Asymmetric Sharing Model

Understand how Handrive's privacy-first sharing model protects you from unwanted content.

The Problem with Traditional Sharing

Most file sharing apps work like this:

Alice shares a folder with Bob → Folder appears in Bob's app

This seems convenient, but it has a problem: anyone can push content into your app. Spam, unwanted files, or even malicious content can appear without your consent.

Handrive's Solution

Handrive uses an asymmetric sharing model. Sharing requires action from both parties:

1. Alice adds Bob as a member     → Bob is granted access (but nothing happens yet)
2. Bob adds Alice as a contact    → Bob discovers Alice's shares

The key insight: granting access is not the same as accepting access.

How It Works

From the Sharer's Perspective

When you share with someone:

1. Create a share from a folder on your device
2. Add them as a member (by email)
3. Choose their role: Admin, Editor, or Viewer
4. Done - you've granted them access

You don't need them to be your contact first. You can share with anyone who has a Handrive account.

From the Receiver's Perspective

When someone shares with you:

1. Nothing appears in your app automatically
2. You must add the sharer as a contact
3. Only then do their shares appear in your sidebar
4. You can browse and download files

You're always in control of what appears in your app.

After Discovery: Updates Are Pushed

Once you've added someone as a contact and discovered their shares, updates are pushed to you when you're online:

• Share changes (name, settings) sync automatically
• Member changes (added/removed members, role changes) sync automatically
• File changes (renames, tag updates, deletions) sync automatically

However, you still need to actively discover new content:

• New shares - Browse your contacts to see new shares they've given you access to
• New files - Open a share to see new files that have been added

This keeps your app responsive without constantly downloading file lists you may not need.

Visual Example

Step	Alice (Sharer)	Bob (Receiver)
1	Creates "Project Files" share	—
2	Adds Bob as Editor	—
3	Waits...	Nothing in Bob's app
4	—	Adds Alice as contact
5	—	"Project Files" appears under Alice
6	—	Can now browse and download
7	Changes Bob's role to Admin	Role update pushed to Bob (if online)
8	Adds new files to share	Bob sees new files when he opens the share

Why This Matters

No Spam or Unwanted Content

Unlike email or cloud services, strangers can't push files into your app. Even if someone adds you as a member, you won't see their shares unless you choose to connect with them.

You Control Your Contacts

Your contact list is curated by you. Only people you've explicitly added can have their shares visible in your app.

Privacy by Default

The asymmetric model means:

• Sharing is an offer, not a push
• Receiving is an opt-in, not automatic
• Your app stays clean and organized

Protection from Malicious Content

Bad actors can't:

• Fill your app with unwanted files
• Use shares to send spam or phishing content
• Force you to see or interact with anything

Total Local Privacy

Beyond the asymmetric sharing model, Handrive is designed with total local privacy in mind.

What's Stored Where

Data	Location
Your email (for account verification)	Our server
Your shares	Your device only
Your members	Your device only
Your contacts	Your device only
Your files	Your device only

Our server only knows that you have an account. We don't know what shares you've created, who you've shared with, or what files you have. This information exists only in your local database.

Why It's Safe to Reset

Because all your shares, members, and contacts are stored locally, it's completely safe to delete your local database and start fresh:

• Your files are untouched — Shares are just pointers to folders on your disk
• No sync issues — Since there's no central server storing your shares/members/contacts, there's nothing to get out of sync with
• Rebuild anytime — Recreate shares, re-add members, re-add contacts — your collaborators' data is on their machines, so they can still discover your shares once you rebuild

This is useful when:

• The app isn't working as expected
• You want a clean slate
• You're troubleshooting issues

True Privacy Guarantee

Unlike cloud services that can access your files and metadata:

• We can't see your shares — Share information is stored locally
• We can't see your collaborators — Member lists are stored locally
• We can't see your files — Files stay on your device, transferred P2P
• We can't be compelled to share — We don't have access to give

The only thing we can verify is that an email address has a Handrive account. Nothing more.

Common Questions

What if I want to share with someone who doesn't use Handrive?

They'll need to create a Handrive account first. Once they sign in with the email you used, they can add you as a contact to discover your share.

Do both people need to add each other as contacts?

No. Only the receiver needs to add the sharer as a contact. The sharer just adds them as a member.

For two-way sharing (both people sharing with each other), both would need to add each other as contacts.

Can someone see that I added them as a member?

No. Adding someone as a member doesn't notify them or appear anywhere in their app until they add you as a contact.

What happens if I remove a contact?

Their shares disappear from your sidebar. You still have access (if they haven't removed you as a member), but you won't see the shares anymore unless you add them as a contact again.

What if my app data gets corrupted?

It's completely safe to delete your local database and start fresh. Your files are untouched (shares are just pointers to folders). Recreate shares, re-add members, and re-add contacts — there's no server data to get out of sync with. All your shares, members, and contacts are stored locally for total privacy.

Summary

Traditional Sharing	Handrive
Push model	Offer + Accept model
Content appears automatically	Content appears when you choose
Sender controls your view	You control your view
Spam possible	Spam-free by design
Metadata stored on servers	Metadata stored locally
Provider can access your data	Provider has no access

Handrive's asymmetric model puts you in control. You decide whose content appears in your app, not the other way around. And with total local privacy, your shares, members, and contacts stay on your device — we never see them.

Related Topics

• Shares - How shares work
• Contacts - Managing your contacts
• Member Roles - Permission levels