tectonic plates MCP server

Tectonic

Tectonic is a barbell strength-training tracker. An account logs workouts; a workout holds sets of an exercise at a weight and a rep count, in the order they are lifted. All weights are integer pounds.

What makes it more than a list is that a session is written before it is lifted. A program expands into ordinary set rows — warmup ramp included, every weight rounded to something a bar can actually be loaded to — so lifting is tapping through a list that already knows what comes next, and each row keeps the prescription beside what was actually done. An MCP endpoint exposes the same data to an LLM as a connector, which is the second half of this file.

The stack is Roda and Sequel on Postgres, with Rodauth for accounts and rodauth-oauth for the OAuth 2.1 authorization server the MCP endpoint authenticates against. Views are ERB with Tailwind from a CDN, and htmx for the parts of the session screen that have to change without a page load. It deploys to Render.

What it does

/workouts/:id, which is the record of one. A progress bar across the top, sets grouped by lift with warmups dimmed, the per-side plate breakdown under each weight ("per side 1×25 1×10"), and a Done button per set that toggles, so a mis-tap is undone by tapping again. A set lifted differently is entered inline and the row turns amber rather than lime, because done-as-written and done-differently have to read differently. The whole session gets an RPE rating, with a bar-speed guide for choosing one.

• Session view (/workouts/:id/session) — the gym-floor screen, as distinct from

yourself. A built-in exercise is visible to everyone but the sets shown under it are only ever your own.

• Exercises — 54 built-in barbell movements shared by every account, plus any you add

editing one yet.

• Workouts — list, record view, reschedule, delete.
• Programs — the engine below. Authored in Ruby and run from rake; there is no UI for

• Accounts — Rodauth login, account creation, logout, remember-me.
• MCP — audited, per-account tools over an OAuth 2.1-authenticated endpoint at /mcp.

Getting started

You need Ruby at the version in .ruby-version (the Gemfile reads the same file, so the two cannot drift), a local Postgres, and — only for the browser specs — Firefox with geckodriver.

bundle install
npm install        # only for the stylesheet; see below

Environment

dotenv loads .env when the app is required, and .env-example is a file to copy: cp .env-example .env gives a working development setup, pointed at the tectonicdevelopment database rake db:create makes below. The keys that are secrets in a deployment are commented out there rather than left blank, each with the command that generates it, because a blank is worse than an absence here — dotenv sets the name to the empty string, every fallback in this project tests for nil, and an empty DATABASEURL reaches Sequel.connect and raises rather than falling back to a default.

Shortened. The full README is on GitHub.