JSON Filter MCP

[](https://mseep.ai/app/kehvinbehvin-json-mcp-filter) # JSON MCP Filter A powerful Model Context Protocol (MCP) server that provides JSON schema generation and filtering tools for local files and remote HTTP/HTTPS endpoints. Built with [quicktype](https://github.com/quicktype/quicktype) for robust TypeScript type generation. <a href="https://glama.ai/mcp/servers/@kehvinbehvin/json-mcp"> <img width="380" height="200" src="https://glama.ai/mcp/servers/@kehvinbehvin/json-mcp/badge" alt="JSON Server MCP server" /> **Perfect for**: Filtering large JSON files and API responses to extract only relevant data for LLM context, while maintaining type safety. ## ✨ Key Features - 🔄 **Schema Generation** - Convert JSON to TypeScript interfaces using quicktype - 🎯 **Smart Filtering** - Extract specific fields with shape-based filtering - 🌐 **Remote Support** - Works with HTTP/HTTPS URLs and API endpoints - 📦 **Auto Chunking** - Handles large datasets with automatic 400KB chunking - 🛡️ **Size Protection** - Built-in 50MB limit with memory safety - ⚡ **MCP Ready** - Seamless integration with Claude Desktop and Claude Code - 🚨 **Smart Errors** - Clear, actionable error messages with debugging info ## 🛠️ Available Tools ### `json_schema` Generates TypeScript interfaces from JSON data. **Parameters:** - `filePath`: Local file path or HTTP/HTTPS URL **Example:** ```javascript // Input JSON {"name": "John", "age": 30, "city": "New York"} // Generated TypeScript export interface GeneratedType { name: string; age: number; city: string; } ``` ### `json_filter` Extracts specific fields using shape-based filtering with automatic chunking for large datasets. **Parameters:** - `filePath`: Local file path or HTTP/HTTPS URL - `shape`: Object defining which fields to extract - `chunkIndex` (optional): Chunk index for large datasets (0-based) **Auto-Chunking:** - ≤400KB: Returns all data - >400KB: Auto-chunks with metadata ### `json_dry_run` Analyzes data size and provides chunking recommendations before filtering. **Parameters:** - `filePath`: Local file path or HTTP/HTTPS URL - `shape`: Object defining what to analyze **Returns:** Size breakdown and chunk recommendations ## 📋 Usage Examples ### Basic Filtering ```javascript // Simple field extraction json_filter({ filePath: "https://api.example.com/users", shape: {"name": true, "email": true} }) ``` ### Shape Patterns ```javascript // Single field {"name": true} // Nested objects {"user": {"name": true, "email": true}} // Arrays (applies to each item) {"users": {"name": true, "age": true}} // Complex nested { "results": { "profile": {"name": true, "location": {"city": true}} } } ``` ### Large Dataset Workflow ```javascript // 1. Check size first json_dry_run({filePath: "./large.json", shape: {"users": {"id": true}}}) // → "Recommended chunks: 6" // 2. Get chunks json_filter({filePath: "./large.json", shape: {"users": {"id": true}}}) // → Chunk 0 + metadata json_filter({filePath: "./large.json", shape: {"users": {"id": true}}, chunkIndex: 1}) // → Chunk 1 + metadata ``` ## 🔒 Security Notice **Remote Data Fetching**: This tool fetches data from HTTP/HTTPS URLs. Users are responsible for: ✅ **Safe Practices:** - Verify URLs point to legitimate endpoints - Use trusted, public APIs only - Respect API rate limits and terms of service - Review data sources before processing ❌ **Maintainers Not Responsible For:** - External URL content - Privacy implications of remote requests - Third-party API abuse or violations 💡 **Recommendation**: Only use trusted, public data sources. ## 🚀 Quick Start ### Option 1: NPX (Recommended) ```bash # No installation required npx json-mcp-filter@latest ``` ### Option 2: Global Install ```bash npm install -g json-mcp-filter@latest json-mcp-server ``` ### Option 3: From Source ```bash git clone <repository-url> cd json-mcp-filter npm install npm run build ``` ## ⚙️ MCP Integration ### Claude Desktop Add to your configuration file: ```json { "mcpServers": { "json-mcp-filter": { "command": "npx", "args": ["-y", "json-mcp-filter@latest"] } } } ``` ### Claude Code ```bash # Add via CLI claude mcp add json-mcp-filter npx -y json-mcp-filter@latest ``` Or add manually: - **Name**: `json-mcp-filter` - **Command**: `npx` - **Args**: `["-y", "json-mcp-filter@latest"]` ## 🔧 Development ### Commands ```bash npm run build # Compile TypeScript npm run start # Run compiled server npm run inspect # Debug with MCP inspector npx tsc --noEmit # Type check only ``` ### Testing ```bash npm run inspect # Interactive testing interface ``` ## 📁 Project Structure ``` src/ ├── index.ts # Main server + tools ├── strategies/ # Data ingestion strategies │ ├── JsonIngestionStrategy.ts # Abstract interface │ ├── LocalFileStrategy.ts # Local file access │ └── HttpJsonStrategy.ts # HTTP/HTTPS fetching ├── context/ │ └── JsonIngestionContext.ts # Strategy management └── types/ └── JsonIngestion.ts # Type definitions ``` ## 🚨 Error Handling ### Comprehensive Coverage - **Local Files**: Not found, permissions, invalid JSON - **Remote URLs**: Network failures, auth errors (401/403), server errors (500+) - **Content Size**: Auto-reject >50MB with clear messages - **Format Detection**: Smart detection of HTML/XML with guidance - **Rate Limiting**: 429 responses with retry instructions - **Processing**: Quicktype errors, shape filtering issues **All errors include actionable debugging information.** ## ⚡ Performance ### Processing Times | File Size | Processing Time | |-----------|-----------------| | < 100 KB | < 10ms | | 1-10 MB | 100ms - 1s | | 10-50 MB | 1s - 5s | | > 50 MB | **Blocked** | ### Size Protection - **50MB maximum** for all sources - **Pre-download checking** via Content-Length - **Memory safety** prevents OOM errors - **Clear error messages** with actual vs. limit sizes ### Best Practices - Use `json_dry_run` first for large files - Filter with `json_filter` before schema generation - Focus shapes on essential fields only ## 🌐 Supported Sources - **Public APIs** - REST endpoints with JSON responses - **Static Files** - JSON files on web servers - **Local Dev** - `http://localhost` during development - **Local Files** - File system access ## 💡 Common Workflows **LLM Integration:** 1. API returns large response 2. `json_filter` extracts relevant fields 3. Process clean data without noise 4. `json_schema` generates types for safety