MCP Developer Utility - Schema Generator & Zod Validator for Claude & Cursor

A high-performance MCP server, Claude Desktop tool generator, and JSON schema validator that empowers developers to instantly design, validate, and convert Model Context Protocol tools. Effortlessly generate robust JSON schemas, type-safe Zod TS definitions, and complete template servers from samples, OpenAPI definitions, Postman collections, JSON schemas, or cURL commands.

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⚡ 30-Second Quickstart

Get up and running instantly with Claude Desktop or Cursor by linking this server to your configuration.

1. Configure Claude Desktop

Add this server to your local claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "mcp-dev-utility": {
      "command": "node",
      "args": [
        "/absolute/path/to/mcp-dev-utility/dist/index.js"
      ]
    }
  }
}

(Make sure to build the project first with npm run build and replace /absolute/path/to/mcp-dev-utility with the actual absolute path of this workspace.)

2. Worked Copy-Paste Example: Infer Zod & Schema From Sample

Ask Claude or use the MCP Inspector to run the infer-schema-from-sample tool:

Input Parameters:

• toolName: "create-user"
• description: "Creates a new system user"
• sample:

  {
    "username": "johndoe",
    "email": "john@example.com",
    "age": 30,
    "settings": {
      "theme": "dark",
      "notifications": true
    }
  }
  

Instant Generated Output (Zod Schema & MCP Template):

{
  "toolName": "create-user",
  "description": "Creates a new system user",
  "jsonSchema": {
    "type": "object",
    "properties": {
      "username": {
        "type": "string"
      },
      "email": {
        "type": "string"
      },
      "age": {
        "type": "number"
      },
      "settings": {
        "type": "object",
        "properties": {
          "theme": {
            "type": "string"
          },
          "notifications": {
            "type": "boolean"
          }
        },
        "required": [
          "theme",
          "notifications"
        ]
      }
    },
    "required": [
      "username",
      "email",
      "age",
      "settings"
    ]
  },
  "zodCode": "z.object({\n  username: z.string(),\n  email: z.string(),\n  age: z.number(),\n  settings: z.object({\n    theme: z.string(),\n    notifications: z.boolean()\n  })\n})",
  "serverTemplate": "import { McpServer } from \"@modelcontextprotocol/server\";\nimport { StdioServerTransport } from \"@modelcontextprotocol/server/stdio\";\nimport { z } from \"zod\";\n\nconst server = new McpServer({\n  name: \"custom-mcp-server\",\n  version: \"1.0.0\",\n});\n\nserver.registerTool(\n  \"create-user\",\n  {\n    description: \"Creates a new system user\",\n    inputSchema: z.object({\n      username: z.string(),\n      email: z.string(),\n      age: z.number(),\n      settings: z.object({\n        theme: z.string(),\n        notifications: z.boolean()\n      })\n    })\n  },\n  async (args) => { ... }\n);"
}

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🛠️ Features & Tools

The server registers seven primary developer utility tools:

1. generate-mcp-tool-code

Generates standard MCP input schema (inputSchema), Zod TypeScript validation code, and a fully functional, runnable @modelcontextprotocol/server TypeScript template based on a list of parameter definitions.

• Inputs:

  • name (string): The name of your custom tool (e.g. get-weather or query-db).
  • description (string): Human-readable prompt describing what the tool does (used by the model to call it).
  • parameters (array): A list of objects containing:
    • name (string)
    • type ("string" | "number" | "boolean" | "array" | "object")
    • description (string)
    • required (boolean, optional)

• Outputs:

  • jsonSchema: The fully structured JSON schema for MCP.
  • zodCode: Type-safe Zod TS code.
  • serverTemplate: Complete TypeScript file template showing how to register the tool.

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2. infer-schema-from-sample

Instantly infers a complete JSON schema, Zod TS validation code, and standard MCP server template from a sample JSON arguments object. This allows you to draft tool definitions by simply supplying examples of what the arguments should look like!

• Inputs:

  • toolName (string): The name of the tool (e.g., update-user).
  • description (string): Description of what the tool does.
  • sample (object or JSON string): A sample JSON arguments payload (e.g., { "id": 101, "payload": { "name": "Alice" } }).

• Outputs:

  • Inferred JSON schema.
  • Inferred Zod TS validation block.
  • Ready-to-go @modelcontextprotocol/server template.

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3. validate-tool-arguments

Validates a set of tool arguments (either a JSON object or raw string) against a provided JSON Schema to test if they conform to expectations. This is extremely useful for verifying mock client requests during local development.

• Inputs:

  • schema (object or string): The JSON Schema definition.
  • arguments (object or string): The payload/arguments to validate.

• Outputs:

  • valid (boolean): true if conforming.
  • errors (array of strings): High-fidelity error list detailing schema violations (paths and messages) if invalid.

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4. convert-openapi-to-mcp

Converts an OpenAPI 3.x operation schema (including path/query parameters and requestBody schemas) directly to a standard MCP tool schema, Zod validation code, and ready-to-run @modelcontextprotocol/server TypeScript template. This allows you to instantly migrate your existing REST API endpoints into fully-featured MCP tools.

• Inputs:

  • operation (object or JSON string): The OpenAPI operation object (containing parameters and/or requestBody).
  • toolName (string, optional): Override for the generated tool name (defaults to operationId).
  • toolDescription (string, optional): Override for the generated tool description (defaults to operation description or summary).

• Outputs:

  • toolName: The normalized name of the generated tool.
  • description: The prompt description.
  • jsonSchema: Combined MCP tool input JSON Schema.
  • zodCode: Unified Zod TS validation code (with query/body/path indicators).
  • serverTemplate: Complete TypeScript file template illustrating the tool registration.

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5. convert-postman-to-mcp

Converts a complete Postman collection (v2/v2.1) containing API requests (including query/path parameters, headers, urlencoded body, or raw JSON body) directly to standard MCP tool definitions (schemas + Zod code) and generates a combined runnable multi-tool MCP server template! This is highly effective for converting an entire Postman collection into a fully functioning multi-tool MCP server.

• Inputs:

  • collection (object or JSON string): The Postman Collection object or JSON string (v2/v2.1).

• Outputs:

  • collectionName: Name of the Postman Collection.
  • description: Description of the collection.
  • tools: An array of generated tools, each containing:
    • toolName: Normalized tool name.
    • description: Tool prompt description.
    • jsonSchema: MCP tool JSON Schema.
    • zodCode: Zod TS validation code.
  • serverTemplate: A complete combined @modelcontextprotocol/server TypeScript template registering and exporting all these tools.

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6. convert-curl-to-mcp

Converts a standard cURL command (including HTTP method, URL, headers, query parameters, and JSON or raw request body) to a standard MCP tool schema, Zod validation definitions, and a fully functional, runnable API client MCP server template! This allows developers to instantly turn any third-party API endpoint curl example into a fully-functional, runnable MCP tool with automatic argument mapping and secure Authorization setup.

• Inputs:

  • curlCommand (string): The full cURL command string to parse and convert.

• Outputs:

  • toolName: Normalized tool name.
  • description: Tool prompt description.
  • jsonSchema: MCP tool JSON Schema mapping curl parameters/body fields to arguments.
  • zodCode: Zod TS validation code.
  • serverTemplate: A complete runnable @modelcontextprotocol/server TypeScript template that uses native fetch to actually execute the API request dynamically mapping input arguments.

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7. convert-jsonschema-to-mcp

Converts a standard JSON Schema (v4/v6/v7/draft-07 or similar) to a standard MCP tool schema, Zod validation definitions, and a fully functional, runnable @modelcontextprotocol/server TypeScript template! This allows developers to instantly turn any existing JSON Schema representation of a tool or data structure into a complete, type-safe, and fully documented MCP tool definition.

• Inputs:

  • schema (object or string): The JSON Schema object or JSON string to parse and convert.
  • toolName (string, optional): Override for the generated tool name (defaults to schema title or my-schema-tool).
  • toolDescription (string, optional): Override for the generated tool description (defaults to schema description).

• Outputs:

  • toolName: Normalized tool name.
  • description: Tool prompt description.
  • jsonSchema: The parsed and validated MCP-compliant JSON Schema.
  • zodCode: Zod TS validation code.
  • serverTemplate: Complete TypeScript file template registering the schema-validated tool.

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🚀 Getting Started

Prerequisites

• Node.js (v18+)
• npm

Installation

Clone or navigate to the workspace, then install dependencies:

$npm install

Build & Test

• Compile TypeScript:

  $npm run build
  

• Run Unit Tests:

  $npm test
  

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🔌 Running & Debugging the Server

Since MCP servers communicate over standard I/O (stdio) transport, you can run and test them using either the MCP Inspector or by adding them to your Claude Desktop config.

A. Testing with the MCP Inspector (Recommended)

Launch the official MCP Inspector web UI to interactively view and trigger your developer utility tools:

$npx @modelcontextprotocol/inspector npx tsx src/index.ts

B. Integrating with Claude Desktop

Add mcp-dev-utility to your local claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Add the server to the mcpServers section:

{
  "mcpServers": {
    "mcp-dev-utility": {
      "command": "node",
      "args": [
        "/absolute/path/to/mcp-dev-utility/dist/index.js"
      ]
    }
  }
}

Restart Claude Desktop to make these developer utility tools accessible to the AI.

C. Apify Platform Self-Test Mode

When running on the Apify platform with no connected MCP client (or with {"selfTest": true} as input), the server automatically performs a quick self-test of the seven utility tools, writes the summary results to the default dataset, and exits cleanly (0) within seconds.