# FitFly Engine Muse connector

From musedirectory.ai, the independent directory of Meta Muse connectors. Not affiliated with Meta.

## FitFly Engine

Adaptive fitness coaching with auto-adjusting workouts based on how you feel and what you lift.

- Record: https://musedirectory.ai/connector/fitfly-engine
- Category: Lifestyle
- Developer: DropFly AI (https://workout-engine-production-5dd7.up.railway.app/connect)
- Muse status: Extra setup. Not in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
- Health: Working, 441ms, checked 2026-09-28T07:46:06Z
- Endpoint: https://workout-engine-production-5dd7.up.railway.app/mcp
- Auth: Needs an access key; Pricing: unknown
- Screening: Screened, no issues found (2026-09-25T07:02:12Z)
- Source: Found in the official MCP Registry (io.github.dropflyai/fitfly-engine) https://registry.modelcontextprotocol.io/v0/servers?search=io.github.dropflyai%2Ffitfly-engine

Personalized strength training programs that adjust daily based on readiness check-ins and logged performance. Provides exercise selection, target weights, progression tracking, and meal plans tailored to your goals and equipment.

Example request: "Show me today's workout with adjusted weights based on how I'm feeling, and generate a meal plan that hits my calorie and macro targets."

How to connect: Not in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use FitFly Engine to help me. It is a free service with an MCP server at https://workout-engine-production-5dd7.up.railway.app/mcp. It needs an API key from DropFly AI; ask me to enter it through your secure credential prompt. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.

Tools:
- get_todays_session: Today's workout: exercises, sets/reps, per-exercise load guidance and concrete target weights, plus nutrition targets and cycle status. Auto-applies the user's readiness check-in (autoregulation) if they've done one today. Call this to see what the athlete should do now.
- readiness_checkin: Record how the athlete feels today (energy, sleep, soreness — each 1–5). The engine scores readiness and, on the next get_todays_session, reshapes the workout accordingly (reduce volume / reduce intensity / recovery day). Returns the readiness score + modifier.
- log_workout: Record what the athlete actually lifted. The engine runs progression (double-progression, e1RM), detects PRs, and returns per-exercise outcomes (established/progressed/held/deloaded) with next-time targets. Weights are in kg.
- list_swap_options: Valid alternatives for an exercise — same muscle group, filtered to the athlete's equipment/level/injuries. Use before swap_exercise.
- swap_exercise: Replace an exercise with a valid same-area alternative. scope 'today' = just this session; scope 'program' = going forward. The new lift starts fresh (day-one calibration).
- get_program: The athlete's current multi-day program (render-ready).
- regenerate_program: Rebuild the whole program from the stored profile (~20s AI generation). Use after a profile change or a plateau.
- nutrition_targets: The athlete's daily calorie + macro targets, computed from body stats, activity, and goal.
- meal_plan: A day of meals hitting the athlete's targets, USDA truth-checked (flags feasible=false with a note when macros are approximate). Slow (~15s AI call).
- changelog: The 'what changed & why' feed — the engine's coaching decisions (volume bumps, deloads, swaps) in Coach Fly's voice. Use to explain to the athlete why their plan evolved.

Screening checks:
- MCP handshake: pass (Answered in 284ms)
- Domain against threat feeds (Cloudflare security DNS): pass (workout-engine-production-5dd7.up.railway.app not flagged)
- Published packages against the OSV malicious-package database: n/a (No npm or PyPI package published)
- Hidden instructions or invisible characters in tool text: pass (10 tools read, nothing found)
- Inputs asking for passwords, card numbers or seed phrases: pass (None found)
- Domain and redirects: pass (No redirects off the domain)
- AI review of purpose and tool behavior: pass (No concerns)