mcphub/docs/api-reference/openapi.mdx

---
title: "OpenAPI Integration"
description: "Generate OpenAPI specifications from MCP tools for seamless integration with OpenWebUI and other systems"
---

# OpenAPI Generation for OpenWebUI Integration

MCPHub now supports generating OpenAPI 3.0.3 specifications from MCP tools, enabling seamless integration with OpenWebUI and other OpenAPI-compatible systems without requiring MCPO as an intermediary proxy.

## Features

- ✅ **Automatic OpenAPI Generation**: Converts MCP tools to OpenAPI 3.0.3 specification
- ✅ **OpenWebUI Compatible**: Direct integration without MCPO proxy
- ✅ **Real-time Tool Discovery**: Dynamically includes tools from connected MCP servers
- ✅ **Dual Parameter Support**: Supports both GET (query params) and POST (JSON body) for tool execution
- ✅ **No Authentication Required**: OpenAPI endpoints are public for easy integration
- ✅ **Comprehensive Metadata**: Full OpenAPI specification with proper schemas and documentation

## API Endpoints

### OpenAPI Specification

<CodeGroup>

```bash GET /api/openapi.json
curl "http://localhost:3000/api/openapi.json"
```

```bash With Parameters
curl "http://localhost:3000/api/openapi.json?title=My MCP API&version=2.0.0"
```

</CodeGroup>

Generates and returns the complete OpenAPI 3.0.3 specification for all connected MCP tools.

**Query Parameters:**

<ParamField query="title" type="string" optional>
  Custom API title
</ParamField>

<ParamField query="description" type="string" optional>
  Custom API description
</ParamField>

<ParamField query="version" type="string" optional>
  Custom API version
</ParamField>

<ParamField query="serverUrl" type="string" optional>
  Custom server URL
</ParamField>

<ParamField query="includeDisabled" type="boolean" optional default="false">
  Include disabled tools
</ParamField>

<ParamField query="servers" type="string" optional>
  Comma-separated list of server names to include
</ParamField>

### Available Servers

<CodeGroup>

```bash GET /api/openapi/servers
curl "http://localhost:3000/api/openapi/servers"
```

</CodeGroup>

Returns a list of connected MCP server names.

<ResponseExample>

```json Example Response
{
  "success": true,
  "data": ["amap", "playwright", "slack"]
}
```

</ResponseExample>

### Tool Statistics

<CodeGroup>

```bash GET /api/openapi/stats
curl "http://localhost:3000/api/openapi/stats"
```

</CodeGroup>

Returns statistics about available tools and servers.

<ResponseExample>

```json Example Response
{
  "success": true,
  "data": {
    "totalServers": 3,
    "totalTools": 41,
    "serverBreakdown": [
      {"name": "amap", "toolCount": 12, "status": "connected"},
      {"name": "playwright", "toolCount": 21, "status": "connected"},
      {"name": "slack", "toolCount": 8, "status": "connected"}
    ]
  }
}
```

</ResponseExample>

### Tool Execution

<CodeGroup>

```bash GET /api/tools/{serverName}/{toolName}
curl "http://localhost:3000/api/tools/amap/amap-maps_weather?city=Beijing"
```

```bash POST /api/tools/{serverName}/{toolName}
curl -X POST "http://localhost:3000/api/tools/playwright/playwright-browser_navigate" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com"}'
```

</CodeGroup>

Execute MCP tools via OpenAPI-compatible endpoints.

**Path Parameters:**

<ParamField path="serverName" type="string" required>
  The name of the MCP server
</ParamField>

<ParamField path="toolName" type="string" required>
  The name of the tool to execute
</ParamField>

## OpenWebUI Integration

To integrate MCPHub with OpenWebUI:

<Steps>
  <Step title="Start MCPHub">
    Ensure MCPHub is running with your MCP servers configured
  </Step>
  <Step title="Get OpenAPI Specification">
    ```bash
    curl http://localhost:3000/api/openapi.json > mcphub-api.json
    ```
  </Step>
  <Step title="Add to OpenWebUI">
    Import the OpenAPI specification file or point to the URL directly in OpenWebUI
  </Step>
</Steps>

### Configuration Example

In OpenWebUI, you can add MCPHub as an OpenAPI tool by using:

<CardGroup cols={2}>
  <Card title="OpenAPI URL" icon="link">
    `http://localhost:3000/api/openapi.json`
  </Card>
  <Card title="Base URL" icon="server">
    `http://localhost:3000/api`
  </Card>
</CardGroup>

## Generated OpenAPI Structure

The generated OpenAPI specification includes:

### Tool Conversion Logic

- **Simple tools** (≤10 primitive parameters) → GET endpoints with query parameters
- **Complex tools** (objects, arrays, or >10 parameters) → POST endpoints with JSON request body
- **All tools** include comprehensive response schemas and error handling

### Example Generated Operation

```yaml
/tools/amap/amap-maps_weather:
  get:
    summary: "根据城市名称或者标准adcode查询指定城市的天气"
    operationId: "amap_amap-maps_weather"
    tags: ["amap"]
    parameters:
      - name: city
        in: query
        required: true
        description: "城市名称或者adcode"
        schema:
          type: string
    responses:
      '200':
        description: "Successful tool execution"
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ToolResponse'
```

### Security

- Bearer authentication is defined but not enforced for tool execution endpoints
- Enables flexible integration with various OpenAPI-compatible systems

## Benefits over MCPO

<CardGroup cols={2}>
  <Card title="Direct Integration" icon="plug">
    No need for intermediate proxy
  </Card>
  <Card title="Real-time Updates" icon="refresh">
    OpenAPI spec updates automatically as MCP servers connect/disconnect
  </Card>
  <Card title="Better Performance" icon="bolt">
    Direct tool execution without proxy overhead
  </Card>
  <Card title="Simplified Architecture" icon="layer-group">
    One less component to manage
  </Card>
</CardGroup>

## Troubleshooting

<AccordionGroup>
  <Accordion title="OpenAPI spec shows no tools">
    Ensure MCP servers are connected. Check `/api/openapi/stats` for server status.
  </Accordion>
  
  <Accordion title="Tool execution fails">
    Verify the tool name and parameters match the OpenAPI specification. Check server logs for details.
  </Accordion>
  
  <Accordion title="OpenWebUI can't connect">
    Ensure MCPHub is accessible from OpenWebUI and the OpenAPI URL is correct.
  </Accordion>
  
  <Accordion title="Missing tools in specification">
    Check if tools are enabled in your MCP server configuration. Use `includeDisabled=true` to see all tools.
  </Accordion>
</AccordionGroup>