@modusop/mcp-server

Stdio→HTTP proxy for [Modus Brain](https://brain.modusop.app) — gives any MCP-aware AI client (Claude Desktop, Cursor, Cline, Continue.dev, etc.) access to your ModusOp organisation's knowledge base.

What it does

This package is a thin proxy. It speaks the MCP stdio transport on one end and forwards every JSON-RPC request to Modus Brain's HTTP MCP endpoint on the other.

All tool implementations live in Modus Brain itself — when ModusOp ships a new Brain tool, every install of this package picks it up automatically on the next request. No re-publish, no version bump, no user action needed.

If your AI client speaks remote HTTP MCP natively, you don't need this package at all — point it directly at https://brain.modusop.app/mcp. This package exists for clients that only speak stdio.

Setup

1. Get a Brain token

Sign in at brain.modusop.app, generate a token labelled for the device or person who'll use it, copy the plaintext value (you only see it once).

2. Add to your AI client's MCP config

Claude Desktop — ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "modusop-brain": {
      "command": "npx",
      "args": ["-y", "@modusop/mcp-server"],
      "env": {
        "MODUSOP_API_TOKEN": "mo_brain_..."
      }
    }
  }
}

Cursor / Cline / Continue.dev — .cursor/mcp.json (or the equivalent):

{
  "mcpServers": {
    "modusop-brain": {
      "command": "npx",
      "args": ["-y", "@modusop/mcp-server"],
      "env": {
        "MODUSOP_API_TOKEN": "mo_brain_..."
      }
    }
  }
}

3. Restart your client

Quit and reopen. The Modus Brain tools should appear in the MCP indicator within a few seconds.

Env vars

Available tools

Whatever Brain exposes — tools/list reflects the current set. As of v1.0.0:

• whoami — identify the user + org this token is scoped to
• search_knowledge — semantic search over the org KB
• get_chunk — deep-dive on a specific search result
• list_recent — recently indexed KB items
• get_client_brief — synthesised client one-pager
• add_observation — append a note
• add_decision — record context + decision + rationale
• link_observation — typed link between two chunks
• request_delete — admin-gated removal

Migrating from 0.x

Versions 0.x of this package implemented tools in-package and talked to ModusOp's older /api/mcp endpoint with an MO API token from /settings/api-tokens. v1.0.0 retires that path:

• Generate a new Brain token at brain.modusop.app, not an MO API token
• Replace the value of MODUSOP_API_TOKEN with the new token
• No other config change needed — same command, same args, same env var name

Old tools (search_projects, search_clients, get_client_context, start_timer, etc.) are no longer present in this package's catalogue. They've been retired in favour of Brain's tools, which cover the same surface plus knowledge-base search and append-writes. If you need the old tool set, pin to @modusop/[email protected] — it still works but won't receive updates.

Local development

git clone https://github.com/jwwd-repos/modusop-mcp.git
cd modusop-mcp
npm install
MODUSOP_API_TOKEN=... npm run dev

The proxy reads JSON-RPC on stdin and writes responses on stdout, so test it manually with:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami"}}' \
  | MODUSOP_API_TOKEN=... npm run dev

Licence

See LICENSE.md.