# GenClass (npm · @genclass/mcp)

Find race conditions in your web app by reordering its responses, replay one, prove the fix.

- Trust score: 77/100 (medium)
- Change this week: −2
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- npm · `@genclass/mcp`: 77/100 (this document), [markdown](https://verifymcp.io/servers/genclass-dev-genclass/genclass-mcp.md), [page](https://verifymcp.io/servers/genclass-dev-genclass/genclass-mcp)

## Channel facts

- Registry: `npm`
- Package: `@genclass/mcp`
- Version: `0.2.1`
- 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**: 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**: 71/100
  - Repository check failed: the declared repository URL redirects; it must resolve directly.
  - Cryptographically verified build provenance (signed, bound to genclass-dev/GenClass-lib).
  - Clear OSI-approved license (Apache-2.0).
  - Actively maintained (last published 7 days ago).
  - Security-disclosure policy not yet verified: we couldn't inspect the source repository.
- **Schema Quality & AI Usability**: 60/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1878 tokens (~208/item across 9 items; 9 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 33/100
  - Stability observed for 10 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 91/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 73% 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 9 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 10 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 GenClass MCP server?

GenClass runs locally as an npm package, launched with npx -y @genclass/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 genclass-dev-genclass -- npx -y @genclass/mcp
```

### Cursor

```json
{
  "mcpServers": {
    "genclass-dev-genclass": {
      "command": "npx",
      "args": [
        "-y",
        "@genclass/mcp"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "genclass-dev-genclass": {
      "command": "npx",
      "args": [
        "-y",
        "@genclass/mcp"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add genclass-dev-genclass -- npx -y @genclass/mcp
```

### opencode

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

### OpenClaw

```bash
openclaw mcp add genclass-dev-genclass --command npx --arg -y --arg @genclass/mcp
```

### Hermes

```yaml
mcp_servers:
  genclass-dev-genclass:
    command: "npx"
    args: ["-y", "@genclass/mcp"]
```

### Netclaw

```json
{
  "McpServers": {
    "genclass-dev-genclass": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@genclass/mcp"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add genclass-dev-genclass -t stdio -c npx -a -y @genclass/mcp
```

### Other

```json
{
  "mcpServers": {
    "genclass-dev-genclass": {
      "command": "npx",
      "args": [
        "-y",
        "@genclass/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 77, 0)

- [functional regression] Security disclosure: pass → unverified

### 2026-11-03 (score 77, −4)

- [security regression] Source repository: pass → fail

### 2026-11-01 (score 81, +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.

### 2026-10-30 (score 80, +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.

### 2026-10-29 (score 79, +26)

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

### 2026-10-28 (score 53, −26)

- [security regression] Malware scan: pass → unverified
- [security regression] Known CVEs: pass → unverified
- [functional regression] Dependency health: pass → unverified
- [functional] Package version: 0.2.0 → 0.2.1

### 2026-10-27 (score 79, +1)

No change was recorded against any check on this day. Stability & Change Management went from 0 to 3. That category is still filling its 30-day observation window: 0 days of observed history at the previous scan, 1 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-26 (score 78)

First indexed and scored.

## MCP tools (9)

### `genclass_status` (~56 tokens)

GenClass status

Which pages on this machine are connected to GenClass (route, schedule, model state), counts of findings by kind, the explore session and armed replays. Call it first in a web project, and before you test a page.

### `genclass_findings` (~164 tokens)

GenClass findings

What GenClass recorded in pages on this machine, ranked and deduplicated with counts: races found by explore (final state depends on response order), responses that overwrote newer data, uncaught errors (with the click and request before them), the same request sent twice by two clicks, the on-device model's detections, visual checks. Use when the user reports an intermittent bug, after changing data-fetching or submit code, or before saying a UI change is done.

Input parameters:

- `kind` (string): Only this kind.
- `limit` (number): At most this many (default 20).
- `route` (string): Only this page path, e.g. /checkout.
- `since_minutes` (number): Only findings seen in the last N minutes.

### `genclass_explain` (~85 tokens)

Explain a GenClass finding

Everything about one finding: what happened in causal order (click → request → response → state write), the recorded steps and delivery order, what differed from the request-order baseline, the model's facts, how to replay it exactly, and a Playwright regression test that fails while the bug is there.

Input parameters:

- `id` (string, required): Finding id, e.g. f3.

### `genclass_explore` (~319 tokens)

Explore response orders

Find races before users do. action "start" arms the next page loads: 2 baselines with responses in request order, then `runs` loads where overlapping responses arrive in a seeded different order (optionally slower, or with `focus` endpoints last). Run the same scenario once per armed load, then action "report": each load's final state is compared with the baseline; a difference in what the page shows, its form values, the requests it sent or its errors depends on network timing (a race), and comes with a seed that replays it. Store values that differ while the page is the same are listed apart as internal state. Without `route`, the page of the first armed load is the page under test; set `route` when the scenario loads several pages. Armed loads expire after 30 minutes. "stop" disarms.

Input parameters:

- `action` (string, required)
- `focus` (array): Request signatures to deliver last, e.g. ["PUT /api/notes/:id"] (one production flagged).
- `id` (string): report: the session id (default the latest).
- `route` (string): Only arm page loads of this path (default: any page).
- `runs` (number): Seeded loads after the 2 baselines (default 6, max 50).
- `seed` (number): First seed (default 1).
- `slow_ms` (number): Also add up to this much latency per response (a slow network), e.g. 800.

### `genclass_replay` (~114 tokens)

Replay a finding

Reproduce one finding exactly. action "arm": the next page load of the finding's route gets the delivery order that produced it; do the same steps (genclass_explain lists them). action "result": whether that replay reproduced it. Use before a fix to confirm the bug and after it to prove the fix.

Input parameters:

- `action` (string, required)
- `id` (string, required): Finding id, e.g. f3.
- `times` (number): arm: how many page loads (default 1).

### `genclass_analytics` (~124 tokens)

GenClass analytics

What GenClass measured about the app. local: per-endpoint request counts, median and p95 latency, error rates and failure streaks; per-page runs, errors and overwritten fields; learned relations between fields and learned flows, from pages on this machine. production: the GenClass dashboard's sessions, detections by diagnosis and page, and latest decisions (needs GENCLASS_DASHBOARD, the dashboard's private link; "sample" reads the public sample).

Input parameters:

- `range` (string)
- `route` (string)
- `source` (string)

### `genclass_setup` (~59 tokens)

Set up GenClass

The lines to add so this project's dev build connects to GenClass (detects Vite, Next.js and others from package.json), how to check it works, and this MCP client's config lines for keeping the server configured. It changes no file.

### `genclass_scan` (~301 tokens)

Scan a page for visual bugs

Audit one page in one step with GenClass's 23 measured visual checks: text you cannot read against its background, images, fonts, stylesheets and media that failed to load, a page that scrolls sideways on a phone, controls stuck under fixed bars, layers that swallow clicks, covered dialogs, template leaks like {{name}} or [object Object]. It loads the URL headless at desktop and phone sizes in Playwright's Chromium on this machine (when that is missing it says how to install it); hosted: true runs it on the genclass.dev page check instead, which adds accessibility, speed and security audits, takes public pages only and is the one case where the URL leaves this machine and returns a score and each problem with its element, selector and a suggested CSS fix, worst first, plus the JSON report. Use it before you call a page or UI change done, after CSS or layout changes, and on a site you do not own. Works on any URL, including the dev server (http://localhost:5173/); no page needs GenClass installed.

Input parameters:

- `hosted` (boolean): Run on the genclass.dev page check instead of this machine (public pages only; adds accessibility, speed and security).
- `phone` (boolean): The phone size only (default: desktop and phone).
- `url` (string, required): The page, e.g. http://localhost:5173/pricing or https://example.com.

### `genclass_clear` (~41 tokens)

Clear GenClass records

Forget recorded runs and findings on this machine (all, findings or runs), e.g. after a fix to start clean.

Input parameters:

- `what` (string)

## Diagnostics

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

## Score history

- 2026-11-05: 77
- 2026-11-04: 77
- 2026-11-03: 77
- 2026-11-02: 81
- 2026-11-01: 81
- 2026-10-31: 80
- 2026-10-30: 80
- 2026-10-29: 79
- 2026-10-28: 53
- 2026-10-27: 79
- 2026-10-26: 78

## Common questions

### What is the GenClass MCP server?

GenClass is an MCP server listed in the public MCP registry as io.github.genclass-dev/genclass. Find race conditions in your web app by reordering its responses, replay one, prove the fix. This page covers its npm package (@genclass/mcp).

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

GenClass scores 77 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 GenClass MCP server expose?

GenClass exposes 9 tools: genclass_status, genclass_findings, genclass_explain, genclass_explore, genclass_replay, and 4 more. Their descriptions and schemas cost roughly 1,263 tokens of context every time the server is loaded.

### Is the GenClass MCP server still maintained?

GenClass 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 GenClass MCP server under?

GenClass declares the Apache-2.0 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/@genclass/mcp
- Socket report: https://socket.dev/npm/package/@genclass/mcp
- Website: https://genclass.dev/
- Changelog RSS feed: https://verifymcp.io/servers/genclass-dev-genclass/genclass-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/genclass-dev-genclass/genclass-mcp.json
- HTML version of this page: https://verifymcp.io/servers/genclass-dev-genclass/genclass-mcp