Your Hevy data.
AI that acts on it.

Connects to your Hevy account. Reads every set you've logged. Spots plateaus, adjusts routines, writes changes back. No more copy-pasting your training log into a chatbot.

open app source

v0.4.2 env:production gemini-2.5-flash europe-west1

Has my bench been stalling? What should I change?

Your bench has plateaued at 95 kg for 4 weeks. Chest volume dropped 18% since you added squash.

bench_press // last_4_weeks

top_set95 kg × 5

weekly_volume2,840 kg −18%

chest_sets_wk8 −3

est_1rm111 kg

Add a heavy triple at 102.5 kg on push day and bump accessory volume back up. Want me to update your routine?

Yes, update it.

sys.capabilities

A coach, not a chatbot.

It reads your data, does the analysis, and writes changes back. You just ask.

capability	description
Full history access	Every set, rep, and PR pulled live from Hevy via the MCP server.
Uses the `hevy-mcp` server (spawned per request) to call the Hevy API with your encrypted key. Fetches workouts, routines, exercises, and body measurements. Data is held in memory only — never persisted server-side. Typical response includes 50-200 workout sessions depending on history length.
Write-back to Hevy	Adjusts routines and syncs changes back to your Hevy account.
The agent can create, update, and delete routines and routine folders through the Hevy API. When you say "swap incline press for dumbbell flies on push day," it reads the current routine, makes the substitution, and writes it back. You can revert any change in the Hevy app or revoke API access at any time.
Transparent tool calls	Every API call is visible — you see what data it pulled and what it changed.
The chat UI shows a collapsible "tools used" section for each response. It includes the tool name, arguments (JSON), and the full response payload. No black box — you can verify exactly what the agent read or modified before and after each action.

browser  ──HTTPS──▶  cloud_run  ──spawn──▶  hevy-mcp  ──REST──▶  hevy_api
   │                    │                                    
   │ firebase_auth      ├──▶ vertex_ai (gemini-2.5-flash)    
   │ (id_token)         ├──▶ firestore (encrypted user data)  
   │                    └──▶ firebase_auth (token verify)     
   │                                                          
   └──▶ chat history held in browser only (never persisted)

sys.setup

Two minutes. Then it works.

auth

Sign in with Google or email. One click.

connect

Paste your Hevy API key. Get it from hevy.com/settings?developer. Encrypted at rest with AES-128 (Fernet), never stored in plain text. Requires Hevy PRO.

query

Ask anything. Training analysis, routine changes, volume checks. The agent has tool access to read and write your Hevy data.

sys.install

Use it your way.

Works in the browser. Even better installed — it launches full-screen from your home screen like a native app.

Install on your phone

Full-screen, no browser chrome, instant launch. No app store.

Open workout-agent.app in Safari
Tap Share at the bottom
Tap "Add to Home Screen"
Tap Add

Use in browser

No install needed. Open the app and start chatting.

open app

sys.examples

Things you can ask

Why has my bench stalled the last 3 weeks? reads: workout_history, exercise_stats

I tweaked my shoulder — adjust my push day. reads: routines · writes: routine_update

Playing squash twice this week. Reduce leg volume. reads: routines · writes: routine_update

What muscle groups am I neglecting this month? reads: workout_history, exercise_stats

Build me a push/pull/legs routine for hypertrophy. reads: routines · writes: routine_create

Show my last workout and tell me what to do next. reads: workout_history

Free. Open source. Two minutes to set up.