jsonfmt-mcp

MCP server for JSON tools — 21 tools for AI agents

Format, validate, convert, diff, repair, query, and analyze JSON from Claude, Cursor, VS Code, or any MCP client.

Install

Claude Desktop

Add to ~/.config/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "jsonfmt": {
      "command": "npx",
      "args": ["jsonfmt-mcp"]
    }
  }
}

Claude Code

Add to .mcp.json in your project:

{
  "mcpServers": {
    "jsonfmt": {
      "command": "npx",
      "args": ["jsonfmt-mcp"]
    }
  }
}

VS Code (Copilot)

Add to settings.json:

{
  "mcp": {
    "servers": {
      "jsonfmt": {
        "command": "npx",
        "args": ["jsonfmt-mcp"]
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "jsonfmt": {
      "command": "npx",
      "args": ["jsonfmt-mcp"]
    }
  }
}

Tools (21)

Core

| Tool | Description | |------|-------------| | format-json | Pretty-print JSON with configurable indentation | | minify-json | Remove all whitespace | | validate-json | Check validity and return stats | | repair-json | Fix trailing commas, single quotes, comments, Python literals | | diff-json | Compare two JSON documents | | sort-keys | Sort object keys alphabetically |

Convert

| Tool | Description | |------|-------------| | convert-json | Convert to 11 formats: yaml, csv, typescript, python, go, rust, markdown, flatten, sql, dotenv |

Transform

| Tool | Description | |------|-------------| | redact-secrets | Replace passwords, tokens, API keys with [REDACTED] | | pick-fields | Keep only specified keys | | omit-fields | Remove specified keys | | merge-json | Deep merge two objects | | group-by | Group array by field | | sort-by | Sort array by field |

Query

| Tool | Description | |------|-------------| | jsonpath-query | JSONPath with wildcards, recursive descent, filters | | schema-validate | Validate against JSON Schema Draft-07 | | schema-generate | Infer schema from sample data |

Analysis

| Tool | Description | |------|-------------| | json-stats | Count keys, types, depth, bytes | | size-report | Size breakdown with largest keys | | generate-mock | Generate realistic mock data from template | | security-scan | Find exposed secrets, JWTs, AWS keys, IPs, emails | | decode-jwt | Decode JWT token (header + payload) |

Examples

Ask your AI agent:

"Format this JSON: {"name":"Alice","age":30}"

"Convert this JSON to TypeScript interfaces"

"Find all emails in this JSON using JSONPath: $..email"

"Scan this config for exposed secrets"

"Diff these two JSON configs and show what changed"

"Generate mock data from this API response template"

Resources

| URI | Description | |-----|-------------| | jsonfmt://formats | Available converter formats | | jsonfmt://jsonpath-guide | JSONPath syntax examples |

Prompts

| Name | Description | |------|-------------| | analyze-json | Analyze JSON structure and suggest improvements | | suggest-conversion | Recommend best output format for a use case |

Ecosystem

| Product | Link | |---------|------| | Web App (33 converters, 8 tabs) | jsonfmt.dev | | REST API (63 endpoints) | api.jsonfmt.dev/docs | | CLI | npm i jsonfmt-dev | | MCP Server | This package | | Chrome Extension | Chrome Web Store |

License

MIT — jsonfmt.dev