openmcp-core

Core domain types for Model Context Protocol (MCP) tool generation.

MCP 2025 Support

This package includes full MCP 2025 Phase 1 compliance:

• JSON Schema 2020-12: Typed JSON Schema definitions with 2020-12 dialect
• Tool Naming: MCP-compliant tool name normalization and validation
• Error Handling: Tool-level vs protocol-level error distinction
• Scope Metadata: OAuth2 scope extraction and management
• MCP 2025 Messages: Support for tasks, sampling, and URL elicitation
• Consent URLs: OAuth2 consent URL builders for incremental authorization This package provides stable TypeScript types that are shared across the OpenAPI-to-MCP ecosystem.

Installation

npm install openmcp-core

Usage

import type { MCPTool, MCPServerConfig, OpenAPIOperationRef } from 'openmcp-core';

// Define an MCP tool
const tool: MCPTool = {
  name: 'getWeather',
  description: 'Get weather information for a location',
  inputSchema: {
    type: 'object',
    properties: {
      location: { type: 'string' },
      units: { type: 'string', enum: ['celsius', 'fahrenheit'] }
    },
    required: ['location']
  }
};

// Define an MCP server configuration
const config: MCPServerConfig = {
  name: 'weather-service',
  description: 'Weather API MCP server',
  tools: [tool]
};

// Reference an OpenAPI operation
const operationRef: OpenAPIOperationRef = {
  operationId: 'getWeather',
  path: '/weather',
  method: 'get'
};

API Reference

MCPTool

Represents a tool that can be executed by an MCP server.

type MCPTool = {
  name: string;
  description: string;
  inputSchema: unknown; // JSON Schema-ish
};

Properties:

• name: Unique identifier for the tool
• description: Human-readable description of what the tool does
• inputSchema: JSON Schema definition for the tool's input parameters

MCPServerConfig

Defines the complete configuration for an MCP server.

type MCPServerConfig = {
  name: string;
  description?: string;
  tools: MCPTool[];
};

Properties:

• name: Unique identifier for the MCP server
• description: Optional description of the server
• tools: Array of tools available in this server

OpenAPIOperationRef

Lightweight reference to an OpenAPI operation, used for early-stage filtering and transformation before full extraction.

type OpenAPIOperationRef = {
  operationId: string;
  path: string;
  method: string;
};

Properties:

• operationId: The OpenAPI operation ID
• path: The API path (e.g., /users/{id})
• method: The HTTP method (e.g., get, post, put, delete)

License

MIT