MCP Zotero

Note: This is an unofficial community project and is not affiliated with, endorsed by, or supported by the Zotero team or the Corporation for Digital Scholarship. "Zotero" is a registered trademark of the Corporation for Digital Scholarship.

A Model Context Protocol server for Zotero integration. It gives any LLM full access to your Zotero library: search, organize, add papers by DOI, import PDFs, read full-text content, and inject live citations into Word documents.

Originally based on mcp-zotero by Abhishek Kalia. This project has since been extensively rewritten with a new architecture, 15 tools (up from 5), citation injection, PDF management, and Claude skill support.

How it works

The server is designed to be usable by any LLM without external documentation. On connection, it sends workflow instructions via the MCP instructions field, and each tool description includes cross-references and usage guidance. An LLM that has never seen this server before can discover the full workflow — from adding papers to producing a cited Word document — directly from the tool listing.

For advanced use cases (PDF upload policy, citation style guidance, source transparency), a Claude skill is included for Claude.ai Projects. But the skill is optional: the MCP server is fully self-documenting.

Local vs Remote LLMs

| Scenario | MCP server | Skill needed? | |---|---|---| | LLM with filesystem access (Claude Code, LM Studio, etc.) | All 15 tools | No | | LLM without filesystem access (Claude.ai Projects, Claude Desktop) | API tools (search, add, metadata) | Yes, for citation injection |

LLMs with filesystem access can use all tools directly, including inject_citations which reads and writes .docx files on disk.

LLMs without filesystem access — including Claude Desktop, which connects to MCP but cannot generate files locally — can use the included Claude skill (skills/zotero-skill-mcp-integrations/), which runs citation injection entirely inside a sandbox. MCP tools handle all Zotero API operations; the skill handles document assembly.

Claude Skill Setup (for Claude.ai Projects and Claude Desktop)

1. Download the skill .zip from the latest GitHub Release
2. Extract it and upload the folder to your Claude.ai Project as a skill
3. The skill enables citation injection directly inside the sandbox, without requiring local filesystem access

Setup

1. Get your Zotero credentials:

   # Create an API key at https://www.zotero.org/settings/keys
   # (enable library read/write + file access)
   # Then retrieve your user ID:
   curl -H "Zotero-API-Key: YOUR_API_KEY" https://api.zotero.org/keys/current

2. Set environment variables:

   export ZOTERO_API_KEY="your-api-key"
   export ZOTERO_USER_ID="user-id-from-curl"
   export UNPAYWALL_EMAIL="[email protected]"   # Optional: enables OA PDF lookup via Unpaywall
   export UNSAFE_OPERATIONS="none"           # Optional: "none" | "items" | "all" (see below)

Environment Variables

| Variable | Required | Description | |---|---|---| | ZOTERO_API_KEY | Yes | API key for Zotero Web API v3. Create one at zotero.org/settings/keys with library read/write and file access permissions. | | ZOTERO_USER_ID | Yes | Your Zotero numeric user ID. Retrieve it with curl -H "Zotero-API-Key: KEY" https://api.zotero.org/keys/current. | | UNPAYWALL_EMAIL | No | Email for Unpaywall API requests (rate-limit policy). Enables OA PDF lookup in add_items_by_doi and find_and_attach_pdfs. If not set, OA PDF features are silently skipped. | | UNSAFE_OPERATIONS | No | Controls destructive operations (deletion). See Unsafe Operations below. Default: none (all deletions blocked). |

Unsafe Operations

By default, the MCP server does not allow any deletion. This is a safety measure to prevent an LLM from accidentally deleting items or collections from your library.

To enable deletion, set the UNSAFE_OPERATIONS environment variable to one of the following values:

| Value | delete_items | delete_collection | Use case | |---|---|---|---| | none (default) | Blocked | Blocked | Safe mode — no deletions possible | | items | Allowed | Blocked | Allow deleting items but protect collection structure | | all | Allowed | Allowed | Full access — items and collections can be deleted |

Important notes:

• If UNSAFE_OPERATIONS is not set, empty, or set to an unrecognized value, it defaults to none.
• The value is case-insensitive (e.g. ALL, Items, NONE all work).
• delete_items moves items to the Zotero trash (recoverable from the Zotero desktop client).
• delete_collection removes the collection (folder) only — items inside it are not deleted and remain in your library.
• The all value includes both item and collection deletion because managing collections inherently requires item-level access.

Configuration example:

{
  "mcpServers": {
    "zotero": {
      "command": "npx",
      "args": ["-y", "@xevos117/mcp-zotero"],
      "env": {
        "ZOTERO_API_KEY": "YOUR_API_KEY",
        "ZOTERO_USER_ID": "YOUR_USER_ID",
        "UNSAFE_OPERATIONS": "items"
      }
    }
  }
}

Integration with Claude Desktop

Add to your Claude Desktop configuration:

{
  "mcpServers": {
    "zotero": {
      "command": "npx",
      "args": ["-y", "@xevos117/mcp-zotero"],
      "env": {
        "ZOTERO_API_KEY": "YOUR_API_KEY",
        "ZOTERO_USER_ID": "YOUR_USER_ID",
        "UNPAYWALL_EMAIL": "YOUR_EMAIL"
      }
    }
  }
}

Integration with Claude Code

claude mcp add-json "zotero" '{"command":"npx","args":["tsx","src/server.ts"],"env":{"ZOTERO_API_KEY":"...","ZOTERO_USER_ID":"..."}}'

Available Tools

Library browsing

| Tool | Description | |---|---| | get_collections | List all collections (folders) with keys, names, and parent relationships | | get_collection_items | Get items in a specific collection with keys, titles, authors, dates | | search_library | Search by query, or list items sorted by field (date, title, etc.) | | get_items_details | Batch metadata retrieval for multiple items — returns all type-specific fields (bookTitle, proceedingsTitle, university, etc.) | | get_item_fulltext | Get full-text content of a PDF attachment via Zotero's fulltext index |

Adding content

| Tool | Description | |---|---| | add_items_by_doi | Add papers by DOI with automatic metadata resolution. Auto-attaches OA PDFs via Unpaywall | | add_items | Add items with direct metadata — supports all 37 Zotero item types (books, theses, reports, etc.), batch-capable | | create_collection | Create a new collection, optionally nested under a parent | | import_pdf_to_zotero | Download a PDF from URL, upload to Zotero storage, auto-index full text | | find_and_attach_pdfs | Batch OA PDF lookup and auto-attach via Unpaywall (by item keys or collection) | | add_linked_url_attachment | Attach a URL to an existing item or create a standalone link |

Deleting content

| Tool | Description | |---|---| | delete_items | Delete up to 50 items per call (moves to Zotero trash). Requires UNSAFE_OPERATIONS=items or all | | delete_collection | Delete a collection (folder). Items inside are kept. Requires UNSAFE_OPERATIONS=all |

Citation & documents

| Tool | Description | |---|---| | inject_citations | Inject live Zotero citations into a Word document. Supports APA, IEEE, Vancouver, Harvard, Chicago. Output is saved in the same folder as the input file with a _cited suffix (e.g. paper.docx → paper_cited.docx) | | get_user_id | Returns the configured Zotero user ID |

Development

npm install
npm run build          # Compile TypeScript
npm test               # Run tests (vitest, 404 tests)
npx tsx src/server.ts  # Run directly without building

Debug with MCP Inspector

npx @modelcontextprotocol/inspector npx tsx src/server.ts

License

MIT - see LICENSE for details.