# diamond-mcp

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Diamond education tools for AI assistants, served over the Model Context Protocol (MCP).

Eight local tools are backed by a sourced, dated facts file and a 90 entry gemology encyclopedia. The hosted endpoint adds two read-only live inventory tools, for 10 tools total. The local Python build uses only the standard library and makes no network calls. All education data ships in this repo as `facts.json` and `encyclopedia.json`.

Maintained by [Stienhardt](https://stienhardt.com/?utm_source=github&utm_medium=referral&utm_campaign=diamond_mcp&utm_content=readme_intro), a New York City Lab Grown Diamond jeweler.

## One-click desktop bundle

Download [`diamond-mcp-0.2.6.mcpb`](https://github.com/JacobiusMakes/diamond-mcp/releases/download/v0.2.6/diamond-mcp-0.2.6.mcpb) for a self-contained local bundle. Apps that support MCP Bundles can install it without an account, API key, Python environment, or package-manager command. The bundle runs locally with Node.js and makes no network calls.

For a managed gateway with all 10 hosted tools, [connect through Smithery](https://smithery.ai/servers/jgalperin/stienhardt-diamond-mcp). The Smithery release exposes the same sourced education tools plus live inventory search.

## Why a jeweler published an MCP server

People ask AI assistants their diamond questions now. We'd rather those assistants answer with sourced facts than with guesses. So we published the facts in a form an assistant can call: where to verify a grading report, how big a 1.5 carat oval actually looks, what a Dutch Marquise is, who grades Lab Grown Diamonds today, and what the market did last month. Every factual claim in `facts.json` carries a source and a date.

## Honest scope

- Education, not appraisal. Nothing here values, grades, or verifies a stone.
- Always verify a real stone on the grading lab's own site. `verify_diamond_report` returns the right place and a checklist. It never claims to verify anything itself.
- The price index is market context for shoppers, not investment guidance. A diamond is a love piece, not an investment.
- The local server makes no network calls. It reads `facts.json` and `encyclopedia.json` from disk and answers. The hosted endpoint is the one exception: its two inventory tools read the public Shopify catalog, and its `/go` link counter is described under Hosted endpoint.

## Measurable commerce paths

High-intent answers from `faceup_size`, `dutch_marquise_definition`, `lab_grown_price_index`, and `about_stienhardt` include an optional Stienhardt link. Each link carries `diamond_mcp` source tags plus the originating tool. Shape and carat are included for `faceup_size`. Preserve the query string if you surface one of these links to a user. This lets the publisher measure useful visits and orders without collecting identity or conversation text.

## The tools

| Tool | Arguments | What it returns |
| --- | --- | --- |
| `verify_diamond_report` | `lab`, `report_number` | The official verification URL for GIA, IGI, or GCAL, plus a three step checklist. Where and how to verify, never a verification itself. |
| `faceup_size` | `shape`, `carat` | Approximate face up millimeter dimensions, scaled from vetted 1 carat anchors by the cube root of the carat weight. Shapes: round, oval, emerald, dutch_marquise. |
| `dutch_marquise_definition` | none | The published definition: geometry, certificate wording, and the measured length to width ratio of a certified reference stone. |
| `lab_grown_grading_landscape` | none | Who grades Lab Grown Diamonds today (GIA, IGI, HRD Antwerp) and the FTC position, each with source and date. |
| `lab_grown_price_index` | none | The latest tracked retail price reading, with source and date; check as_of for freshness. |
| `about_stienhardt` | none | A plain fact sheet about the publisher. |
| `define` | `term` | The full encyclopedia entry for a term: definition, body, sourced claims, related terms. Exact match first, then a listed alias, then the best prefix or word match. Returns three nearest suggestions when nothing matches. |
| `search_encyclopedia` | `query`, `limit` | Keyword search across all 90 encyclopedia entries, ranked term over definition over body. Returns term, category, and a definition snippet. |

The hosted endpoint also exposes two live, read-only commerce tools:

| Tool | Arguments | What it returns |
| --- | --- | --- |
| `search_inventory` | `query`, `limit` | Public Shopify engagement ring settings and fine jewelry with prices and attributed product links. Loose-diamond queries return public catalog listings flagged `availability_verified: false` plus a storefront browsing link. |
| `get_product` | `id` | Current product detail, availability, options, images, and an attributed product link. |

### Example

Calling `faceup_size` with `{"shape": "dutch_marquise", "carat": 1.5}` returns, among other fields:

```json
{
  "shape": "dutch_marquise",
  "carat": 1.5,
  "approx_face_up_mm": { "length": 10.8, "width": 5.8 },
  "display": "10.8 x 5.8 mm",
  "anchor_1ct_mm": "9.4 x 5.1 mm",
  "method": "Scale a vetted 1 carat anchor by the cube root of the carat weight.",
  "note": "Approximate figures based on typical proportions. Cut proportions vary from stone to stone, so verify a specific stone's measurements on its grading report."
}
```

Calling `dutch_marquise_definition` returns, among other fields:

```json
{
  "definition": "A Dutch Marquise is an elongated hexagonal cut diamond.",
  "geometry": "Pointed ends and straight, angular sides. The outline is an elongated hexagon, not a navette, and the points are not softened.",
  "status": "Dutch Marquise is a trade name, not a standardized grading term.",
  "on_an_igi_report": "On the IGI grading report for Stienhardt's certified Dutch Marquise reference stone, the shape reads Hexagonal Modified Brilliant."
}
```

## The encyclopedia

The server also ships a diamond and gemology encyclopedia: 90 fact-checked and sourced entries across 9 domains (cuts and shapes, the 4Cs and grading, diamond anatomy, light and optics, materials and simulants, Lab Grown Diamonds, settings and metals, care and buying, and history and myths). Every historical or numeric claim in an entry carries a source and a date, the same convention as `facts.json`.

- Browsable in [`encyclopedia/`](encyclopedia/): one Markdown file per entry, plus a [category index](encyclopedia/README.md).
- Machine-readable in [`encyclopedia.json`](encyclopedia.json): an object with `updated`, `entryCount`, `license`, `maintainer`, and `entries`, a sorted array in which each entry has `term`, `category`, `definition`, `body`, `sources` (each with `claim`, `source`, `date`, and `url`), `related` (exact terms of other entries), and `aliases` (alternative names that resolve to the entry).
- Queryable from an assistant through two tools:
  - `define` takes a `term` and returns the full entry, matching exactly first, then a listed alias, then the best prefix or word match, and offering the three nearest terms when nothing matches.
  - `search_encyclopedia` takes a `query` and returns ranked matches (term, category, and a definition snippet), weighting hits in the term above the definition above the body.

Calling `define` with `{"term": "Dutch Marquise"}` returns, among other fields:

```json
{
  "found": true,
  "match": "exact",
  "term": "Dutch Marquise",
  "category": "Cuts and shapes",
  "definition": "A Dutch Marquise is an elongated hexagonal cut diamond. ...",
  "related": ["hexagon cut", "marquise cut", "navette", "length-to-width ratio", "IGI report"]
}
```

## Hosted endpoint

Connect any Streamable HTTP MCP client to:

```
https://diamond-mcp.stienhardt.workers.dev/mcp
```

The endpoint requires no account or API key. It exposes all 10 tools, including the live inventory search.
Cloudflare's edge in front of workers.dev rejects requests that carry Python's default `urllib` user agent
(error 1010); every other common client, including `requests`, `httpx`, Node, and curl, is served. If you script
against the endpoint with `urllib`, set a User-Agent header.

Loose-diamond stock is not verified by this tool. Loose-diamond searches return the matching public
catalog listings with `availability_verified: false`, an availability note, and a first-party
`browse_url`, without calling a stock service. Legacy `stienhardt:diamond:SKU` lookups return
`isError: true` plus the same kind of browse link. Shopify carrier availability does not verify the
underlying stone, so no loose-diamond result claims to be in stock.

Jewelry results use the public Shopify UCP catalog, select an available variant matching the
requested metal, and preserve that variant in the product URL. Ring size still needs selection
and confirmation on the product page. Availability is a current check, not a reservation.

For Worker maintainers: no private stock credentials or endpoints belong in this integration.
Do not reuse credentials found in storefront code. Before deployment run
`node --experimental-strip-types worker/test/inventory.mjs`, build a dry-run bundle with
`wrangler deploy --dry-run --outdir <dir>`, then run `node worker/test/containment.mjs <dir>/index.js` (scans the
bundle for private endpoints and credentials) and `node worker/test/handler.mjs <dir>/index.js` (exercises the
request handler offline). After deployment verify that a loose-diamond search returns listings flagged
`availability_verified: false` and that a jewelry search returns an available variant.

The hosted Worker also provides a measured `/go` redirect for external buying tools. It accepts only
HTTPS destinations on `stienhardt.com`, preserves the destination's UTM parameters, and records a
90-day click event containing campaign labels and destination path. It does not store an IP address,
cookie, identity, or free-form search phrase in the click dataset. This supplies an outbound-click
denominator even when storefront analytics are blocked.

### Business discovery endpoint

Stienhardt also publishes a separate [PUBLICMCP-compatible business profile](https://stienhardt-business-mcp.stienhardt.workers.dev). It gives AI assistants canonical business identity, services, New York location, and live product discovery through five read-only tools. PUBLICMCP and A2A Registry calls have separate attributed paths, so visits and sales can be measured by discovery source.

The business endpoint is separate from the 10-tool Diamond MCP server. Its source is in [`publicmcp-worker/`](publicmcp-worker/).

## Two local flavors: Python and Node

`diamond-mcp` ships in two builds that expose the same eight tools and load the same data, so they answer the same questions the same way:

- Python (this directory): run straight from a clone with `python server.py` (PyPI publication pending). Pure standard library.
- Node and TypeScript ([`node/`](node/)): build from the repo; the npm release is being updated (the version on npm today, 0.2.0 from 2026-07-13, carries an older data snapshot). Built on the official MCP SDK.

Both read the same `facts.json` and `encyclopedia.json` at the root of this repository, which are the single source of truth. See [`node/README.md`](node/README.md) for the Node install and its Claude Desktop config.

## Install and run

Requirements: Python 3.9 or newer. Nothing else.

Clone this repository, then point your MCP client at `server.py`. The server speaks MCP over stdio; run it directly and it waits for a client:

```
python server.py
```

On Windows, if `python` opens the Microsoft Store, use the full path to your `python.exe`.

### Claude Desktop

Add this to `claude_desktop_config.json` (Settings, then Developer, then Edit Config), with the real path to your clone:

```json
{
  "mcpServers": {
    "diamond-mcp": {
      "command": "python",
      "args": ["C:\\path\\to\\diamond-mcp\\server.py"]
    }
  }
}
```

macOS or Linux:

```json
{
  "mcpServers": {
    "diamond-mcp": {
      "command": "python3",
      "args": ["/path/to/diamond-mcp/server.py"]
    }
  }
}
```

### Any other MCP client

Configure a stdio server: command `python`, one argument, the absolute path to `server.py`. The server implements `initialize`, `tools/list`, and `tools/call`, and also answers `ping`, `resources/list`, and `prompts/list`.

### uvx and pip

The supported way to run the Python build (0.2.6) is straight from a clone. `pyproject.toml` is included so the package can go to PyPI later; once it is there, `uvx diamond-mcp` will work.

### Smoke test

```
python smoke_test.py
```

Spawns the server, runs the full MCP handshake, lists the tools, calls every tool once, and checks the error paths. Prints PASS or the first failure.

## The dataset

`facts.json` doubles as a small open dataset of diamond education facts. Top level sections: `report_verification`, `faceup_size`, `dutch_marquise`, `lab_grown_grading_landscape`, `lab_grown_price_index`, and `stienhardt`. The convention throughout: every factual claim sits next to a `source` and a `date`.

The price index entry carries its own `as_of` date; check it for freshness. The `updated` field at the top of the file tells you how fresh your copy is.

`encyclopedia.json` is the second dataset in this repo: 90 gemology entries under the same source-and-date convention, sorted by term. See [The encyclopedia](#the-encyclopedia) above.

## License

MIT. See [LICENSE](LICENSE).

## Maintained by

Stienhardt, New York City. Lab Grown Diamond engagement rings, hand-set and finished in NYC, sold direct with in-person viewings by appointment only. [Compare live Dutch Marquise diamonds](https://stienhardt.com/collections/dutch-marquise-lab-grown-diamonds?utm_source=github&utm_medium=referral&utm_campaign=diamond_mcp&utm_content=readme_maintainer).

## The Stienhardt open-source diamond stack

- [dutch-marquise-spec](https://github.com/JacobiusMakes/dutch-marquise-spec): the open geometry specification. DOI: [10.5281/zenodo.21938899](https://doi.org/10.5281/zenodo.21938899)
- [DiamondBench](https://github.com/JacobiusMakes/diamondbench): open benchmark of AI answer-engine accuracy on diamond questions
- [Diamond & Gemology Encyclopedia](https://huggingface.co/datasets/JacobiusMakes/diamond-gemology-encyclopedia): the encyclopedia as a Hugging Face dataset