Crossref MCP Server

A Model Context Protocol (MCP) server for interacting with the Crossref API.

Features

• Search works by title
• Search works by author
• Get work details by DOI

Installation

{
  "mcpServers": {
    "crossref": {
      "command": "npx",
      "args": [
        "-y",
        "@botanicastudios/crossref-mcp"
      ]
    }
  }
}

Usage

The server provides three main tools:

1. Search by Title

Search for works in Crossref by title:

// Example: Search for works containing "quantum computing" in the title
{
  "title": "quantum computing",
  "rows": 5  // Optional, defaults to 5
}

2. Search by Author

Search for works in Crossref by author:

// Example: Search for works by "Einstein"
{
  "author": "Einstein",
  "rows": 5  // Optional, defaults to 5
}

3. Get Work by DOI

Retrieve a specific work using its DOI:

// Example: Get work with DOI "10.1088/1742-6596/1398/1/012023"
{
  "doi": "10.1088/1742-6596/1398/1/012023"
}

Response Format

All responses are returned as structured JSON objects with the following format:

For successful searches:

{
  "status": "success",
  "query": {
    /* the original query parameters */
  },
  "count": 5,
  "results": [
    {
      "title": "Work title",
      "authors": [
        {
          "given": "First name",
          "family": "Last name",
          "name": "First name Last name"
        }
      ],
      "published": {
        "dateParts": [2023, 1, 15],
        "dateString": "2023-1-15"
      },
      "type": "journal-article",
      "doi": "10.xxxx/xxxxx",
      "url": "https://doi.org/10.xxxx/xxxxx",
      "container": "Journal Name",
      "publisher": "Publisher Name",
      "issue": "1",
      "volume": "42",
      "abstract": "This is the abstract of the work, if available."
    }
    // additional results...
  ]
}

For single DOI lookup:

{
  "status": "success",
  "query": { "doi": "10.xxxx/xxxxx" },
  "result": {
    // work details as shown above
  }
}

For errors or no results:

{
  "status": "error" | "no_results" | "not_found",
  "message": "Error message" | null,
  "query": { /* the original query parameters */ }
}

Testing

The server comes with a comprehensive test suite using Vitest. Tests cover all available tools and include various scenarios including successful responses, empty results, and error handling.

Running Tests

npm test

Test Structure

The tests use Vitest’s mocking capabilities to simulate Crossref API responses without making actual network requests. The test structure includes:

1. Mock Data: Sample responses for title searches, author searches, and DOI lookups
2. Mock Handlers: Testing versions of the handler functions in mcp-server-test-handlers.js
3. Test Cases: Tests for all tools covering:
   • Successful API responses
   • Empty result sets
   • Error handling and network failures

Extending Tests

To add more test cases:

1. Add new mock data to the test file if needed
2. Create additional test cases in the relevant describe block
3. Use the mockFetchResponse() helper to simulate API responses

Example:

it("should handle a new edge case", async () => {
  // Mock the response
  mockFetchResponse({
    // Your sample response data
  });

  // Call the handler
  const result = await handlers.searchByTitle({ title: "example" });

  // Assert the expected results
  expect(result).toMatchObject({
    // Expected response structure
  });
});