Legal. Updated 2026-11-01
Subprocessors
Marrow uses a small number of third-party services to operate the platform. This page lists every one of them, what they do for us, and where they're based. We update it before any new subprocessor goes live. If something on this list materially changes, we notify coaches in advance and give them a chance to object before the change takes effect.
This page is referenced in the Coach Founder Agreement (Section 4) and the Marrow Privacy Policy. Athletes' data is processed by Marrow on behalf of each coach, except Labs, which are the member's own (see Labs below). The same subprocessor list applies whether you signed up as a coach, an athlete, or a gym admin.
| Vendor | What they do for Marrow | Data handled |
|---|---|---|
| Stripe Payments Inc. USA. Privacy policy | Payment processing for coach subscriptions to Marrow and for athlete subscriptions to coaches via Stripe Connect Express. Coach is the merchant of record for athlete billing. | Coach + athlete name, email, billing address, payment method tokens. Marrow never sees full card numbers. |
| Cloudflare, Inc. USA. Privacy policy | DNS, edge network, asset delivery, Worker compute, KV storage for operational data (for example onboarding state, idempotency keys and rate limits), and R2 object storage for the files people add. | IP addresses and browser details for abuse prevention. In R2: profile pictures, progress photos, body scan photos, lab report files, meal plan documents and coach website images. All requests to Marrow pass through Cloudflare. |
| Supabase, Inc. USA. Privacy policy | Application database and sign in (email and password, plus the emailed one time password reset link). | All application data, in PostgreSQL. Row level security policies govern what a signed in person's own token can reach; Marrow's server reads with a service role key and does its own checks, as our security page explains. |
| Kit (formerly ConvertKit) USA. Privacy policy | Transactional and nurture email sequences for coach prospects and athlete signups. Form-submission tagging. | Email address, first name, tags reflecting funnel stage. |
| Postmark (Wildbit) USA. Privacy policy | One-off transactional emails (welcome notes, payment receipts, password-reset-style flows) outside of Supabase's built-in auth email. | Email address, name, payload of the transactional message. |
| Plausible Analytics Estonia, EU. Privacy policy | Privacy-friendly page-view analytics on marrowfitness.com. No cookies, no cross-site tracking, no fingerprinting. | Aggregated, anonymized page-view counts. No individual identifiers. |
| Meta Platforms, Inc. USA. Privacy policy | Advertising measurement on marrowfitness.com only, and only after the visitor chooses Accept in Your privacy choices. The Meta pixel records page views on public pages and sets a small cookie there. The Meta Conversions API tells Meta when a coach or gym owner finishes checkout for their own Marrow plan, and what the plan costs each month. Never loaded inside the Marrow app, on sign in or checkout pages, or on any member or athlete page. Meta receives this as a separate company under its own Business Tools Terms. Nothing is sent when your browser sends Global Privacy Control. See Advertising measurement with Meta in our privacy policy. | The event and the page it happened on. For a signup, the plan and its monthly price, the email address and Marrow account number turned into one way codes before they leave our server, browser type, IP address and the Meta cookie codes the browser already holds for our site. Never names, card details, training data or anything from inside the app. Member and athlete signups are never sent. |
| Sentry (Functional Software, Inc.) USA. Privacy policy | Production error monitoring on the iOS app and the website, masked screen replays in the iOS app for about 1 in 10 sessions and any session with an error, and on the website a masked replay of a page where an error happens, only after the visitor chooses Accept in Your privacy choices. | Stack traces, breadcrumbs, browser or device type. Before our servers send a report, they remove email addresses, payment keys and sign in tokens from it. In replays all text, images and icons are masked. See error monitoring in our privacy policy. |
| Anthropic, PBC USA. Privacy policy | Claude, only on an Anthropic key a gym or coach saves in Marrow themselves: a gym's WhatsApp front desk, the website studio and a coach's client list import. Marrow sends no member or coach data to Anthropic on an account of its own. | On that key only: a WhatsApp question the gym's own details do not cover, with the gym's details; the website being edited and the change asked for; and a client list's column names and what the values look like, never the values. Details in our privacy policy. |
| Telegram Dubai, UAE. Privacy policy | Alerts to Marrow's own team when something needs a person, such as a payment that did not finish. | The alert text. When a payment needs a person, that can include the account's email address and a Stripe reference. Never health or training data. |
| Slack Technologies, LLC USA. Privacy policy | New signup notices to Marrow's team, and the invite to Marrow's coach community workspace. | For a signup notice: the role, the name, a partly hidden email address, and the time. For a community invite: the coach's email address. |
| Mux, Inc. USA. Privacy policy | Video hosting and streaming for videos a coach uploads, when the Mux connection is switched on for Marrow. | The video files a coach uploads and playback details. Not used for live calls. |
| Cal.com, Inc. USA. Privacy policy | Booking a call with the Marrow team. | The name, email address and notes a person enters when they book. |
| Google LLC USA. Privacy policy | Google Fonts, which serves the typefaces on our pages. Google Calendar and Google Fit, only when a person chooses to connect their own Google account. | For fonts: IP address and browser details, as with any website. For a connected Google Calendar: the sign in token Google issues; Marrow does not write events to it yet. For Google Fit: see the wearable row. |
| Wearable companies: WHOOP, Oura, Garmin, Google Fit and Hume Health Each company's own location and privacy policy apply. | Only when a member chooses to connect that company's account to Marrow. | The member's sign in with that company, kept encrypted on our server and never in the database, and the daily numbers it sends back: sleep, resting heart rate, heart rate variability, stress, recovery, readiness, calories burned, active minutes and steps. Apple Health goes through the member's phone and is not a Marrow connection to Apple. |
How we add or change a subprocessor
When Marrow adds a new subprocessor, removes one, or makes a material change to how an existing one processes coach or athlete data, we notify coaches 30 days in advance via the email on file. Coaches who object can either request an alternative arrangement or terminate their agreement under the standard cancellation terms.
Routine vendor sub-changes (a vendor updating their own infrastructure providers) are not announced unless they materially change where data is stored or processed.
Data residency
Application data lives primarily in the United States. Cloudflare's edge network may cache static assets globally for performance, but application reads and writes route to US-based origin servers. Plausible Analytics is hosted in the European Union; only aggregated, anonymized page-view counts are sent there. Telegram, which carries alerts to our own team only, is based outside the United States.
Athletes
If you are an athlete, your data is processed by Marrow on behalf of the coach you train with. Marrow does not sell, license, or share athlete data with third parties for marketing purposes. Marrow does not market to athletes for any purpose other than transactional platform notifications.
Coaches own the relationship with their athletes. Coaches may export athlete data at any time. On termination of a coach's account, athletes are given 30 days to migrate their training history before deletion.
Labs
Labs are different. A member's lab reports belong to that member, not to their coach. Marrow holds them for the member, and a coach sees nothing unless the member turns on Share with my coach and agrees to share with that coach by name. A member can stop sharing at any time.
Lab files and values are stored with Cloudflare (the files) and Supabase (the values). Marrow sends lab files and values to no AI provider: a member who wants a file read shows it to their own Claude or ChatGPT and checks what it read before saving. Lab data never goes to Meta, to advertising, or to any marketing tool. The full detail is in our Consumer Health Data Privacy Policy.
Questions
Privacy and data questions: the contact form. We answer as soon as we can.
Services you connect with your own account
Some services are connected by a coach or a gym with their own account, and that account's own terms apply: an AI assistant a coach connects to their own Marrow account, a gym's own Twilio account for its WhatsApp front desk, and a coach's own booking or calendar tools. Marrow does not engage these companies for you; we name them so the picture is complete.