Live push-to-talk sessions, route tracking, and a social layer — built for the wall, not the desk.
What it does
Walkie-talkie style audio sessions over local WiFi. Host a group, invite your crew, and talk hands-free while you climb — no internet required.
Log every send, attempt, and project. Track grades, route types, and progress over time with your personal route library.
Add friends by QR code, see their sessions, and spin up group sessions together. Built for the people you actually climb with.
Apple Music keeps playing and automatically ducks when someone talks. Your playlist stays on; your conversation stays clear.
Sendline can detect nearby gyms and crags to automatically set context for your session — no manual entry needed.
Session status lives on your Dynamic Island and Lock Screen so you always know who's talking without unlocking your phone.
Last updated: April 20, 2026
Sendline ("we," "our," or "us") is committed to protecting your privacy. This policy explains what information we collect, how we use it, and your rights.
We collect the following categories of information when you use Sendline:
Your account and climbing data are stored securely using Supabase, a cloud infrastructure provider. Data is encrypted in transit and at rest. We do not sell your data to third parties.
Sendline uses your microphone for push-to-talk communication during live climbing sessions. Audio is transmitted directly between devices over your local network using Apple's MultipeerConnectivity framework. Audio is not recorded or stored on our servers.
Camera access is used to photograph routes you want to save and to scan QR codes when adding friends. Photos are stored only if you choose to save them to a route. We do not use your camera in the background.
Sendline uses your local network to discover and connect with nearby climbers during live sessions. No data is transmitted outside your local network during a session. An internet connection is only used for account sync and authentication.
We do not sell, rent, or share your personal data with third parties for advertising purposes. We may share data with service providers who help us operate the app (such as Supabase for database and authentication), under confidentiality agreements. We may disclose data if required by law.
You may request access to, correction of, or deletion of your personal data at any time by contacting us at support@sendline.app. You may also delete your account directly from the app settings, which will remove your personal data from our servers.
Sendline is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us so we can delete it.
We may update this policy from time to time. When we do, we will update the date at the top of this page. Continued use of the app after changes constitutes acceptance of the updated policy.
If you have questions about this privacy policy, please contact us at support@sendline.app.
We're here to help.
One person hosts a session, and nearby climbers can discover and join over your local WiFi or Bluetooth. No internet connection is needed for the audio — it runs directly between devices.
Yes. You can join live sessions as a guest without creating an account. An account is required to save routes, access your profile, and add friends.
The microphone is used exclusively for push-to-talk communication during live climbing sessions. Audio is never recorded or stored.
Open the Friends tab and tap "Add Friend." You can share your QR code or scan a friend's code. Both of you need to have the app installed.
Go to your Profile, then Settings, and choose "Delete Account." This permanently removes your account and all associated data from our servers.
Make sure all participants are on the same WiFi network. Check that microphone permission is granted in iOS Settings → Sendline. If issues persist, try closing and reopening the app on all devices, then have the host start a new session.