Skip to main content
Glama
samuellawrence

OpenAPI MCP Bridge

OpenAPI MCP Bridge

A generic MCP server that takes any OpenAPI/Swagger specification and exposes it as MCP tools, allowing AI assistants to search, explore, and execute any REST API.

Architecture

                                    +------------------+
                                    |   Claude / AI    |
                                    +--------+---------+
                                             |
                                             | MCP Protocol
                                             v
+------------------------------------------------------------------+
|                      OpenAPI MCP Bridge                          |
|                                                                  |
|  +-------------+    +-------------+    +------------------+      |
|  |   Config    |    |   Parser    |    |    Registry      |      |
|  | (apis.json) |--->| (OpenAPI)   |--->| (API endpoints)  |      |
|  +-------------+    +-------------+    +------------------+      |
|                                                 |                |
|  +-------------+    +-------------+    +--------v---------+      |
|  | Guardrails  |    |   Search    |    |    Executor      |      |
|  | (safety)    |    |  (fuzzy)    |    |    (httpx)       |      |
|  +-------------+    +-------------+    +------------------+      |
|                                                 |                |
+------------------------------------------------------------------+
                                                  |
                                                  v
                                    +------------------+
                                    |    REST APIs     |
                                    | (Petstore, etc)  |
                                    +------------------+

Related MCP server: Swagger MCP

Quick Start

Installation

# Clone the repository
git clone https://github.com/your-username/openapi-mcp-bridge.git
cd openapi-mcp-bridge

# Install with uv
uv sync --all-extras

# Or with pip
pip install -e ".[dev]"

Register an API

Edit config/apis.json to add your API:

{
  "apis": [
    {
      "name": "my-api",
      "spec_url": "https://api.example.com/openapi.json",
      "base_url": "https://api.example.com",
      "auth": {
        "type": "bearer",
        "token": "$MY_API_TOKEN",
        "header_name": "Authorization"
      },
      "settings": {
        "default_page_size": 20,
        "confirm_destructive": true
      }
    }
  ]
}

Xquik API Example

For a real authenticated OpenAPI 3.1 API, copy config/xquik.apis.example.json to your active config and set XQUIK_API_KEY. The example registers Xquik's public spec for X/Twitter automation, trends, tweet search, media, monitor, and webhook endpoints.

Run the Server

# Run with fuzzy search (default)
python -m src.server

# Run with embedding search (better semantic understanding)
python -m src.server --search-provider embedding

# Or set via environment variable
SEARCH_PROVIDER=embedding python -m src.server

Install Embedding Search (Optional)

For better semantic search using sentence-transformers:

# With uv
uv pip install "sentence-transformers>=2.2.0" "numpy>=1.24.0"

# Or with pip
pip install sentence-transformers numpy

Configuration Reference

API Configuration

Field

Type

Required

Description

name

string

Yes

Unique identifier for the API

spec_url

string

Yes

URL or local path to OpenAPI spec

base_url

string

Yes

Base URL for API requests

auth

object

No

Authentication configuration

settings

object

No

API-specific settings

Authentication Types

Type

Description

Example

bearer

Bearer token in Authorization header

Authorization: Bearer <token>

api_key

API key in header or query param

X-API-Key: <token>

basic

Basic auth (base64 encoded)

Authorization: Basic <base64>

none

No authentication

-

Environment variables can be referenced with $VAR_NAME syntax.

Settings

Setting

Default

Description

default_page_size

20

Default limit for list responses

max_batch_size

50

Maximum requests in batch execution

rate_limit_per_second

5

Rate limiting for requests

confirm_destructive

true

Require confirmation for DELETE/PUT/PATCH

Search Providers

Fuzzy Search (Default)

Uses thefuzz library for string matching. Fast and works without additional dependencies.

python -m src.server --search-provider fuzzy

Best for: Exact keyword matching, operation IDs, path names.

Uses sentence-transformers for semantic similarity. Better understanding of synonyms and intent.

python -m src.server --search-provider embedding

Best for: Natural language queries, synonym matching, semantic similarity.

Comparison:

Query

Fuzzy

Embedding

"find all pets"

High confidence

High confidence

"what animals are available"

Low confidence

High confidence

"buy a pet"

Mixed results

Finds store/order

"remove a specific animal"

Mixed results

Finds DELETE pet

Tool Reference

1. list_apis

List all registered OpenAPI/Swagger APIs.

Input: None

Output:

[
  {
    "name": "petstore",
    "base_url": "https://petstore.example.com",
    "description": "Pet Store API",
    "auth_type": "api_key",
    "endpoint_count": 15
  }
]

2. search_endpoints

Search for API endpoints by natural language description.

Input:

{
  "api": "petstore",
  "query": "find all available pets",
  "limit": 5
}

Output:

{
  "api": "petstore",
  "query": "find all available pets",
  "results": [
    {
      "endpoint": {
        "path": "/pet/findByStatus",
        "method": "GET",
        "summary": "Finds Pets by status",
        "parameters": [...]
      },
      "similarity_score": 0.85,
      "low_confidence": false
    }
  ],
  "total_results": 5
}

3. execute_endpoint

Execute an API endpoint.

Input:

{
  "api": "petstore",
  "path": "/pet/{petId}",
  "method": "GET",
  "params": {"petId": 123},
  "limit": 20,
  "offset": 0,
  "confirmed": false
}

Output:

{
  "status_code": 200,
  "data": {"id": 123, "name": "Buddy", "status": "available"},
  "truncated": false,
  "auth_error": false
}

For destructive operations (DELETE, PUT, PATCH), set confirmed: true.

4. batch_execute

Execute multiple API endpoints in parallel.

Input:

{
  "api": "petstore",
  "requests": [
    {"path": "/pet/1", "method": "GET"},
    {"path": "/pet/2", "method": "GET"},
    {"path": "/pet/3", "method": "GET"}
  ],
  "parallel": true,
  "confirmed": true
}

Output:

{
  "results": [...],
  "summary": {"total": 3, "succeeded": 3, "failed": 0}
}

Usage Examples

Example 1: Simple Query

User: What pets are available in the store?

AI: Let me search for that endpoint and get the data.
    1. search_endpoints(api="petstore", query="find available pets")
    2. execute_endpoint(api="petstore", path="/pet/findByStatus",
                        method="GET", params={"status": "available"})

    Result: Found 6 available pets: Buddy (dog), Whiskers (cat), ...

Example 2: Creating a Resource

User: Add a new pet named "Max" to the store.

AI: 1. search_endpoints(api="petstore", query="create new pet")
    2. execute_endpoint(api="petstore", path="/pet", method="POST",
                        body={"name": "Max", "species": "dog", "status": "available"})

    Result: Created pet with ID 15.

Example 3: Destructive Operation

User: Delete pet #15.

AI: 1. execute_endpoint(api="petstore", path="/pet/{petId}", method="DELETE",
                        params={"petId": 15}, confirmed=false)

    Warning: This is a destructive operation. Set confirmed=true to proceed.

User: Yes, go ahead.

AI: 2. execute_endpoint(..., confirmed=true)

    Result: Pet #15 deleted successfully.

Claude Desktop Integration

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "openapi-bridge": {
      "command": "python",
      "args": ["-m", "src.server"],
      "cwd": "/path/to/openapi-mcp-bridge",
      "env": {
        "PETSTORE_KEY": "your-api-key"
      }
    }
  }
}

Claude Code Integration

Create .mcp.json in your project root:

{
  "mcpServers": {
    "openapi-bridge": {
      "command": "python",
      "args": ["-m", "src.server"],
      "cwd": "/path/to/openapi-mcp-bridge",
      "env": {
        "PETSTORE_KEY": "your-api-key"
      }
    }
  }
}

Testing

Run Unit Tests

pytest tests/test_parser.py tests/test_search.py tests/test_executor.py -v

Run Integration Tests

# Requires mock server to start automatically
pytest tests/test_integration.py -v

Start Mock Server Manually

cd mock-petstore
./run.sh

Development

Project Structure

openapi-mcp-bridge/
├── src/
│   ├── __init__.py
│   ├── server.py          # MCP server with 4 tools
│   ├── config.py          # Configuration loader
│   ├── parser.py          # OpenAPI spec parser
│   ├── registry.py        # API registry
│   ├── executor.py        # HTTP request executor
│   ├── guardrails.py      # Safety checks
│   └── search/
│       ├── base.py        # Search interface
│       ├── fuzzy.py       # Fuzzy search
│       └── embedding.py   # Embedding search (placeholder)
├── config/
│   └── apis.json          # API registrations
├── mock-petstore/         # Test server
├── tests/
└── pyproject.toml

License

MIT

A
license - permissive license
-
quality - not tested
C
maintenance

Maintenance

Maintainers
Response time
Release cycle
Releases (12mo)
Commit activity

Resources

Unclaimed servers have limited discoverability.

Looking for Admin?

If you are the server author, to access and configure the admin panel.

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/samuellawrence/openapi-mcp-bridge'

If you have feedback or need assistance with the MCP directory API, please join our Discord server