# HSM Kit (npm · @hsmkit/mcp-server)

Local-first Base64, Luhn, key-component XOR, and synthetic ISO-0 PIN block tools.

- Trust score: 80/100 (high trust)
- Change this week: −1
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-02

## Components

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

## Channel facts

- Registry: `npm`
- Package: `@hsmkit/mcp-server`
- Version: `0.1.0`
- 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 2026-10-02.

- **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 4 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 71/100
  - Repository presence not verified: we could not reach the forge to check. This is a gap on our side, not a finding about the repository.
  - Cryptographically verified build provenance (signed, bound to hsm-kit/hsmkit).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 8 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 80/100
  - AI-judged instruction clarity (excellent).
  - Tool/resource definitions use about 231 tokens (~38/item across 6 items; 6 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 30/100
  - Stability observed for 9 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 90/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 71% 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 6 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 6 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 HSM Kit MCP server?

HSM Kit runs locally as an npm package, launched with npx -y @hsmkit/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 hsm-kit-hsmkit -- npx -y @hsmkit/mcp-server
```

### Cursor

```json
{
  "mcpServers": {
    "hsm-kit-hsmkit": {
      "command": "npx",
      "args": [
        "-y",
        "@hsmkit/mcp-server"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "hsm-kit-hsmkit": {
      "command": "npx",
      "args": [
        "-y",
        "@hsmkit/mcp-server"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add hsm-kit-hsmkit -- npx -y @hsmkit/mcp-server
```

### opencode

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

### OpenClaw

```bash
openclaw mcp add hsm-kit-hsmkit --command npx --arg -y --arg @hsmkit/mcp-server
```

### Hermes

```yaml
mcp_servers:
  hsm-kit-hsmkit:
    command: "npx"
    args: ["-y", "@hsmkit/mcp-server"]
```

### Netclaw

```json
{
  "McpServers": {
    "hsm-kit-hsmkit": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@hsmkit/mcp-server"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add hsm-kit-hsmkit -t stdio -c npx -a -y @hsmkit/mcp-server
```

### Other

```json
{
  "mcpServers": {
    "hsm-kit-hsmkit": {
      "command": "npx",
      "args": [
        "-y",
        "@hsmkit/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.

### 2026-10-02 (score 80, −5)

- [security regression] Provenance: pass → unverified

### 2026-10-01 (score 85, +4)

- [functional improvement] Stability: unverified → 0.27

### 2026-09-28 (score 81, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-25 (score 81, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-24 (score 81, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-09-23 (score 66)

First indexed and scored.

## MCP tools (6)

### `luhn_calculate_check_digit` (~43 tokens)

Calculate the Luhn (Mod 10) check digit for a digits-only payload.

Input parameters:

- `payload` (string, required): Digits without the final check digit

### `luhn_validate` (~37 tokens)

Validate a complete number using the Luhn (Mod 10) algorithm.

Input parameters:

- `value` (string, required): Complete digits including the check digit

### `xor_key_components` (~34 tokens)

XOR equal-length hexadecimal key components for synthetic interoperability tests.

Input parameters:

- `components` (array, required): Two or more equal-length hexadecimal values

### `iso0_pin_block` (~64 tokens)

Generate an ISO 9564-1 format 0 clear PIN block from synthetic PIN and PAN test data.

Input parameters:

- `pan` (string, required): Synthetic PAN containing 13 to 19 digits
- `pin` (string, required): Synthetic PIN containing 4 to 12 digits

### `base64_encode` (~26 tokens)

Encode UTF-8 text as standard Base64.

Input parameters:

- `text` (string, required)

### `base64_decode` (~27 tokens)

Decode standard Base64 into UTF-8 text.

Input parameters:

- `base64` (string, required)

## Diagnostics

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

## Score history

- 2026-10-02: 80
- 2026-10-01: 85
- 2026-09-30: 81
- 2026-09-29: 81
- 2026-09-28: 81
- 2026-09-27: 81
- 2026-09-26: 81
- 2026-09-25: 81
- 2026-09-24: 81
- 2026-09-23: 66

## Common questions

### What is the HSM Kit MCP server?

HSM Kit is an MCP server listed in the public MCP registry as io.github.hsm-kit/hsmkit. Local-first Base64, Luhn, key-component XOR, and synthetic ISO-0 PIN block tools. This page covers its npm package (@hsmkit/mcp-server).

### Is the HSM Kit MCP server safe to use?

HSM Kit scores 80 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 2 October 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 HSM Kit MCP server expose?

HSM Kit exposes 6 tools: luhn_calculate_check_digit, luhn_validate, xor_key_components, iso0_pin_block, base64_encode, base64_decode. Their descriptions and schemas cost roughly 231 tokens of context every time the server is loaded.

### Is the HSM Kit MCP server still maintained?

HSM Kit is still listed as active in the MCP registry. We last reached this channel on 2 October 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 HSM Kit MCP server under?

HSM Kit 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/@hsmkit/mcp-server
- Socket report: https://socket.dev/npm/package/@hsmkit/mcp-server
- Repository: https://github.com/hsm-kit/hsmkit
- Website: https://hsmkit.com/
- Changelog RSS feed: https://verifymcp.io/servers/hsm-kit-hsmkit/hsmkit-mcp-server.xml
- Changelog JSON feed: https://verifymcp.io/servers/hsm-kit-hsmkit/hsmkit-mcp-server.json
- HTML version of this page: https://verifymcp.io/servers/hsm-kit-hsmkit/hsmkit-mcp-server