Local-first meansyour data never leavesthe deck.

§ 01 · What 'local-first' means here

Most nutrition apps store your data on a server. You sign in, the cloud holds the truth, and you're effectively borrowing access to your own logs.

BiteDeck flips that. Your meals, weights, body fat entries, fasts, water, and Coach history live in SwiftData on your iPhone. When iOS backs up your device to iCloud — your iCloud, not ours — the BiteDeck data is included automatically. We never receive a copy.

The implication: there is no server to subpoena, no breach to leak from, no migration to fail, no service to shut down.

§ 02 · The four off-device exceptions, named

Four narrowly scoped flows leave your phone, all routed through BiteDeck's own proxy so API keys stay off the device. Nothing in this list is retained, trained on, or tied to a BiteDeck account — because there is no account.

• Food photos

  Sent to Google Gemini Vision for recognition. The recognized item list comes back; the image isn't kept.

• Exercise descriptions

  Pasted text gets parsed into duration, intensity, and an estimated calorie burn.

• Ingredient descriptions

  Free-form ingredient text becomes structured macro estimates.

• Coach turns

  On-device context about your day accompanies each Coach message. Chat history lives on your phone; you can clear it anytime.

If you'd rather not scan, every meal can be logged by search, barcode, label OCR, or freeform — never an ingredient leaves the device.

§ 03 · HealthKit is the only integration

Apple Health is the single sanctioned bridge between BiteDeck and the rest of your life. It is opt-in. Every metric has its own toggle. Five reads. Ten writes. Either side of either flow can be turned off without disconnecting the rest.

Reads: steps, active energy, workouts, weight, body fat percentage.

Writes: calories, protein, carbs, fat, fiber, sugar, sodium, water, weight, body fat percentage.

Apple Health data never leaves your phone through BiteDeck — it moves between two on-device systems. Read the full account in the privacy policy.

§ 04 · Why on-device forecasting matters

Most calorie apps either skip forecasting entirely or send your weight and intake history to a server to compute the prediction. BiteDeck's 5-state weight forecast — Katch–McArdle BMR, body-fat-aware, 14-day lookback, 7-day rolling average, with reversed-trend detection — runs on your iPhone.

That isn't a marketing line. The math itself is in the binary. If you turn airplane mode on right now, the forecast still updates the next time you log your weight.

§ 05 · What you can take with you

Local-first that you can't export from is just vendor-lock-in by another name. So:

• CSV export

  Settings → Export Data → CSV. Full meal log plus weight history. AirDrop, email, or copy to Files.

• PDF summary

  Settings → Export Data → PDF. Today's plan and intake on one page.

No premium gate. No "contact support to extract your data."

§ 06 · Erase means erase

Settings → Erase All Data → type ERASE to confirm. That nukes SwiftData (every meal, weight, fast, body fat entry), progress photos in the BiteDeck folder, every UserDefaults key the app has ever written, and every BiteDeck-authored HealthKit sample.

The iCloud backup of your device may still hold older snapshots if you haven't excluded them — beyond that, no copy survives.

The confirmation step is intentional friction. Once it runs, it's irreversible.

§ 07 · How this compares

For the long-form comparison against the apps people usually ask about:

• BiteDeck vs. MyFitnessPal
• BiteDeck vs. Foodnoms