MCP Hub

Dynamic OpenAPI to MCP server generator. Upload OpenAPI specs and instantly expose them as MCP (Model Context Protocol) servers.

Features

Dynamic MCP Generation: Convert any OpenAPI 3.x spec to an MCP server on-the-fly
Control Plane API: REST API to manage specs (upload, enable, disable, delete)
Multi-spec Support: Run multiple MCP servers simultaneously under /mcp/{spec_name}/
Zero Configuration: Tools are automatically generated from OpenAPI operations

Quick Start

1. Install Dependencies

# Using pip
pip install -e .

# Or install dependencies directly
pip install fastapi uvicorn httpx pyyaml python-multipart pydantic fastmcp

2. Run the Server

uvicorn app.main:app --reload --port 8000

The server starts at http://localhost:8000.

3. Register an OpenAPI Spec

# Upload the HTTPBin example spec
curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=httpbin" \
  -F "file=@examples/httpbin.yaml"

4. Enable MCP Exposure

curl -X POST "http://localhost:8000/specs/httpbin/enable"

5. Connect Your MCP Client

The MCP server is now available at http://localhost:8000/mcp/httpbin/

For MCP clients (e.g., Claude Desktop with HTTP transport):

http://localhost:8000/mcp/httpbin/mcp

API Reference

Control Plane Endpoints

Method	Endpoint	Description
POST	`/specs/upload`	Upload an OpenAPI spec (multipart form)
GET	`/specs`	List all registered specs
GET	`/specs/{name}`	Get spec details and tool names
POST	`/specs/{name}/enable`	Enable MCP exposure
POST	`/specs/{name}/disable`	Disable MCP exposure
DELETE	`/specs/{name}`	Delete a spec
GET	`/health`	Health check

Upload Parameters

name (required): Unique identifier for the spec
file (required): OpenAPI spec file (YAML or JSON)
base_url_override (optional): Override the upstream API base URL

MCP Data Plane

Once a spec is enabled, its MCP server is available at:

/mcp/{spec_name}/

Tool Generation

Tools are generated from OpenAPI operations with these rules:

Tool Naming

Uses operationId if present in the spec
Otherwise: METHOD__sanitized_path (e.g., GET__pets_petId)

Tool Inputs

Path parameters → required fields
Query parameters → optional fields (unless required: true)
JSON request body → body field (dict type)

Tool Outputs

JSON responses are returned as-is
Non-JSON responses return {"text": "...", "status_code": ..., "content_type": "..."}

Examples

Register and Enable Dog API

# Upload
curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=dog" \
  -F "file=@examples/dog_api.yaml"

# Enable
curl -X POST "http://localhost:8000/specs/dog/enable"

# List tools
curl "http://localhost:8000/specs/dog"

Register and Enable DailyMed (Drug Labeling API)

Access FDA drug labeling information from the National Library of Medicine's DailyMed database:

# Upload
curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=dailymed" \
  -F "file=@examples/dailymed.yaml"

# Enable
curl -X POST "http://localhost:8000/specs/dailymed/enable"

# List tools
curl "http://localhost:8000/specs/dailymed"

Available DailyMed Tools:

dailymed_listSpls - Search drug labeling documents by name, NDC, or RxCUI
dailymed_getSplBySetId - Get full details of a specific drug label
dailymed_getSplHistory - Get version history of a drug label
dailymed_getSplMedia - Get associated images and PDFs
dailymed_getSplNdcs - Get NDCs for a drug label
dailymed_getSplPackaging - Get packaging information
dailymed_listDrugNames - Search for drug names
dailymed_listNdcs - List National Drug Codes
dailymed_listRxcuis - List RxNorm identifiers

Example Tool Calls:

# Search for aspirin SPLs
dailymed_listSpls drug_name="aspirin" name_type="BOTH" pagesize=5

# Get details for a specific SPL
dailymed_getSplBySetId setid="b0aec776-3e30-4e59-8a07-0027e5fc4cb3"

# Search drug names
dailymed_listDrugNames drug_name="ibuprofen" pagesize=10

Register and Enable openFDA Drug Label API

Query FDA drug product labeling data including prescribing information, warnings, and drug interactions:

# Upload
curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=openfda" \
  -F "file=@examples/openfda_drug_label.yaml"

# Enable
curl -X POST "http://localhost:8000/specs/openfda/enable"

Available Tool:

openfda_drug_label_query - Search FDA drug labeling with openFDA query syntax

Example Tool Calls:

# Search by brand name
openfda_drug_label_query search="openfda.brand_name:advil" limit=5

# Search drug interactions
openfda_drug_label_query search="drug_interactions:warfarin" limit=10

# Search by RxCUI
openfda_drug_label_query search="openfda.rxcui:198440"

# Count manufacturers
openfda_drug_label_query count="openfda.manufacturer_name.exact"

Register and Enable RxNorm API

Access NLM's RxNorm database for normalized drug names and identifiers:

# Upload
curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=rxnorm" \
  -F "file=@examples/rxnorm.yaml"

# Enable
curl -X POST "http://localhost:8000/specs/rxnorm/enable"

Key RxNorm Tools:

rxnorm_findRxcui - Find RxCUI by drug name or external ID
rxnorm_getRxConceptProperties - Get concept properties
rxnorm_getRelatedByType - Find related concepts by TTY or RELA
rxnorm_getDrugs - Search drugs by name
rxnorm_getNdcs - Get NDCs for an RxCUI
rxnorm_getInteraction - Get drug-drug interactions
rxnorm_getInteractionList - Check interactions between multiple drugs
rxnorm_getApproximateMatch - Fuzzy match drug names

Example Tool Calls:

# Find RxCUI by drug name
rxnorm_findRxcui name="lipitor"

# Get concept properties
rxnorm_getRxConceptProperties rxcui="198440"

# Find related concepts (ingredients)
rxnorm_getRelatedByType rxcui="198440" tty="IN"

# Check drug interactions
rxnorm_getInteraction rxcui="198440"

# Check interactions between multiple drugs
rxnorm_getInteractionList rxcuis="198440,153165"

With Base URL Override

curl -X POST "http://localhost:8000/specs/upload" \
  -F "name=myapi" \
  -F "file=@myspec.yaml" \
  -F "base_url_override=https://api.example.com/v1"

Claude Desktop Configuration

Add to your Claude Desktop MCP config:

{
  "mcpServers": {
    "httpbin": {
      "url": "http://localhost:8000/mcp/httpbin/mcp"
    },
    "dog": {
      "url": "http://localhost:8000/mcp/dog/mcp"
    }
  }
}

Architecture

┌─────────────────────────────────────────────────────────────┐
│                        MCP Hub                               │
├─────────────────────────────────────────────────────────────┤
│  Control Plane (/specs/*)     │    Data Plane (/mcp/*)      │
│  ┌─────────────────────────┐  │  ┌─────────────────────────┐│
│  │ POST /specs/upload      │  │  │   MCPDispatcher         ││
│  │ GET  /specs             │  │  │   ┌─────────────────┐   ││
│  │ GET  /specs/{name}      │  │  │   │ /mcp/httpbin/   │───┼┼──► HTTPBin API
│  │ POST /specs/{name}/enable│ │  │   │ /mcp/dog/      │───┼┼──► Dog API
│  │ POST /specs/{name}/disable│ │ │   │ /mcp/{spec}/    │───┼┼──► Any API
│  │ DELETE /specs/{name}    │  │  │   └─────────────────┘   ││
│  └─────────────────────────┘  │  └─────────────────────────┘│
│              │                │              │               │
│              ▼                │              ▼               │
│  ┌─────────────────────────────────────────────────────────┐│
│  │                    SpecRegistry                          ││
│  │   - Stores spec metadata & parsed content               ││
│  │   - Manages enable/disable state                        ││
│  │   - Holds generated FastMCP http_app instances          ││
│  └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘

Limitations (MVP)

In-memory storage: Specs are lost on restart
No authentication: Auth headers are not forwarded to upstream APIs
JSON bodies only: Only application/json request bodies are supported
OpenAPI 3.x only: Swagger 2.0 specs are not supported

Project Structure

mcp_hub/
├── app/
│   ├── __init__.py
│   ├── main.py           # FastAPI app, routes, MCP mount
│   ├── models.py         # Pydantic models
│   ├── registry.py       # In-memory spec registry
│   ├── openapi_loader.py # YAML/JSON parsing & validation
│   ├── openapi_to_mcp.py # OpenAPI → FastMCP conversion
│   └── mcp_dispatcher.py # ASGI dispatcher for /mcp/*
├── examples/
│   ├── httpbin.yaml      # HTTPBin OpenAPI spec
│   ├── dog_api.yaml      # Dog API OpenAPI spec
│   ├── dailymed.yaml     # DailyMed drug labeling API spec
│   ├── openfda_drug_label.yaml  # openFDA drug label API spec
│   ├── rxnorm.yaml       # RxNorm drug identifiers API spec
│   └── demo.md           # Demo walkthrough
├── pyproject.toml
└── README.md

MCP Hub

MCP Hub

Features

Quick Start

1. Install Dependencies

2. Run the Server

3. Register an OpenAPI Spec

4. Enable MCP Exposure

5. Connect Your MCP Client

API Reference

Control Plane Endpoints

Upload Parameters

MCP Data Plane

Tool Generation

Tool Naming

Tool Inputs

Tool Outputs

Examples

Register and Enable Dog API

Register and Enable DailyMed (Drug Labeling API)

Register and Enable openFDA Drug Label API

Register and Enable RxNorm API

With Base URL Override

Claude Desktop Configuration

Architecture

Limitations (MVP)

Project Structure

Latest Blog Posts

MCP directory API