Beta · 100% browser-side

MCP playground

Paste any Claude Desktop, Cursor, Windsurf or Continue config and instantly see what it really exposes — servers, runtimes, missing env values, duplicate keys, parse errors.

Paste your MCP config

Parsing happens 100% in your browser — nothing is uploaded.

No config yet

Paste a config on the left, or click "Load sample" to see how it works.

What gets checked

  • Schema

    JSON validity, missing command, malformed args, top-level mcpServers key.

  • Placeholders

    Detects <your-token>, YOUR_API_KEY, ... and similar — common reasons servers fail to start.

  • Catalog match

    Each entry is matched against 1800+ catalogued MCP servers — click through to docs and stability info.

  • Conflicts

    Duplicate server keys, runtime distribution, parse errors that would crash Claude on restart.

MCP playground — FAQ

  • What does the MCP playground do?

    It parses any Claude Desktop, Cursor, Windsurf or Continue config and shows what it actually exposes — server keys, runtimes, missing env values, duplicate names, schema errors. A pre-flight check before you restart your client.

  • Does it run my MCP servers?

    Not yet. The current version inspects the config statically — it parses the JSON, matches each entry against the Loadout catalog, flags placeholders and conflicts. A live execution mode (sandboxed servers + Anthropic API roundtrip) is on the roadmap.

  • Is my config sent anywhere?

    No. Parsing happens entirely in your browser. Nothing leaves the page — no telemetry, no upload, no backend.

  • How is this different from the builder?

    The builder helps you assemble a config from scratch. The playground inspects an existing one — paste anything you copied from a tutorial, a friend, or an old Claude Desktop install, and see what it really does.