@mukundakatta/json5-mcp (MCP) Server

This MCP server parses JSON5—supporting comments, trailing commas, and unquoted keys—then emits strict JSON for downstream tools. It also handles JSON5 values such as hex, NaN, and Infinity, and supports round-tripping so strict JSON can be produced when required.

🛠️ Key Features

JSON5 parsing (“JSON with comments”) into real values
JSON5 serialization, including human-edited configuration use cases
Conversion from JSON5 input to strict JSON output
Supports hex, NaN, and Infinity

🚀 Use Cases

Converting LLM-produced “JSON-with-comments” into strict JSON
Reading configuration files that are JSON5 “in disguise” (e.g., tsconfig, .babelrc, mcp.json)
Normalizing inputs for tools that require strict JSON

⚡ Developer Benefits

Tools provided: parse_json5(text), to_json5(value, indent?), to_strict_json(text, indent?)
Consistent strict-JSON output for integrations

⚠️ Limitations

Described behavior focuses on transforming JSON5 to strict JSON; additional capabilities beyond the listed tools are not specified.

@mukundakatta/json5-mcp

MCP server for JSON5: parse JSON-with-comments, trailing commas, unquoted keys, hex / NaN / Infinity. Round-trip to strict JSON when downstream tools require it.

Tools

parse_json5(text) — loose parse to a real value
to_json5(value, indent?) — serialize for human-edited config
to_strict_json(text, indent?) — JSON5 in, strict JSON out

Why this exists

LLMs frequently emit JSON-with-comments thinking it's JSON. They also see config files (tsconfig, .babelrc, mcp.json) that are JSON5 in disguise. This server is the loose-parse + strict-emit round trip — feed it whatever the LLM produced, get back something JSON.parse accepts.

Install — Claude Desktop

json

{
  "mcpServers": {
    "json5": { "command": "npx", "args": ["-y", "@mukundakatta/json5-mcp"] }
  }
}

Same shape for Cursor / Cline / Windsurf / Zed.

License

MIT OR Apache-2.0.

io.github.MukundaKatta/json5-mcp