Fitness Tools

📖 Documentation · npm

Use it with your AI right now: add the hosted MCP connector https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp in claude.ai / ChatGPT settings, install one-click in Cursor or VS Code, or grab the Claude Desktop .mcpb.

Composable, deterministic fitness calculators — BMR/TDEE, body fat, 1RM, macros, activity multiplier, powerlifting attempts, and natural muscular potential. Each calculator runs several published formulas and reports a consensus across them.

This repo ships three separate, independently-usable artifacts:

@almostjacked/fitness-tools — the npm library. Validated, self-describing calculators that run natively in the browser and on the server. This is the product.
@almostjacked/fitness-tools-api — a reference HTTP server built on the library. It re-exposes the same calculators over HTTP (identical math, identical results) and is inert until you run or host it.
@almostjacked/fitness-tools-mcp — an MCP stdio server built on the library. It exposes the same calculators as MCP tools for agents/LLM clients (identical math), runnable with npx @almostjacked/fitness-tools-mcp.

Which one do you want?

You're…	Use	Why
Writing JS/TS (browser, Node, edge)	`@almostjacked/fitness-tools` (npm)	Runs in-process. Install, import, call. No server, no network.
Calling from another language / `curl` / a no-code tool	`@almostjacked/fitness-tools-api` (HTTP)	Same calculators over HTTP. You run/host it.
Building a remote frontend	`@almostjacked/fitness-tools-api`	Self-describing catalog + OpenAPI over the wire.
Wiring the calculators into an MCP client / agent	`@almostjacked/fitness-tools-mcp`	`npx` an MCP stdio server; one tool per calculator.

The API adds a network boundary, not capability. The package works the moment you install it; the server does nothing until it's running.

Documentation

New to it? Getting started
What each calculator does: Tools
Calling from an agent: Consumer guide
Working on this repo: AGENTS.md

Layout

Code

packages/core   @almostjacked/fitness-tools — the library (the product)
apps/api        @almostjacked/fitness-tools-api  — a reference HTTP server over the library
apps/mcp        @almostjacked/fitness-tools-mcp  — an MCP stdio server over the library

Develop

bash

corepack enable              # pnpm version is pinned in package.json
pnpm install
pnpm -r test                 # core + api + mcp test suites
pnpm -C packages/core build  # build the library
pnpm -C apps/api dev         # run the reference server on :8080

See each package's README — library · reference server.

License

MIT — free, open-source, and usable in commercial products. See LICENSE. Built on published formulas (Mifflin-St Jeor, US Navy, Jackson-Pollock, Epley, Casey Butt, etc.); contributions welcome.