Crystallography

mcp-crystallography

Crystallography Open Database (COD) MCP.

Part of Pipeworx — an MCP gateway connecting AI agents to 1875+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

Tool	Description
search_structures	Search the Crystallography Open Database (COD), an open repository of crystal structures (inorganic, organic, metal-organic, and mineral). Search by compound name (free text), chemical formula, or mineral name; returns matching crystal structures with unit-cell parameters, space group, year, and a link to the CIF structure file. Keyless. Provide at least one of query, formula, or mineral. Formulas are normalized to COD's stored Hill notation for you, so "NaCl", "SiO2" and "CaCO3" all work; the response reports formula_searched with the exact string that was matched.
get_structure	Look up a single crystal structure in the Crystallography Open Database (COD) by its numeric COD ID (e.g. "1009000"). Returns the compound/mineral name, chemical formula, space group, full unit-cell parameters (a, b, c, alpha, beta, gamma, volume), bibliographic details (title, authors, journal, year, DOI), and a link to the CIF structure file. Keyless.
get_cif	Fetch the full CIF (Crystallographic Information File) for a COD structure by its numeric COD ID — the actual machine-readable structure: symmetry operations and the atom sites (element, fractional x/y/z coordinates, occupancy). Use after search_structures/get_structure when you need the real atomic structure, not just the metadata/link. Returns the CIF text plus a parsed summary (formula, space group, cell, atom count). Keyless.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "crystallography": {
      "url": "https://gateway.pipeworx.io/crystallography/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/crystallography/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1875+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/search_structures \
  -H 'Content-Type: application/json' \
  -d '{"query":"quartz"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/search_structures. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

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

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-crystallography

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Crystallography data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT