Two lines, and it is measuring

01

Add the package

No runtime dependencies at all, so it will not drag anything into your tree.

$ npm install @mcpulse/sdk
$ pnpm add @mcpulse/sdk
$ yarn add @mcpulse/sdk
$ bun add @mcpulse/sdk

02

Put the key in your environment

An ingest key is a secret — anyone holding it can write data into this MCP. Keep it out of the repository and out of your client bundle. You are shown the full key once, at creation, because only a hash of it is stored.

MCPULSE_KEY=mp_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

03

Wrap your server

One import, one call, after your tools are registered. watch returns the same server, so nothing downstream changes.

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { watch } from "@mcpulse/sdk";

const server = new McpServer({ name: "my-server", version: "1.0.0" });

// … your registerTool calls …

watch(server, { key: process.env.MCPULSE_KEY });

Serving over HTTP instead? Those servers build a new McpServer per request, so there is no long-lived instance to wrap — put it inside the factory, beside the tool registration. Calling watch once per request is expected and cheap: the session and its buffer are shared for the life of the process, which is what keeps your calls grouped into one session rather than one per request.

function createServer() {
  const server = new McpServer({ name: "my-server", version: "1.0.0" });

  // … your registerTool calls …

  return watch(server, { key: process.env.MCPULSE_KEY });
}

04

Restart and check back

On start the SDK sends one payload listing your tools and their schema sizes — that is what fills the tools table, so a server that has booted but never been called still shows what it costs per session. Tool calls follow as they happen, batched every 30 calls or 5 seconds.

Nothing arriving? Set debug: true to log every batch to stderr, and confirm the key has not been revoked.