Journal Data MCP Service

In addition to the REST API, we also provide an MCP (Model Context Protocol) service, which connects journal query capabilities directly to AI clients that support MCP (Claude Desktop, Claude Code, Cherry Studio, Cline, etc.).

Once connected, you can ask the AI directly in conversation:

"Look up the impact factor and quartile for J Med Chem and Nature Communications, and check whether either is a warning or predatory journal."

The AI will automatically call the tools to complete the query — no need to write any requests by hand.

Basic Information

• Service address: https://api.byteslink.cn/journals/mcp
• Transport protocol: Streamable HTTP (remote service, no local installation needed)
• Authentication: API Key, shared with the REST API (same Key, starting with pp_), generated under "User Center → My API"
• Billing and rate limiting: identical to the REST API, see Billing and Rate Limiting

Two ways to pass the Key are supported, use either one:

X-API-Key: pp_xxxxxxxxxxxxxxxx

or (for clients that only provide a Bearer Token field):

Authorization: Bearer pp_xxxxxxxxxxxxxxxx

Tools Provided

Tool	Function	Corresponding Endpoint
query_impact_factors	Batch query impact factor (JIF / JIF5), JCR quartile, CAS quartile	POST /dev/impact-factors/
check_warnings	Check whether a journal is on the CAS International Journal Early Warning List or the predatoryjournals.org predatory journal list	POST /dev/warnings/

Both tools take the same input: a journals list of names, 1–20 items, supporting common abbreviations (e.g. J Med Chem) and full names, case-insensitive. Each tool call is billed once (regardless of how many journals are queried), so batch queries save quota.

check_warnings returns is_warning: true on a hit against either list; the specific matched sources are listed in sources (see the API Reference for field details).

Client Configuration

Claude Code

Connect with a single command:

claude mcp add --transport http paperpop-journals \
  https://api.byteslink.cn/journals/mcp \
  --header "X-API-Key: pp_xxxxxxxx"

Verify: running claude mcp list should show paperpop-journals, then you can query directly in conversation.

Claude Desktop

Claude Desktop currently bridges to the remote HTTP service via mcp-remote (requires Node.js installed). Edit the configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "paperpop-journals": {
      "command": "npx",
      "args": [
        "-y", "mcp-remote",
        "https://api.byteslink.cn/journals/mcp",
        "--header", "X-API-Key: pp_xxxxxxxx"
      ]
    }
  }
}

After saving, restart Claude Desktop; you should see the two journal tools in the tool list.

Cherry Studio

Settings → MCP Servers → Add Server:

• Type: Streamable HTTP
• URL: https://api.byteslink.cn/journals/mcp
• Header: X-API-Key=pp_xxxxxxxx

Cline / Other Clients Supporting Streamable HTTP

Add to the MCP configuration:

{
  "mcpServers": {
    "paperpop-journals": {
      "type": "streamableHttp",
      "url": "https://api.byteslink.cn/journals/mcp",
      "headers": {
        "X-API-Key": "pp_xxxxxxxx"
      }
    }
  }
}

Field names may vary slightly across clients (e.g. type may be http / streamable-http); refer to your client's documentation. Only two things are essential: the URL and the X-API-Key header.

Errors and Messages

If a tool result contains an error field, its meaning is as follows:

error	Meaning	Suggested Action
missing_api_key	No Key provided	Check the header in your client configuration
invalid_key	Key is invalid	Regenerate it under "User Center → My API" (the old Key is invalidated immediately)
quota_exhausted	Both free and paid quota exhausted	Top up in the User Center
rate_limited	Rate limit triggered	Back off and retry later
too_many	More than 20 journals in a single request	Split into batches (each batch billed once)
upstream_unreachable / upstream_error	Service temporarily unavailable	Retry later; contact us if it persists

Important Notes

• JCR impact factor / quartile data is compiled from publicly available information on the internet, updated to the latest version as of June 17, 2026.
• The warning list is published by the CAS Literature and Information Center (2025 edition, 130+ journals).
• The predatory journal list is published by predatoryjournals.org (2025 edition, ~2800 journals).
• A hit on either list returns is_warning: true; the specific sources are given in sources.
• The MCP service shares the same data, Key, quota, and rate limits as the REST API; results from both are consistent.

FAQ

Q: Should I use MCP or the REST API? Use the REST API for writing code and secondary development (Zotero plugins, automation scripts); use MCP for querying directly within an AI conversation. Both share the same quota and can be used interchangeably.

Q: Can the AI model see my Key? No. The Key only exists in your local client configuration and is sent as a request header to our server — it never enters the conversation content.

Q: What if I lose my plaintext Key? Simply regenerate it under "User Center → My API"; the old Key is invalidated immediately. Remember to update the configuration in each client accordingly.

Related Links

• API Reference — Full description of returned fields (MCP tool return structure matches REST)
• Integration Examples — Zotero plugin, Python, and other code examples
• Try it online