About Fitness Tools
Fitness Tools is a deterministic calculator suite for fitness developers and MCP clients, covering metabolism, body composition, lifting, and nutrition. Each calculator reports a consensus from multiple published formulas.
Key features
- 01BMR and TDEE calculations
- 02Adaptive TDEE calculations
- 03Body fat and 1RM calculations
- 04Macro calculations
- 05Powerlifting attempts and natural muscular potential
Use cases
- 01Integrate fitness calculators into an app
- 02Estimate daily energy expenditure and macros
- 03Assess body fat and lifting attempts
MCP support
Its MCP stdio server exposes each calculator as a tool for agents and LLM clients. A hosted MCP endpoint is also available.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcpclaude mcp add --transport http almostjacked-fitness-tools https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp{"mcpServers":{"almostjacked-fitness-tools":{"type":"http","url":"https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp"}}}Open in Cursor{"servers":{"almostjacked-fitness-tools":{"type":"http","url":"https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp"}}}Open in VS Code{"mcpServers":{"almostjacked-fitness-tools":{"type":"http","url":"https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp"}}}{"mcpServers":{"almostjacked-fitness-tools":{"serverUrl":"https://fitness-tools-mcp.ajwallacemusic.workers.dev/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
Tools
10| Parameter | Type | Required | Description |
|---|---|---|---|
| age | number | Yes | |
| sex | enum | Yes | male | female |
| height | object | Yes | |
| height.unit | enum | No | cm | in | mm |
| height.value | number | Yes | |
| weight | object | Yes | |
| weight.unit | enum | No | kg | lb |
| weight.value | any | Yes | |
| methods | any | No | |
| activity | any | Yes | |
| body_fat | any | No | |
| lean_mass | any | No |
Details
From the project READMEFitness 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 withnpx @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
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
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.
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.