Show HN: A JSON MCP that doesn't clutter your LLM context

A Model Context Protocol (MCP) server that provides JSON schema generation and filtering tools. This server uses quicktype to convert JSON samples into TypeScript type definitions and offers JSON data filtering capabilities.

Particulary helpful for JSON files that are on the larger side which contains data you don't want included in your LLM context.

• JSON Schema Generation: Convert JSON files into TypeScript type definitions using quicktype-core
• JSON Filtering: Extract specific fields from JSON data using shape-based filtering
• MCP Integration: Seamlessly integrates with Claude Desktop and Claude Code
• Type Safety: Built with TypeScript and includes comprehensive error handling

Generates TypeScript type definitions from JSON files.

Parameters:

• filePath: Path to the JSON file to analyze

Example:

Generates TypeScript interfaces with proper typing.

Extracts specific fields from JSON data using a shape definition.

Parameters:

• filePath: Path to the JSON file to filter
• shape: Shape object defining which fields to extract

Shape Examples:

1. Clone this repository:

2. Install dependencies:

3. Build the server:

Add this server to your Claude Desktop configuration file:

Add this server to your Claude Code MCP settings:

Add a new server with:

• Name: json-mcp-server
• Command: node
• Args: ["/path/to/json-mcp-server/build/index.js"]

Or, use the npx method for easier setup:

Or claude mcp add json-parser node /path/to/json-mcp-server/build/index.js

• npm run build - Compile TypeScript and make executable
• npm run start - Run the compiled server
• npm run inspect - Run with MCP inspector for debugging
• npx tsc --noEmit - Type check without emitting files

Test the server using the MCP inspector:

This will start the server with the MCP inspector interface for interactive testing.

The server includes error handling for:

• File not found errors
• Invalid JSON format
• Quicktype processing errors
• Shape filtering errors