OpenCal

Log meals, check nutrition progress, and manage calorie goals in the OpenCal app — hands-free via your AI agent. Use when the user mentions eating, food, calories, macros, or nutrition.

OpenCal is a calorie & nutrition tracker with a beautiful iOS app. This skill lets your AI agent log meals, check progress, and update goals — so the user never has to open the app to track what they eat.

"I just had a burrito for lunch" → agent searches, scales, logs it → it shows up in the app instantly.

Setup

1. Download OpenCal from the App Store
2. Sign in and set your calorie/macro goals
3. Go to Profile → API Keys → Generate
4. Set the key:

   bash

   export OPENCAL_API_KEY="sk_your-key-here"
   

When to use this skill

User says	What to do
"I had a chicken sandwich for lunch"	Search food → scale nutrition → log it
"What did I eat today?"	Fetch today's log and summarize
"How much protein do I have left?"	Fetch log totals and compare to goals
"I want to cut to 1800 calories"	Update their calorie goal
"That last entry was wrong, remove it"	Delete the log entry
"What's in a banana?"	Search and show nutrition info (don't log)

Log a meal

The most common flow. User says something like "I had 200g chicken breast for lunch":

1. Search for the food:

bash

curl -s "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/food/search?q=chicken+breast&limit=5" \
  -H "Authorization: Bearer $OPENCAL_API_KEY" | jq '.results[] | {name, calories, protein, carbs, fat}'

Results are per 100g. Pick the best match.

2. Scale to the actual amount and log:

bash

curl -s -X POST "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/food/log" \
  -H "Authorization: Bearer $OPENCAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Chicken Breast",
    "amount": 200, "unit": "g",
    "calories": 330, "protein": 62, "carbs": 0, "fat": 7.2,
    "mealType": "lunch"
  }'

Multiply all nutrition values by amount / 100. The entry appears in the app immediately.

Use mealType: breakfast, lunch, dinner, or snack. Add "loggedAt": "2026-02-18T12:00:00Z" to backfill a past meal (defaults to now).

3. Confirm with the user: "Logged 200g chicken breast for lunch — 330 kcal, 62g protein."

Check daily progress

bash

curl -s "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/food/log?date=2026-02-18" \
  -H "Authorization: Bearer $OPENCAL_API_KEY" | jq '{totals, entries: [.entries[] | {name, calories, mealType}]}'

Omit ?date= for today. Returns each entry plus totals (calories, protein, carbs, fat).

Check and update goals

bash

# Current goals
curl -s "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/goals" \
  -H "Authorization: Bearer $OPENCAL_API_KEY" | jq

# Update (only include fields to change)
curl -s -X PUT "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/goals" \
  -H "Authorization: Bearer $OPENCAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"calorieGoal": 1800, "proteinGrams": 160}'

Delete a log entry

Get the entry ID from the daily log, then:

bash

curl -s -X DELETE "${OPENCAL_BASE_URL:-https://api.opencal.ai}/api/v1/food/log/{id}" \
  -H "Authorization: Bearer $OPENCAL_API_KEY"

Important notes

• Search results are per 100g — always scale before logging
• If the user doesn't mention an amount, ask — don't guess
• If search returns nothing, try shorter/simpler terms (e.g. "rice" instead of "steamed jasmine rice")
• Always confirm what you logged so the user can correct mistakes
• Rate limit: 100 requests/min