Json5 Mcp

io.github.MukundaKattaPublished by GitHub account MukundaKattav0.1.0Updated Nov 3, 2026

Parse JSON5 (comments, trailing commas, unquoted keys) and emit strict JSON.

VerifiedSTDIODesktop onlyDeveloper Tools

Overview

AI-generated overview

Local MCP server that parses JSON5 (comments, trailing commas, unquoted keys) and converts it to strict JSON an assistant can use.

What you can do
  • Parse JSON5 text loosely into a real value, tolerating comments, trailing commas, unquoted keys, hex, NaN and Infinity
  • Serialize a value back into JSON5 for human-edited config files
  • Convert JSON5 input into strict JSON output, with optional indentation
When to use it
Useful when an assistant produces JSON-with-comments or reads config files such as tsconfig, .babelrc or mcp.json that are JSON5 in disguise, and the result must be accepted by a strict JSON parser.
Requirements
Runs as a local stdio process, typically launched with npx from the npm package @mukundakatta/json5-mcp, so Node.js and network access for the first install are needed. No authentication, environment variables or headers are declared.
Before you install
No credentials or write actions are involved; it only transforms text passed to it. Parsed content is handled by the local process, so avoid feeding it secrets you would not otherwise share with the assistant.

Installation

In SourceWeft

  1. Open Json5 Mcp in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

@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.

Source: packages/json5-mcp/README.md at commit 6fad5bb

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts