Apple Health Skill

Talk to your Apple Health data — ask questions about your workouts, heart rate, activity rings, and fitness trends using AI.

Security Scan

The skill's behavior (it requires and instructs using a TRANSITION_API_KEY to send Apple Health data to an external service) is coherent with its description, but the registry metadata does not declare the required credential and the SKILL.md directs health data to a third-party API — these inconsistencies and the sensitive data flow merit caution.

Purpose & Capability

The skill's stated purpose (query Apple Health data via Transition) matches the runtime instructions (calls to api.transition.fun). However the registry metadata lists no required environment variables or primary credential while SKILL.md and README explicitly instruct setting TRANSITION_API_KEY. That metadata omission is an incoherence and could mislead users about required secrets.

Instruction Scope

SKILL.md stays on-purpose: it tells agents to call Transition endpoints for workouts, coach chat, performance stats, etc. Important: using the authenticated endpoints will cause the agent/service to send the user's Apple Health data to api.transition.fun (Transition) — this is expected for the skill's function but is a significant data-sharing action the user must approve.

Install Mechanism

This is an instruction-only skill with no install spec or code files, so nothing is written to disk by the skill itself. Lower install risk.

Credentials

The skill requires a sensitive API key (TRANSITION_API_KEY) to access personalized Apple Health data, but the registry's requires.env and primary credential fields are empty. Requiring a key that isn't declared in metadata is disproportionate / inconsistent and reduces transparency. The requested key, if supplied, grants access to personal health data via the third-party API.

Persistence & Privilege

The skill does not request always:true and has no install hooks or system-wide changes. It does not ask to modify other skills or system configs. Agent autonomous invocation is allowed (platform default) but not an additional privilege granted by this skill.

What to consider before installing

Before installing, be aware: the SKILL.md requires you to generate and set a TRANSITION_API_KEY (sensitive) and to grant the Transition app access to your Apple Health data — that data will be accessible to api.transition.fun. The registry metadata failing to list the required env var is an inconsistency you should question. Actions to consider: verify the skill's publisher and source (the README suggests a GitHub repo and a transition.fun homepage), read Transition's privacy/security policy, decide whether you trust this third party with health data, use a separate account or scoped key if possible, rotate/revoke the key after use, and refuse installation if the metadata or provenance cannot be confirmed.

Chat with your Apple Health data using AI. Ask about your workouts, heart rate trends, activity rings, VO2 Max, and more. Powered by Transition, which syncs with Apple Health to give AI agents access to your fitness data.

Setup

1. Download Transition and grant Apple Health access
2. Go to Settings > API Keys and tap Generate New Key
3. Set the environment variable:

export TRANSITION_API_KEY="tr_live_xxxxxxxxxxxxxxxxxxxxx"

No Auth Required

Workout of the Day

Generate a random structured workout — no account needed.

curl "https://api.transition.fun/api/v1/wod?sport=run&duration=45"

Parameters:

• sport — run, bike, swim, or strength (default: run)
• duration — minutes, 10-300 (default: 45)

Authenticated Endpoints

Base URL: https://api.transition.fun Auth: Pass X-API-Key header on every request.

AI Coach Chat

Ask questions about your Apple Health data. The AI coach has full context on your workouts and health metrics.

curl -X POST -H "X-API-Key: $TRANSITION_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"message": "How has my resting heart rate changed over the last month?"}' \
  "https://api.transition.fun/api/v1/coach/chat"

Example questions:

• "How many workouts did I do this week?"
• "What's my VO2 Max trend?"
• "How has my sleep been trending this week?"
• "Compare my running pace this month vs last month"
• "Should I take a rest day based on my recent training?"

Get Workouts

Retrieve scheduled workouts for a date range.

curl -H "X-API-Key: $TRANSITION_API_KEY" \
  "https://api.transition.fun/api/v1/workouts?start=2026-02-09&end=2026-02-15"

Parameters:

• start — Start date (YYYY-MM-DD, required)
• end — End date (YYYY-MM-DD, required)
• Maximum range between start and end is 90 days.

Performance Management Chart (PMC)

Get CTL (fitness), ATL (fatigue), and TSB (form) calculated from your Apple Health workouts.

curl -H "X-API-Key: $TRANSITION_API_KEY" \
  "https://api.transition.fun/api/v1/performance/pmc"

Performance Stats

Get FTP, threshold paces, heart rate zones, and other metrics derived from your Apple Health data.

curl -H "X-API-Key: $TRANSITION_API_KEY" \
  "https://api.transition.fun/api/v1/performance/stats"

Athlete Profile

curl -H "X-API-Key: $TRANSITION_API_KEY" \
  "https://api.transition.fun/api/v1/profile"

Chat History

curl -H "X-API-Key: $TRANSITION_API_KEY" \
  "https://api.transition.fun/api/v1/coach/history"

Rate Limits

Tier	Read Endpoints	AI Endpoints
Free	100/day	3/day
Paid	10,000/day	100/day

Tips for Agents

1. Use coach chat as the primary interface. It has full context on the user's Apple Health workouts, heart rate, and performance — just ask natural questions.

2. Check fatigue before recommending hard workouts. Call GET /api/v1/performance/pmc and look at TSB. If TSB is below -20, the athlete is fatigued.

3. Use the free WOD endpoint for quick workouts. No auth needed — great for users who just want a workout suggestion.

4. Date format is always YYYY-MM-DD for all date parameters.