `version`, returns the pull-request delta for a PR-branch diagram: resources added, removed and changed compared with the base branch. With `version` (a timestamp from list_versions), compares that version with the one before it, or with the latest parse when `against` is "live".

Input parameters:

- `against` (string)
- `graphId` (string, required): The diagram's graphId, as list_diagrams or get_diagram returns it. The id start_parse returned also works.
- `version` (string)

### `start_parse` (~184 tokens)

Diagram a repository

Ask ArcSync to clone a GitHub repository and parse its infrastructure-as-code (Terraform, CloudFormation, AWS CDK, Pulumi, Azure ARM, Serverless Framework) into a diagram. Returns a graphId at once; poll get_parse_status until it completes, then call get_diagram. Uses one parse from the workspace's monthly quota (CDK and Pulumi also use a server-side synth), so call list_diagrams first and reuse a diagram that already exists. Private repositories need the ArcSync GitHub App installed.

Input parameters:

- `branch` (string): Defaults to the repository's default branch, or main when ArcSync cannot look it up. Pass it when you know it.
- `path` (string): Subdirectory holding the IaC, when it is not at the repository root.
- `repoUrl` (string, required): https://github.com/owner/repo

### `get_parse_status` (~95 tokens)

Check a parse

Report the progress of a parse started with start_parse: status (pending, running, completed, failed, cancelled), the current phase and percentage, and the error when it failed. Takes the graphId start_parse returned, or the canonical graphId a completed parse reports.

Input parameters:

- `graphId` (string, required): The diagram's graphId, as list_diagrams or get_diagram returns it. The id start_parse returned also works.

### `validate_diagram` (~103 tokens)

Validate an authored diagram

Check ArcSync diagram source (```arcsync blocks) locally, without pushing it: reports OK with node and edge counts, or INVALID with one line per problem (block:line:column, and a suggestion when one exists). Run it, fix every error, then call push_diagram.

Input parameters:

- `source` (string, required): The diagram as markdown holding ```arcsync fenced blocks (Mermaid flowchart or stateDiagram-v2 syntax with @{ } node metadata).

### `push_diagram` (~147 tokens)

Push an authored diagram

Validate ArcSync diagram source locally, then store it as a private diagram in the caller's workspace. Pushing the same diagramId again updates that diagram. Returns the canvas link and an embed link for Notion. Counts against the workspace's diagram and hourly limits; call validate_diagram first.

Input parameters:

- `diagramId` (string): Defaults to the `%% diagram:` id in the source's first block, else a slug of the source's title.
- `source` (string, required): The diagram as markdown holding ```arcsync fenced blocks (Mermaid flowchart or stateDiagram-v2 syntax with @{ } node metadata).
- `title` (string): Defaults to the source's own title.

### `get_diagram_source` (~59 tokens)

Get an authored diagram's source

Return the stored ArcSync source text of an authored diagram (one pushed with push_diagram), to edit and push again. Takes the graphId push_diagram returned.

Input parameters:

- `graphId` (string, required): The graphId push_diagram returned.

### `list_icons` (~76 tokens)

List diagram icons

List the icon ids a diagram node can use in `@{ icon: "..." }` (aws:lambda, azure:function-apps, gcp:cloud-storage, generic ones such as user), grouped by vendor. `query` filters by substring.

Input parameters:

- `query` (string): Case-insensitive substring, e.g. lambda.

## Diagnostics

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

## Score history

- 2026-11-05: 82
- 2026-11-04: 38
- 2026-11-03: 81
- 2026-11-02: 81
- 2026-11-01: 38

## Common questions

### What is the ArcSync MCP server?

ArcSync is an MCP server listed in the public MCP registry as io.github.VanLandinghamLabs/arcsync-mcp. Architecture graphs from Terraform, CDK, CloudFormation, Pulumi and ARM, for coding agents. This page covers its npm package (arcsync-mcp).

### Is the ArcSync MCP server safe to use?

ArcSync scores 82 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 ArcSync MCP server expose?

ArcSync exposes 11 tools: list_diagrams, get_diagram, describe_resource, list_versions, get_delta, and 6 more. Their descriptions and schemas cost roughly 1,219 tokens of context every time the server is loaded.

### Is the ArcSync MCP server still maintained?

ArcSync 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 ArcSync MCP server under?

ArcSync 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/arcsync-mcp
- Socket report: https://socket.dev/npm/package/arcsync-mcp
- Repository: https://github.com/VanLandinghamLabs/arcsync-mcp
- Website: https://arcsync.dev/docs/mcp
- Changelog RSS feed: https://verifymcp.io/servers/vanlandinghamlabs-arcsync-mcp/arcsync-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/vanlandinghamlabs-arcsync-mcp/arcsync-mcp.json
- HTML version of this page: https://verifymcp.io/servers/vanlandinghamlabs-arcsync-mcp/arcsync-mcp