Motubrain.org

MCP config debugger

Check an MCP JSON config before wiring it into your client

Paste or adapt a local MCP config, validate JSON syntax, and review the common mcpServers shape before you add a server to Claude Code, Cursor, or another MCP-capable workspace.

Source boundary

Motubrain.org is an independent utility page. It does not claim official MCP, Claude, Cursor, or server-specific authority; use it as a preflight checklist before checking the docs for the exact client and server you run.

Keep the config as valid JSON: quoted keys, no comments, no trailing commas.
Prefer explicit server names so you can audit which tool can read which files or URLs.
Review command, args, env, and remote URL fields before trusting copied snippets.
Keep tokens, passwords, and API keys out of shared screenshots and pasted configs.
JSON config scratchpad

No common JSON shape issues found.

JSON parses and follows the common mcpServers shape. Still verify exact fields with your client and each MCP server source.

MCP config preflight sequence

Use this compact pass before turning on a new local or remote MCP server.

1

Parse the JSON

Fix syntax first. JSON config files usually reject comments, single quotes, and trailing commas even when a blog snippet looks close.

2

Check server shape

Confirm the server entry has the launch method your client expects, commonly a local command with args or a remote URL.

3

Map access

Write down what each server can read or execute: project folders, shell commands, browser access, databases, or remote APIs.

4

Confirm sources

Open the package, repository, or vendor docs for every server before installing a copied command.

What this MCP helper does and does not verify

The page is intentionally conservative: it catches common config mistakes and points you back to primary sources.

JSON syntax and common shape

The scratchpad checks whether the file parses and whether mcpServers entries look like usable server objects.

Security review prompts

Warnings call out remote URLs, secret-like values, env fields, and file access boundaries before you paste the config into a client.

Not an official validator

Exact fields, supported transports, and server options belong to your MCP client and each server's documentation.

Local AI workspace context

If you are building a broader self-hosted AI workspace, compare server permissions with the local app boundary.

MCP config FAQ

Practical boundaries for MCP JSON setup and debugging.