Install formulon-mcp

formulon-mcp is published to npm and runs unmodified through npx. Most MCP clients only need a one-line registration.

Node.js 22+ is required

The server uses Node 22 features. Earlier versions will fail to start. Check with node --version.

Claude Code

claude mcp add --scope user formulon -- npx -y @libraz/formulon-mcp

Verify with:

claude mcp list

formulon should report ✓ Connected. If it does not, the Claude Code docs include logs and troubleshooting steps.

Codex CLI

Add this entry to ~/.codex/config.toml:

[mcp_servers.formulon]
command = "npx"
args = ["-y", "@libraz/formulon-mcp"]

Restart codex and the server will appear in tool discovery.

Claude Desktop

Add formulon to claude_desktop_config.json (location depends on OS):

OS	Path
macOS	~/Library/Application Support/Claude/claude_desktop_config.json
Windows	%APPDATA%\Claude\claude_desktop_config.json
Linux	~/.config/Claude/claude_desktop_config.json

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

Restart Claude Desktop. The tools will be available in the next session.

Other stdio MCP clients

Any stdio-capable MCP client works. Point it at:

npx -y @libraz/formulon-mcp

Or, after a global install:

npm install -g @libraz/formulon-mcp
formulon-mcp

Glossary: stdio MCP server

A long-running child process that speaks JSON-RPC over stdin / stdout. The client owns process lifetime; killing the parent terminates the server. No port is opened.

From source

For development or to pin a specific fork:

git clone https://github.com/libraz/formulon-mcp.git
cd formulon-mcp
yarn install
yarn run build

Register the absolute path to the built dist/index.js:

claude mcp add --scope user formulon node /absolute/path/to/formulon-mcp/dist/index.js

Or install the latest main without a local clone:

npx -y github:libraz/formulon-mcp

Verifying the install

Inside any connected client, the model has access to:

• formulon_version — returns the loaded Formulon engine version.
• formulon_eval_formula — evaluates one Excel formula in a throwaway workbook.

Calling either is a low-cost smoke test.

Read next

• Workflow — the open / mutate / recalc / save loop.
• Tools — every tool, grouped by category.
• Security model — what the server is allowed to do.