io.github.joegra2003/metamodel
AI-callable calculators and engineering models with real formulas. No hallucinated math.
Open source Repository Open in the app JSON README (API)
About
AI-callable calculators and engineering models with real formulas. No hallucinated math.
Details
- Kind
- MCP servers
- Topic
- No topic detected
- Publisher
- joegra2003
- Origin
- official
- Category
- ferramentas
- Transport
- http
- Version
- 1.2.0
- Last push
- 2026-08-23T05:48:07Z
- Repository state
- ativo
- Language
- JavaScript
- Added
- 2026-08-29 04:00:16
- Updated
- 2026-08-29 04:00:16
- Origin id
io.github.joegra2003/metamodel
README
# MetaModel MCP Server
[](https://www.npmjs.com/package/metamodel-mcp)
[](https://modelcontextprotocol.io)
[](LICENSE)
An [MCP (Model Context Protocol)](https://modelcontextprotocol.io) server that lets AI assistants use MetaModel's formula engine for certified computation. Turn published calculators, pricing tools, and engineering models into AI-callable tools — no hallucinated math.
> **All tools are read-only.** This server fetches published project schemas and runs stateless computations. It never writes, modifies, or stores any data.
## Quick Start
### Remote (hosted) — easiest
No install. Add the URL as a custom connector:
```
https://www.metamodel.app/api/mcp
```
- **Claude.ai / Claude Desktop**: Settings → Connectors → Add custom connector → paste the URL
- **Claude Code**: `claude mcp add --transport http metamodel https://www.metamodel.app/api/mcp`
Works on web and mobile; no Node required. The hosted endpoint is stateless, read-only, and rate-limited.
### Claude Desktop
Add to your Claude Desktop config (`~/Library/Application Support/Claude/claude_desktop_config.json` on macOS):
```json
{
"mcpServers": {
"metamodel": {
"command": "npx",
"args": ["-y", "metamodel-mcp"]
}
}
}
```
### Claude Code
```bash
claude mcp add metamodel -- npx -y metamodel-mcp
```
### Other MCP Clients
Any MCP-compatible client can connect via stdio:
```bash
npx -y metamodel-mcp
```
## Tools
### `metamodel_list_projects`
Browse available calculators and engineering models. Returns project names, descriptions, publish tokens, and model names.
- **Annotations:** `readOnlyHint: true`
### `metamodel_get_schema`
Discover inputs and outputs for a specific project. Returns model names, input parameters (with types, defaults, validation rules), output fields, and formulas.
- **Annotations:** `readOnlyHint: true`
| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `token` | string | Yes | Project publish token (from `metamodel_list_projects`) |
### `metamodel_compute`
Run a computation with input values. Send inputs once — they're auto-routed to the correct model by property name. Outputs from all models are returned, including cross-model cascading.
- **Annotations:** `readOnlyHint: true`
| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `token` | string | Yes | Project publish token |
| `model` | string | No | Target a specific model. When omitted, returns all models (recommended). |
| `inputs` | object | No | Input values as key-value pairs. Auto-routed to the correct model. Omitted inputs use defaults. |
## Examples
### Example 1: List Available Projects
**Prompt:** "What calculators are available on MetaModel?"
**Tool call:** `metamodel_list_projects()`
**Response (truncated):**
```json
{
"projects": [
{
"token": "989bc6ae-e4d7-4585-8908-bfd03358043e",
"name": "Deck Builder",
"description": "Interactive deck builder with code-compliant sizing. Uses LOOKUP tables for beams, frost depths, and railing requirements.",
"models": ["deck", "platformModel", "beamsModel", "postsModel", "railingModel", "summaryModel"]
},
{
"token": "fdc5fbef-9d4b-46c3-b72d-1950e03d4bf4",
"name": "Building Engineer",
"description": "Complete building engineering calculator. Enter room dimensions to auto-size HVAC, electrical, and lighting systems with full cost estimation.",
"models": ["room", "hvac", "electrical", "lighting", "costEstimator"]
},
{
"token": "363c7753-ac4b-4de4-b1e7-e4536cb2f9bb",
"name": "Life Expectancy Calculator",
"description": "Estimate your life expectancy based on age, sex, and lifestyle factors.",
"models": ["basics", "lifestyle", "results"]
}
]
}
```
### Example 2: Get Project Schema
**Prompt:** "What inputs does the Building Engineer calculator need?"
**Tool call:** `metamodel_get_schema({ token: "fdc5fbef-9d4b-46c3-b72d-1950e03d4bf4" })`
**Response (truncated):**
```json
{
"projectName": "Building Engineer",
"models": [
{
"name": "room",
"title": "Room Dimensions",
"inputs": [
{ "name": "length", "type": "number", "defaultValue": 35.26 },
{ "name": "width", "type": "number", "defaultValue": 60 },
{ "name": "height", "type": "number", "defaultValue": 12 }
],
"outputs": [
{ "name": "floorArea", "formula": "floorArea = length * width" },
{ "name": "volume", "formula": "volume = length * width * height" }
]
},
{
"name": "hvac",
"title": "HVAC Sizing",
"inputs": [
{ "name": "climateZone", "defaultValue": "cold" },
{ "name": "btuFactor", "type": "number", "defaultValue": 25 }
],
"outputs": [
{ "name": "btuRequired", "formula": "btuRequired = volume@room * btuFactor" },
{ "name": "tonnage", "formula": "tonnage = btuRequired / 12000" },
{ "name": "annualCost", "formula": "annualCost = tonnage * 120" }
]
}
]
}
```
Note the cross-model references: `volume@room` means "use the `volume` output from the `room` model." MetaModel handles this cascading automatically.
### Example 3: Run a Computation
**Prompt:** "Size the HVAC, electrical, and lighting for a 50×80 ft room with 14 ft ceilings"
**Tool call:** `metamodel_compute({ token: "fdc5fbef-...", inputs: { length: 50, width: 80, height: 14 } })`
**Response:**
```json
{
"models": {
"room": {
"outputs": { "floorArea": 4000, "volume": 56000, "wallArea": 3640 }
},
"hvac": {
"outputs": { "btuRequired": 1400000, "tonnage": 116.7, "annualCost": 14000 }
},
"electrical": {
"outputs": { "outletsNeeded": 304, "totalAmps": 456, "circuitCount": 23 }
},
"lighting": {
"outputs": { "totalLumens": 201240, "fixtureCount": 51, "totalWattage": 2040 }
},
"costEstimator": {
"outputs": {
"hvacMaterial": 415917, "electricalMaterial": 18400,
"lightingMaterial": 7650, "totalLabor": 89321, "grandTotal": 531288
}
}
},
"metadata": { "projectName": "Building Engineer", "evaluationMs": 7.1 }
}
```
One API call → room geometry, HVAC sizing, electrical load, lighting design, and full cost estimate. All computed from real formulas in ~7ms, not LLM-generated.
## Development
To test against a local MetaModel instance:
```bash
# Clone and build
cd packages/mcp-server
npm install
npm run build
# Run with local URL
node dist/index.js --url http://localhost:3000
# Test with MCP Inspector
npx @modelcontextprotocol/inspector node dist/index.js --url http://localhost:3000
```
## Privacy Policy
MetaModel's MCP server is **stateless and read-only**:
- **No authentication required** — all published projects are public
- **No personal data collected** — computations are anonymous
- **No data stored** — inputs are evaluated and discarded immediately
- **No cookies or tracking** — the server makes direct API calls to metamodel.app
- **No third-party data sharing** — results go only to the requesting client
Full privacy policy: [https://www.metamodel.app/privacy](https://www.metamodel.app/privacy)
## About MetaModel
[MetaModel](https://www.metamodel.app) lets you build calculators, pricing tools, and engineering models with a spreadsheet-like formula language. Describe what you want, AI builds it, publish in seconds. Models become API-callable computation endpoints that any AI assistant can use via this MCP server.
## License
MIT
## Troubleshooting
- **"Project not found or not published"** — the token belongs to an unpublished or deleted project. Ask the project owner for a current publish token, or list what's available with `metamodel_list_projects`.
- **Unknown input names** — inputs are matched by property name. Call `metamodel_get_schema` first; it returns the exact input names, types, and defaults for the project.
- **Inputs sent as a JSON string** — pass `inputs` as a JSON object (`{"width": 12}`), not a stringified object. Stringified inputs fail with an "Unknown input" error naming a character index.
- **Rate limits (hosted endpoint)** — the hosted URL is rate-limited per client. For heavy use, run the npm package locally with your own network egress.
- **Node version (local install)** — the stdio server needs Node 18+.