# Dev error explainers (npm · dev-error-explainers)

Offline, deterministic cause and fix for Node, npm, Next.js, CORS and Postgres URL errors.

- Trust score: 79/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-03

## Components

- npm · `dev-error-explainers`: 79/100 (this document), [markdown](https://verifymcp.io/servers/mahdibrr-dev-error-explainers/dev-error-explainers.md), [page](https://verifymcp.io/servers/mahdibrr-dev-error-explainers/dev-error-explainers)

## Channel facts

- Registry: `npm`
- Package: `dev-error-explainers`
- Version: `0.2.0`
- 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 2026-10-03.

- **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 mahdibrr/dev-error-explainers).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 2 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 66/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 559 tokens (~559/item across 1 items; 1 tools + 0 resources), over budget; trim descriptions and params.
  - 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**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% 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 1 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 2 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (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 Dev error explainers MCP server?

Dev error explainers runs locally as an npm package, launched with npx -y dev-error-explainers. 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 mahdibrr-dev-error-explainers -- npx -y dev-error-explainers
```

### Cursor

```json
{
  "mcpServers": {
    "mahdibrr-dev-error-explainers": {
      "command": "npx",
      "args": [
        "-y",
        "dev-error-explainers"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "mahdibrr-dev-error-explainers": {
      "command": "npx",
      "args": [
        "-y",
        "dev-error-explainers"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add mahdibrr-dev-error-explainers -- npx -y dev-error-explainers
```

### opencode

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

### OpenClaw

```bash
openclaw mcp add mahdibrr-dev-error-explainers --command npx --arg -y --arg dev-error-explainers
```

### Hermes

```yaml
mcp_servers:
  mahdibrr-dev-error-explainers:
    command: "npx"
    args: ["-y", "dev-error-explainers"]
```

### Netclaw

```json
{
  "McpServers": {
    "mahdibrr-dev-error-explainers": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "dev-error-explainers"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add mahdibrr-dev-error-explainers -t stdio -c npx -a -y dev-error-explainers
```

### Other

```json
{
  "mcpServers": {
    "mahdibrr-dev-error-explainers": {
      "command": "npx",
      "args": [
        "-y",
        "dev-error-explainers"
      ]
    }
  }
}
```

## 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.

### 2026-10-01 (score 79, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-09-30 (score 64)

First indexed and scored.

## MCP tools (1)

### `explain_error` (~483 tokens)

Explain a developer error

Explain a concrete developer error message or log excerpt and return its documented cause and fix.

Call it when the user pastes (or you captured from a terminal/browser console) an actual error, for example:
\- Node.js ESM/CommonJS errors: ERR_REQUIRE_ESM, ERR_MODULE_NOT_FOUND, "Cannot use import statement outside a module", "require is not defined in ES module scope".
\- npm ERESOLVE / peer-dependency conflict logs from npm install.
\- Next.js `next build` / `next dev` output (module not found, heap out of memory, server/client component errors, prerender failures).
\- Browser CORS console errors ("has been blocked by CORS policy", preflight, Access-Control-Allow-Origin).
\- A postgres:// or postgresql:// connection string (DATABASE_URL, Supabase pooler/direct URLs) that fails to connect.
\- Postgres connection errors from Node.js apps: connect ECONNREFUSED / ETIMEDOUT on 5432, getaddrinfo ENOTFOUND, Prisma P1000/P1001/P1017, "password authentication failed", "no pg_hba.conf entry", "too many clients", self-signed certificate.
Pass the raw text verbatim, including the stack trace and the "Node.js vX" footer when present; do not paraphrase it.

Returns a short human-readable diagnosis (cause, why, ranked fixes with code, official source links) plus the same result as structured JSON.
If nothing is recognised it answers "No known error recognised — nothing guessed"; then rely on your own reasoning.

Fully offline and deterministic: no network, no LLM, same input gives the same output. Secrets it can recognise (URL passwords, Bearer/Basic tokens, JWTs, token/key query parameters) are masked in the output.

Input parameters:

- `client` (string): Optional database client for connection-string advice (default prisma).
- `error` (string, required): The raw error message or log excerpt, verbatim (max ~200 KB). Include the lines around the error: stack trace, npm log block, "Node.js vX" footer, or the full connection string.
- `node_version` (string): Optional Node.js version in use (e.g. "20.10.0"), used to tailor ESM/CommonJS advice. Usually detected from the error text itself.

Output parameters:

- `engine` (string): The code path that produced the diagnosis (src/contract.js).
- `matched` (boolean): True when at least one explainer recognised the input.
- `redactions` (integer): Number of values masked in the output.
- `results` (array): One Diagnosis per finding, most severe first (docs/CONTRACT.md); empty when matched is false.
- `tool` (string): Always "dev-error-explainers".
- `version` (string): Package version that produced the result.

## Diagnostics

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

## Score history

- 2026-10-03: 79
- 2026-10-02: 79
- 2026-10-01: 79
- 2026-09-30: 64

## Common questions

### What is the Dev error explainers MCP server?

Dev error explainers is an MCP server listed in the public MCP registry as io.github.mahdibrr/dev-error-explainers. Offline, deterministic cause and fix for Node, npm, Next.js, CORS and Postgres URL errors. This page covers its npm package (dev-error-explainers).

### Is the Dev error explainers MCP server safe to use?

Dev error explainers scores 79 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 3 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 Dev error explainers MCP server expose?

Dev error explainers exposes 1 tool: explain_error. Their descriptions and schemas cost roughly 483 tokens of context every time the server is loaded.

### Is the Dev error explainers MCP server still maintained?

Dev error explainers is still listed as active in the MCP registry. We last reached this channel on 3 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 Dev error explainers MCP server under?

Dev error explainers 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/dev-error-explainers
- Socket report: https://socket.dev/npm/package/dev-error-explainers
- Repository: https://github.com/mahdibrr/dev-error-explainers
- Website: https://github.com/mahdibrr/dev-error-explainers/blob/main/docs/MCP.md
- Changelog RSS feed: https://verifymcp.io/servers/mahdibrr-dev-error-explainers/dev-error-explainers.xml
- Changelog JSON feed: https://verifymcp.io/servers/mahdibrr-dev-error-explainers/dev-error-explainers.json
- HTML version of this page: https://verifymcp.io/servers/mahdibrr-dev-error-explainers/dev-error-explainers