Developers

Citation Safe, from inside your AI tools.

The Model Context Protocol (MCP) is an open standard that lets AI assistants like Claude call external tools directly, instead of you copy-pasting between a chat window and a browser tab. Citation Safe runs an MCP server at https://citationsafe.com/api/mcp so any MCP-compatible client — Claude Desktop, Claude Code, or your own agent — can check a citation, verify a whole brief, or search our phantom-citation registry without leaving the conversation.

Add it to Claude Desktop

Open your Claude Desktop config file (claude_desktop_config.json, under Settings → Developer → Edit Config) and add:

{
  "mcpServers": {
    "citation-safe": {
      "url": "https://citationsafe.com/api/mcp"
    }
  }
}

Restart Claude Desktop. You should see “citation-safe” listed under the tools (hammer) icon. This works for any other MCP client that supports the Streamable HTTP transport — point it at the same URL.

If you have an API key (see below), pass it as a bearer token instead of connecting anonymously:

{
  "mcpServers": {
    "citation-safe": {
      "url": "https://citationsafe.com/api/mcp",
      "headers": {
        "Authorization": "Bearer <your-api-key>"
      }
    }
  }
}

Tools

is_this_case_real(citation)

Deterministic existence check (Layer 1, no LLM) for one citation, e.g. "410 U.S. 113". Returns { exists, source, confidence, url }.

verify_brief(text)

Existence + quote-match (Layers 1–2, no LLM) on every citation found in a pasted excerpt. Returns an array of per-citation verdicts.

search_phantoms(query)

Looks up known AI-hallucinated (phantom) case citations by name or the AI system that produced them. Read-only public data; returns [] if nothing matches.

verify_citation(text) · verify_document(url) · get_verification(id) · batch_verify_citations(texts)

The full 3-layer engine (existence, quote match, and — on paid CitationSafe accounts — proposition support), for MCP clients authenticated with a Supabase account token. See /api/docs and /methodology for the full verdict contract.

search_sanctions(query?, court?)

Searches the public AI-hallucination court sanctions database backing /sanctions-database.

Access & rate limits

is_this_case_real, verify_brief, and search_phantoms are open to any MCP client, no account required:

Free — no API key, 5 checks/day per IP address, resets at UTC midnight.
API key — pass Authorization: Bearer <key> for unlimited access to those three tools. Key issuance is manual right now — email support@citationsafe.com with what you’re building and we’ll send one.

verify_citation, verify_document, get_verification, and batch_verify_citations use your existing CitationSafe account instead: connect with a Supabase auth token and your plan’s usual monthly limits apply (see pricing). search_sanctions is public and unmetered, same as the page it backs.

Transport

MCP Streamable HTTP, JSON-RPC 2.0, stateless (no session persisted between calls — each request is independent, which is what makes this safe to run on Vercel’s serverless functions). Supports initialize, tools/list, and tools/call.

Questions

Email support@citationsafe.com — whether that’s an API key request, a bug report, or a tool you wish existed.