Consent in XMTP

Key Takeaways

• What is consent? Simply put, consent is who you allow and who you block
• Why it matters: Your choices about who can message you should be private and work across all apps
• How it works: Each wallet maintains a private, encrypted list of allowed and blocked addresses
• Future-proof: XMTP is making it easier to manage messaging permissions while keeping your choices private

Understanding Consent

Consent in XMTP manages who can message you across all apps you use:

For direct messages, it's about who you allow and who you block:

• Allow certain addresses to message you
• Block addresses you don't want to hear from

For group chats, it's about which groups you want to participate in:

• Join the group to receive its messages
• Block to stop receiving messages from the group

In both cases, new messages and invites stay in your message requests until you make a decision.

Privacy-First Design

Your choices about who can message you are private. This means:

• Only you can see who you've allowed or blocked
• Your choices are encrypted and visible only to you
• No one else can see your messaging preferences
• Blocked users don't know they're blocked

How Consent Works

The XMTP network maintains three private states for each potential messaging relationship:

pub enum ConsentState {
    Unknown,    // Default state for new contacts
    Allowed,    // Contacts you've allowed
    Denied,     // Contacts you've blocked
}

Implementation Note

Currently, consent preferences are client-side filters - they help apps determine which messages to show in your inbox, but don't prevent message transmission at the network level. The network plans to implement consent enforcement in the future.

When you receive a new message, it appears in your message requests. Apps typically show:

• Main inbox: Messages from allowed addresses and joined groups
• Message requests: New messages and invites you haven't decided about
• Hidden: Messages from blocked addresses and groups

The Future of Consent

XMTP's consent system is expanding in two major ways:

1. Programmable Consent

Today, individual apps implement their own ways of handling consent granting - through app-specific invite links, group joining mechanisms, or eligibility rules. We are creating an interoperable standard that works across the entire ecosystem:

• Apps can generate and validate consent links using a common protocol
• Links work consistently across all XMTP apps
• Supports flexible eligibility criteria (token ownership, DAO membership, etc.)
• Enables ecosystem-wide features like group invites and automated consent rules
• Maintains privacy while improving user experience

2. Network Enforcement

Moving from client-side filtering to network-level enforcement:

• Network validates consent before delivering messages
• Reduces network load from unwanted messages
• Provides stronger spam prevention
• Maintains end-to-end privacy

More details about network enforcement will be shared as development progresses.

Frequently Asked Questions

1. If I block someone, will they know?

   No, blocked users aren't notified of their status. From their perspective, it appears the same as if you haven't responded to their message.

2. Can I revoke consent after granting it?

   Yes, you can always privately revoke consent. The other party won't be notified, but you'll no longer see their messages.

3. What happens if someone I blocked is in a group chat with me?

   Apps typically show you that the blocked user sent a message but protect you from its content with a "tap to unhide" option. However, the exact UI implementation may vary by app.

4. Does blocking someone remove our message history?

   No, blocking only affects new messages. Previous conversations remain in your app but may be hidden from view depending on the app's design.

5. What happens when someone messages me from a different wallet than before?

   Each wallet address is treated separately for consent purposes. If someone messages you from a new address, that message will appear in your message requests, even if you've allowed their other address.

6. How will programmable consent criteria work?

   You'll be able to define specific conditions that automatically grant consent when met. These criteria will be evaluated privately - others won't see what rules you've set.

   Consent rules will use cryptographic signatures to ensure they can't be forged or tampered with. They can be configured to expire after a certain time or number of uses.

7. Will I be able to mute conversations?

   Yes, XMTP plans to add muting capabilities to the protocol, allowing you to temporarily silence notifications while maintaining consent preferences.