Citation Check
Does a cited URL exist, and does the source name what your claim names?
What it can do
What data it sees
Do you need an account
No: the server works without sign-in
Does a cited URL exist, and does the source name what your claim names? Two answers.
How to connect
How to connect Citation Check to Claude
The server address to paste into Claude settings:
https://exmachina-ai.fly.dev/verify
- Open Claude (claude.ai or the desktop app).
- Go to Settings → Connectors.
- Click Add custom connector.
- Paste the server address copied below into Remote MCP server URL and click Add.
- In a chat, click + → Connectors and switch the new connector on.
Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.
Authorization
After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.
How to connect Citation Check to ChatGPT
The server address to paste into ChatGPT settings:
https://exmachina-ai.fly.dev/verify
- Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
- Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
- Open Settings → Connectors and click Create.
- Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
- Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
- In a new chat open + → Apps/Connectors and enable the connector.
OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.
Authorization
On first use ChatGPT opens the service's sign-in window. Sign in and approve access.
How to connect Citation Check to Cursor
The server address to paste into Cursor settings:
https://exmachina-ai.fly.dev/verify
Fastest: click Open in Cursor below and confirm the prompt.
Manually:
- In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
- Paste the JSON copied below into
~/.cursor/mcp.json(per project:.cursor/mcp.jsonin the repo root). - Save the file. The server appears in the MCP list; authorize it there if asked.
Authorization
If the service needs sign-in, an authorize button appears next to the server in the MCP list.
Server tool list (2)
Raw names from tools/list. Only developers need these.
| check_citation | Fetch a URL and report whether it exists, and whether the source names the same entity as the claim you attach to it. These are two different questions and conflating them is the failure this exists to catch: a URL can return 200 and describe a different gene entirely. No account needed, nothing is stored about you. |
| verdict_meanings | The exact semantics of every status and relevance value, including what this checker cannot determine. Read once before trusting a verdict. |