Failmodes

Name: Failmodes
Author: elyngved

by elyngvedversion 0.1.0i★ 0iComputer or cloud

Registry nameio.github.elyngved/failmodes

How to install

What it does

MCP server for the Fail Modes taxonomy — a knowledge base of AI system failure modes

Connects Computer or cloud
Account or key No key needed
Category Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Passed 5/5 checks · What you ask goes through the maker’s server (www.failmodes.com) · ✓ Commands checked Nov 13, 2026

First: which AI do you use?

ClaudeWeb · app · phoneChatGPTWebClaude CodeTerminalCursorCode editorVS CodeCode editorOtherOther apps

Pick your app and the steps appear below.

Works with Claude · about 2 min

No key, nothing to install · Set it up once on claude.ai or the desktop app, then use it in chat · free accounts can add 1 · on Team/Enterprise an Owner adds it

Open Claude’s Connectors page
CustomizeConnectors
Done
Click “Add” → “Custom” → “Web” and fill in these 2 fields
Copy each value into the field with the same name in Claude, then click Continue
Name · NameFailmodes
Remote MCP server URL · Addresshttps://www.failmodes.com/api/mcp
Click Continue past the sign-in settings Claude detected · under Authentication choose what the maker says (Sign in now, Sign in when needed or No sign in), then click Add
Done
Turn it on in a chat
+ConnectorsFailmodes
Done
Try it
Use Failmodes and tell me what you can do for me, then show me one thing
✓ If Claude says it is using Failmodes or shows a Failmodes tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with ChatGPT, depending on your plan

Full MCP: ChatGPT Business, Enterprise or Edu on the web · Pro: connects with read/fetch permissions, so tools that change data may not work · Plus: not confirmed in OpenAI’s docs; if you see an add-custom-MCP option on the Plugins page you can try these steps · web only

Open ChatGPT’s add-MCP page on the web
Plugins+Add custom MCP server
Done
Fill in the name and address
Enter a name, paste the address under Connection, tick the risk warning and click Create as a plugin
Name · NameFailmodes
Connection · Addresshttps://www.failmodes.com/api/mcp
Done
Pick Failmodes in a chat
Start a new chat and pick Failmodes from your plugins before typing
Done
Try it
Use Failmodes and tell me what you can do for me, then show me one thing
✓ If ChatGPT says it is using Failmodes or shows a Failmodes tool in the answer, you are connected

Menu names checked against OpenAI’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Claude Code · about 2 min

No key, nothing to install

Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Done

Paste this command and press Enter

claude mcp add --transport http --scope user failmodes https://www.failmodes.com/api/mcp

Done

Type /mcp in Claude Code
You should see Failmodes listed as connected
Done
Try it
Use Failmodes and tell me what you can do for me, then show me one thing
✓ If Claude Code says it is using Failmodes or shows a Failmodes tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Cursor · about 2 min

No key, nothing to install

Click this button to open Cursor
Open in Cursor
Cursor asks you to confirm; click Install
Done
Open the AI chat in Cursor in Agent mode
Done
Try it
Use Failmodes and tell me what you can do for me, then show me one thing
✓ If Cursor says it is using Failmodes or shows a Failmodes tool in the answer, you are connected

Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with VS Code · about 2 min

No key, nothing to install

Click this button to open VS Code
Open in VS Code
VS Code asks you to confirm; click Install
Done
Open the AI chat in VS Code in Agent mode
Done
Try it
Use Failmodes and tell me what you can do for me, then show me one thing
✓ If VS Code says it is using Failmodes or shows a Failmodes tool in the answer, you are connected

Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Other apps that use MCP, such as Windsurf, Zed or Gemini CLI, each add servers differently. See how in the app list.

See every app that uses MCP →

Address for apps that connect over the web

Addresshttps://www.failmodes.com/api/mcp

JSON settings are under “For developers” below

Stuck? Ask people who use Failmodes💬 Discussion →

For developers: Terminal commands and JSON settings

Over the web

Claude Code

claude mcp add --transport http --scope user failmodes https://www.failmodes.com/api/mcp

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "failmodes": {
      "url": "https://www.failmodes.com/api/mcp"
    }
  }
}

VS Code (mcp.json)

{
  "servers": {
    "failmodes": {
      "type": "http",
      "url": "https://www.failmodes.com/api/mcp"
    }
  }
}

Installed on your computer

Claude Code

claude mcp add --scope user failmodes -- npx -y failmodes-mcp

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "failmodes": {
      "command": "npx",
      "args": [
        "-y",
        "failmodes-mcp"
      ]
    }
  }
}

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "failmodes": {
      "command": "npx",
      "args": [
        "-y",
        "failmodes-mcp"
      ]
    }
  }
}

VS Code (mcp.json)

{
  "servers": {
    "failmodes": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "failmodes-mcp"
      ]
    }
  }
}

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

At a glance

GitHub stars i: 0
Downloads per weeki: 43/wk
Licence i: MIT
Connection: Computer or cloud
Transport: stdio, streamable-http
Latest versioni: 0.1.0
Categoryi: Search & AI memory
Published to registryi: Jul 5, 2026
Code last changedi: Jul 5, 2026
Maker: elyngved
Packages: npm: failmodes-mcp
Repo: elyngved/failmodes-mcp
Registry status: Active

Which apps can use it

Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.

Connect over the internet in

Claude ChatGPT Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Open WebUI Raycast

Run on your computer in

Claude Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Raycast

All apps, with pros and cons →

What it can do

Tool names and descriptions exactly as the server reported them on Nov 15, 2026. The maker wrote them, not us; we show them as plain text.

search_failure_modes
Search the Fail Modes taxonomy by symptom text or keyword phrase. Returns ranked matches with id, name, category, and matched context.
get_failure_mode
Retrieve the full structured record for a single failure mode by its ID slug (e.g. 'citation-hallucination', 'sycophancy').
list_categories
List all taxonomy categories with their IDs, names, descriptions, and mode counts.
list_modes
List failure modes, optionally filtered to a single category by category ID.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 15, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account elyngved, which owns the repo
✓ Pass
Still maintained
Code last changed 4 months ago
✓ Pass
Has a licence
Uses MIT
✓ Pass
Endpoint responds
Responded in 372 ms (HTTP 200)
– Not applicable
Sign-in with OAuth
No sign-in needed
✓ Pass
No hidden instructions in tool descriptions
Read 4 tool descriptions and found no hidden instructions to the AI

Published vulnerabilities (OSV.dev)

Not checked yet

What we check → · JSON

Makers: ask for a re-check or report wrong info

Discussion

Ask, share a tip or report that it does not work. Sorted by what people marked helpful.

No posts yet. Be the first to ask or share.

Posts here are written by users, not the PopNx team.

User reviews

No reviews yet

Compared with others in Search & AI memoryi

More stars than 0% of the other 6178 servers in this category
Published to the registry more recently than 18% of the other 6178 servers in this category
Basic checks equal to or better than 100% of the other 6178 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Failmodes safe?

It passed 5 of 5 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed 4 months ago, and the latest version (0.1.0) reached the registry 4 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT on the web (full MCP on Business and above; Pro read-only).

What can I use instead?

In the same category: OpenSEO, Exa, Mockserver, Microsoft Learn MCP, Docs

Similar alternatives

Same category, other makers, commands already checked. Official ones first, then by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

OpenSEO

Keyword research, site audits, rank tracking and AI visibility for your AI agent.

by every-appWidely used★ 27.8KUpdated yesterday

Runs in the cloud✓ everyapp.com

How to connect

Exa

Connect AI agents to Exa for web search, content fetching, and multi-step research.

by exa-labsWidely used★ 5.2KUpdated 2 months ago

Runs in the cloud✓ service owner · exa.aiTried by the PopNx team

How to connect

Mockserver

Mock, record/replay, verify and chaos-test any HTTP, REST, gRPC or LLM dependency over MCP.

by mock-serverGrowing★ 5KUpdated 19 days ago

Runs on your computer✓ service owner · mock-server.com

Install

Microsoft Learn MCP

Official Microsoft Learn MCP Server – real-time, trusted docs & code samples for AI and LLMs.

by MicrosoftDocsWidely used★ 2KUpdated 12 months ago

Runs in the cloud✓ service owner · microsoft.comTried by the PopNx team

How to connect

Docs

Search and read Empryo's documentation. Read-only, no auth, no local access.

by proxysoulGrowing★ 1.6KUpdated 2 months ago

Runs in the cloud✓ empryo.com

How to connect

OpenSEO — Runs in the cloud, nothing to install · No key needed
Exa — Runs in the cloud, nothing to install · No key needed · In Claude’s directory
Mockserver — Installs on your computer · No key needed
Microsoft Learn MCP — Runs in the cloud, nothing to install · No key needed · In Claude’s directory
Docs — Runs in the cloud, nothing to install · No key needed

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

failmodes-mcp

MCP server for the Fail Modes taxonomy — a machine-readable knowledge base of AI system failure modes.

Provides four tools over 100+ canonical failure mode records spanning factuality, alignment, planning, code generation, instruction following, and more.

Tools

Tool	Description
`search_failure_modes`	Search by symptom text or keyword phrase. Returns ranked matches.
`get_failure_mode`	Retrieve the full structured record for a failure mode by ID slug.
`list_categories`	List all taxonomy categories with descriptions and mode counts.
`list_modes`	List all modes, optionally filtered by category ID.

Quick Start

No installation required — run directly with npx:

npx failmodes-mcp

Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

"mcpServers": { "failmodes": { "command": "npx", "args": ["-y", "failmodes-mcp"] } } }

Cursor / VS Code

Add to your MCP settings file:

"mcpServers": { "failmodes": { "command": "npx", "args": ["-y", "failmodes-mcp"] } } }

Remote (no install required)

A hosted Streamable HTTP version is also available — no npm package needed:

"mcpServers": { "failmodes": { "url": "https://www.failmodes.com/api/mcp" } } }

How It Works

On first tool call, the server fetches current taxonomy data from failmodes.com and caches it in memory for the duration of the session. Requires internet access.

The stdio transport makes this compatible with any MCP client that supports running local processes (Claude Desktop, Cursor, VS Code, etc.).

License

MIT

Failmodes

What it does

Install

Open Claude’s Connectors page

Click “Add” → “Custom” → “Web” and fill in these 2 fields

Turn it on in a chat

Try it

Open ChatGPT’s add-MCP page on the web

Fill in the name and address

Pick Failmodes in a chat

Try it

Open Terminal

Paste this command and press Enter

Type /mcp in Claude Code

Try it

Click this button to open Cursor

Open the AI chat in Cursor in Agent mode

Try it

Click this button to open VS Code

Open the AI chat in VS Code in Agent mode

Try it

Over the web

Installed on your computer

At a glance

Which apps can use it

Related guides

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Published vulnerabilities (OSV.dev)

Discussion

User reviews

Compared with others in Search & AI memoryi

Common questions

Similar alternatives

OpenSEO

Exa

Mockserver

Microsoft Learn MCP

Docs

README from the maker

failmodes-mcp

Tools

Quick Start

Configuration

Claude Desktop

Cursor / VS Code

Remote (no install required)

How It Works

Links

License