Privacy Policy

Effective date: May 2026 · Applies to the CurlBro iOS app

The short version

✓By default, all your workout data stays on your device — nothing is sent to our servers.

✓No analytics, no crash reporters, no advertising SDKs.

✓No account required. We don't know who you are.

✓Apple Health integration is optional and controlled entirely by you.

✓Optional Cloud AI feature (Claude API) is off by default and requires your own API key — only data you choose to share with it is transmitted, directly to Anthropic.

✓Data only leaves your device when you explicitly export, share, or enable Cloud AI.

Overview

CurlBro ("we", "our", or "the app") is a strength training workout tracker for iPhone. This policy explains what data the app handles, where it is stored, and what controls you have over it.

CurlBro does not have user accounts, does not connect to CurlBro servers, and does not collect personal information. The app functions entirely offline by default. Nothing you enter into CurlBro is transmitted to us, and nothing is transmitted to any third party unless you enable the optional Cloud AI feature described below in “Optional Cloud AI (Claude API)” or explicitly choose to share or export data yourself.

Data Stored on Your Device

The following data is created by you and stored locally using Apple's SwiftData framework. It never leaves your device automatically.

Workout plans — exercise names, sets, reps, weight targets, rest durations, notes
Workout logs — completed session records including exercises, weights, reps, RPE, duration, and timestamps
Body weight — captured at the end of a workout session (used for calorie estimates)
App settings — unit system (lb/kg), rest timer preferences, equipment list, display theme, and a randomly generated device identifier used only to associate local data

During an active workout, session state is temporarily cached to your device's local storage so the app can resume if it is interrupted. This cache is cleared when the session ends.

Apple Health (Optional)

CurlBro can optionally read and write data to Apple Health. You must explicitly grant permission for each of the following. Permissions can be changed at any time in the iOS Settings app under Health > Data Access & Devices.

Read — Body Mass: If permitted, the app reads your most recent body weight from Health to improve calorie estimates. This data is used only within the app and is not transmitted anywhere.
Write — Workouts: If the "Automatically save to Apple Health" setting is enabled, the app writes completed workout sessions (duration and estimated calories) to Apple Health. This feature is off by default.

Apple Health data is governed by Apple's own privacy policies. CurlBro does not retain or transmit any data read from Apple Health.

On-Device AI (Apple Intelligence)

On supported devices running iOS 26 or later with Apple Intelligence enabled, CurlBro may use Apple's on-device Foundation Models to generate workout plans, parse shared workouts, and produce post-session summaries and coaching notes. All inference runs entirely on your device. No prompts and no results are sent to CurlBro, to Apple, or to any other server.

Optional Cloud AI (Claude API)

CurlBro includes an optional Cloud AI feature that uses Anthropic's Claude API to generate and refine workout plans, and to power an interactive workout-planning chat. This feature is off by default and requires you to take two explicit actions in Settings:

Tick an in-app data-policy agreement that summarizes what is sent.
Supply your own Anthropic API key (BYOK — bring your own key). CurlBro never bundles or uses a shared key.

Your API key is stored in your device's Keychain. It is never synced to iCloud, never sent to CurlBro, and never written to logs, analytics, exported workouts, or UserDefaults. Disabling the toggle deletes the key from the Keychain.

When the feature is enabled, the following is transmitted directly from your device to api.anthropic.com on each workout build:

Your quiz answers (split, training goal, fatigue / energy level, sore muscles, equipment, experience level, superset / warmup / cooldown / finisher preferences, target session length)
Your profile name, if you have set one
The current date
The last 14 days of your workout history — absolute dates, total sets per session, and muscle groups trained per session (no per-set weights, reps, RPE, or notes)
The candidate exercise pool the on-device rules engine selected for this build — exercise IDs, names, primary muscles, and equipment requirements

If you use the “Chat with Claude” planning feature, the following is also transmitted to api.anthropic.com on every chat turn:

Your chat messages and the running message history for the current session
The equipment-filtered exercise catalog (the same catalog ships with the app, minus any exercises you have deselected)
The list of exercises you have deselected, so the assistant can avoid suggesting them

Chat transcripts are session-only and are never saved on this device. They are held in memory while the chat is open and discarded when you close it or quit the app.

Cloud AI never transmits HealthKit data, body weight, per-set training data (individual weights, reps, RPE), notes you have written on workouts, your device identifier, location, or any personally identifying information beyond an optional profile name. Traffic does not pass through CurlBro servers; the request is made directly from your device to Anthropic. Anthropic's processing of that traffic is governed by Anthropic's privacy policy — see anthropic.com/legal/privacy.

You can disable Cloud AI at any time in Settings > Cloud AI. The app then falls back silently to the on-device features described above.

Notifications

CurlBro may request permission to send local notifications for rest timer alerts between sets. These notifications are generated entirely on your device — no notification server is involved. You can disable them at any time in iOS Settings > Notifications > CurlBro.

Data Sharing and Export

Your data does not leave your device unless you take an explicit action:

Share a workout plan: You can share a workout as formatted text via the iOS Share Sheet (iMessage, Mail, Notes, etc.). You control what is included and where it goes.
Export workout history: You can export your full workout history as a JSON file from Settings. The file is shared via the iOS Share Sheet — you choose the destination (email, Files, cloud storage, etc.).
Import a workout: You can import workout files from AirDrop, the Files app, or email. No data is uploaded in this process.

We do not receive any of this exported data. We have no servers that accept it.

Third-Party SDKs and Analytics

CurlBro does not include any third-party analytics, advertising, crash reporting, or tracking SDKs. The app is built entirely with Apple's native frameworks (SwiftUI, SwiftData, HealthKit, UserNotifications) and an internal CurlBro framework. No third-party code in the app collects or transmits data.

The only third party the app communicates with at all is Anthropic, and only when you explicitly opt into the Cloud AI feature and supply your own API key — see “Optional Cloud AI (Claude API)” above for the exact data scope.

Video Demos and External Links

Some exercises in CurlBro link to a curated YouTube video demonstration. When you tap the demo button, the video opens in an in-app Safari sheet (SFSafariViewController) operated by Apple. This component runs in a separate process from CurlBro and shares cookies with your existing Mobile Safari session. CurlBro never loads YouTube or any third-party content into its own UI.

CurlBro does not observe, log, or transmit which videos you watch, when you watch them, or anything else about that browsing session. Once the sheet opens, you are interacting directly with YouTube through Safari, and YouTube / Google's data collection applies according to their own policies — see Google's privacy policy. You can dismiss the sheet at any time to return to CurlBro.

The list of videos shipped with the app is curated by CurlBro and stored locally with the exercise catalog. No video content is fetched or pre-loaded until you tap a demo.

Affiliate Links

CurlBro may contain affiliate links to third-party products or services (such as fitness equipment, supplements, or related apps). If you make a purchase through one of these links, CurlBro may earn a commission at no additional cost to you.

Affiliate relationships do not influence which products or exercises we feature. We only link to products we believe may be relevant to your training. You are never required to purchase anything through an affiliate link, and clicking a link does not share any personal information with us.

Affiliate links, when present, will be disclosed at the point of recommendation.

Children's Privacy

CurlBro is not directed at children under 13. We do not knowingly collect personal information from children. Because the app does not collect or transmit any data, there is no data for us to hold about any user of any age.

Deleting Your Data

Because all data is stored locally on your device, you are in full control of it:

Delete individual workouts or logs from within the app.
Remove all app data by going to iOS Settings > General > iPhone Storage > CurlBro > Delete App.
Revoke Apple Health permissions at any time in iOS Settings > Health > Data Access & Devices > CurlBro.

We do not hold any of your data on our end, so there is nothing for us to delete on your behalf.

Changes to This Policy

If we update this policy, the revised version will be posted at this URL with a new effective date. We encourage you to review it periodically. Continued use of the app after changes are posted constitutes acceptance of the updated policy.

Contact

Questions about this privacy policy? Contact us at contact@curlbro.com.