# Webhook Crash Lab (npm · webhook-crash-lab-mcp)

Lets coding agents crash-test webhook handlers and re-run until they survive retries.

- Trust score: 68/100 (medium)
- Change this week: +15
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- npm · `webhook-crash-lab-mcp`: 68/100 (this document), [markdown](https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp.md), [page](https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp)

## Channel facts

- Registry: `npm`
- Package: `webhook-crash-lab-mcp`
- Version: `0.2.4`
- 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**: 98/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 30 of 94 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 45/100
  - Source repository is publicly reachable at the declared URL.
  - Provenance check failed: no build-provenance attestation is published.
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 10 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 71/100
  - AI-judged instruction clarity (good).
  - Tool/resource definitions use about 346 tokens (~86/item across 4 items; 4 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 89/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 63% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **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 4 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.

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the Webhook Crash Lab MCP server?

Webhook Crash Lab runs locally as an npm package, launched with npx -y webhook-crash-lab-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 krrishkumar125-webhook-crash-lab-mcp -- npx -y webhook-crash-lab-mcp
```

### Cursor

```json
{
  "mcpServers": {
    "krrishkumar125-webhook-crash-lab-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "webhook-crash-lab-mcp"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "krrishkumar125-webhook-crash-lab-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "webhook-crash-lab-mcp"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add krrishkumar125-webhook-crash-lab-mcp -- npx -y webhook-crash-lab-mcp
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "krrishkumar125-webhook-crash-lab-mcp": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "webhook-crash-lab-mcp"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add krrishkumar125-webhook-crash-lab-mcp --command npx --arg -y --arg webhook-crash-lab-mcp
```

### Hermes

```yaml
mcp_servers:
  krrishkumar125-webhook-crash-lab-mcp:
    command: "npx"
    args: ["-y", "webhook-crash-lab-mcp"]
```

### Netclaw

```json
{
  "McpServers": {
    "krrishkumar125-webhook-crash-lab-mcp": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "webhook-crash-lab-mcp"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add krrishkumar125-webhook-crash-lab-mcp -t stdio -c npx -a -y webhook-crash-lab-mcp
```

### Other

```json
{
  "mcpServers": {
    "krrishkumar125-webhook-crash-lab-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "webhook-crash-lab-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.

### 2026-10-30 (score 68, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-10-29 (score 53)

First indexed and scored.

## MCP tools (4)

### `run_crash_lab` (~162 tokens)

Run webhook-crash-lab

Replay hostile webhook deliveries (duplicates, concurrent duplicates, out-of-order events, forged/missing/stale signatures, malformed JSON) against the handler described by a crash-lab config file, and return structured failures with fix hints. Use a TEST database and test secret only. Create a config with `npx webhook-crash-lab init` if none exists.

Input parameters:

- `configPath` (string, required): Path to a crash-lab config (.mjs, .js, .cjs, .ts, .mts or .cts), relative to cwd
- `cwd` (string): Project directory; defaults to the server working directory
- `reportPath` (string): Also write the full JSON report here
- `scenarios` (array): Run only these scenarios

Output parameters:

- `failures` (array)
- `name` (string)
- `nextSteps` (array)
- `notTested` (array)
- `ok` (boolean)
- `reportPath` (string)
- `scenarios` (array)
- `summary` (object)

### `run_demo` (~69 tokens)

Run the built-in demo

Run crash-lab against its built-in demo credits app. "broken" shows the typical AI-generated Stripe handler failing; "fixed" shows the same app done right. Needs no config. Use it to show what crash-lab checks before setting up a real config.

Input parameters:

- `mode` (string)

Output parameters:

- `failures` (array)
- `name` (string)
- `nextSteps` (array)
- `notTested` (array)
- `ok` (boolean)
- `reportPath` (string)
- `scenarios` (array)
- `summary` (object)

### `explain_report` (~78 tokens)

Explain a crash-lab report

Read a JSON report produced by `webhook-crash-lab run --json <file>` (e.g. from CI) and return the failures in fix order, with why/fix hints and next steps.

Input parameters:

- `cwd` (string)
- `report`: Report JSON, as text or object
- `reportPath` (string)

Output parameters:

- `failures` (array)
- `name` (string)
- `nextSteps` (array)
- `notTested` (array)
- `ok` (boolean)
- `reportPath` (string)
- `scenarios` (array)
- `summary` (object)

### `list_scenarios` (~37 tokens)

List crash-lab scenarios

List every scenario crash-lab can run, with what it sends, why it matters in production, and how to fix a failure.

Output parameters:

- `scenarios` (array)

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp#diagnostics

## Score history

- 2026-11-05: 68
- 2026-11-04: 68
- 2026-11-03: 68
- 2026-11-02: 68
- 2026-11-01: 68
- 2026-10-31: 68
- 2026-10-30: 68
- 2026-10-29: 53

## Common questions

### What is the Webhook Crash Lab MCP server?

Webhook Crash Lab is an MCP server listed in the public MCP registry as io.github.Krrishkumar125/webhook-crash-lab-mcp. Lets coding agents crash-test webhook handlers and re-run until they survive retries. This page covers its npm package (webhook-crash-lab-mcp).

### Is the Webhook Crash Lab MCP server safe to use?

Webhook Crash Lab scores 68 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. 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 Webhook Crash Lab MCP server expose?

Webhook Crash Lab exposes 4 tools: run_crash_lab, run_demo, explain_report, list_scenarios. Their descriptions and schemas cost roughly 346 tokens of context every time the server is loaded.

### Is the Webhook Crash Lab MCP server still maintained?

Webhook Crash Lab 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 Webhook Crash Lab MCP server under?

Webhook Crash Lab 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/webhook-crash-lab-mcp
- Socket report: https://socket.dev/npm/package/webhook-crash-lab-mcp
- Repository: https://github.com/Krrishkumar125/webhook-crash-lab-mcp
- Changelog RSS feed: https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp.json
- HTML version of this page: https://verifymcp.io/servers/krrishkumar125-webhook-crash-lab-mcp/webhook-crash-lab-mcp