Update to libxmtp 4.6.1-rc2

[xmtptools]

This PR updates the iOS bindings to libxmtp version 4.6.1-rc2.

Changes:

• Updated XMTP.podspec version to 4.6.1-rc2
• Updated binary URLs in Package.swift to point to the new release
• Updated checksum in Package.swift
• Updated Swift source file (xmtpv3.swift) from the new release

Base branch: main

[claude[bot]]

Claude finished @xmtptools's task —— View job

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Code Review Complete ✅

I've reviewed this PR which updates the iOS bindings to libxmtp 4.6.1-rc2. Here's my comprehensive feedback:

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Summary

This PR successfully integrates the latest libxmtp FFI bindings with new fork recovery features and sync improvements. The changes are well-structured and follow the existing patterns in the codebase.

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✅ Code Quality & Best Practices

Excellent

1. New Group.leaveGroup() method (Group.swift:761-763)

   • Clean implementation following the existing pattern
   • Properly throws errors and uses async/await
   • Correctly delegates to the FFI layer

2. Fork Recovery Implementation (Client.swift:28-71)

   • Well-designed enum for ForkRecoveryPolicy with clear cases
   • Proper conversion to FFI types
   • Good encapsulation in ForkRecoveryOptions

3. Sync Summary Return Type (Conversations.swift:32-45)

   • New GroupSyncSummary struct provides useful metrics
   • Properly initialized from FFI type
   • Public API is clean and intuitive

4. Test Coverage

   • Tests properly updated to handle new sync return types
   • No breaking changes to test logic
   • Tests verify the summary counts (GroupTests.swift:1169, 1173, etc.)

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⚠️ Potential Concerns

Minor Issues

1. Missing Test Coverage for leaveGroup() (Group.swift:761-763)

   • The new leaveGroup() method has no corresponding test
   • Recommendation: Add a test that verifies:
     • Member can successfully leave a group
     • After leaving, isActive() returns false for that member
     • Group membership count decreases appropriately
     • Other members can see the updated membership after sync

2. Whitespace/Formatting (Group.swift:760-761)

   • Line 760 has trailing spaces before the method
   • Recommendation: Run linter to fix formatting

3. Fork Recovery Options Not Validated

   • ForkRecoveryOptions accepts arbitrary group IDs without validation
   • When enableRecoveryRequests is .allowlistedGroups, empty groupsToRequestRecovery array might be confusing
   • Recommendation: Consider adding validation or documentation about expected usage patterns

4. API Client Cache Extended (Client.swift:150-153)

   • Cache key now includes gatewayHost but this could cause cache misses if gateway is being migrated
   • Minor concern: Monitor for unexpected behavior if gateway URLs change

Documentation

1. Fork Recovery Feature (Client.swift:28-71)

   • No inline documentation explaining when/why to use each policy
   • Recommendation: Add doc comments explaining:
     • What fork recovery is
     • When to use .none, .allowlistedGroups, or .all
     • What workerIntervalNs controls

2. Sync Summary (Conversations.swift:32-45)

   • No documentation on what "eligible" vs "synced" means
   • Recommendation: Add doc comments explaining:

     /// Number of conversations eligible for syncing
     public var numEligible: UInt64
     /// Number of conversations successfully synced
     public var numSynced: UInt64
     

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🔒 Security Review

No security concerns identified

• Fork recovery is opt-in via configuration
• No new permissions or capabilities exposed
• Encryption key handling unchanged
• All network operations follow existing secure patterns

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⚡ Performance Considerations

1. Sync Efficiency Improvement

   • New summary return type allows callers to track sync progress
   • Good for monitoring and UX feedback

2. Fork Recovery Background Work

   • workerIntervalNs controls polling frequency
   • Recommendation: Ensure default value (if any) doesn't impact battery life

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🐛 Potential Bugs

1. Optional Handling in Fork Recovery (Client.swift:412)

   • forkRecoveryOpts?.toFfi() passes optional to FFI
   • Question: Is nil properly handled on the Rust side?
   • Based on xmtpv3.swift:13793, it accepts FfiForkRecoveryOpts?, so this appears safe ✅

2. Breaking API Change (Conversations.swift:235-241)

   • syncAllConversations() now returns GroupSyncSummary instead of Void
   • Tests updated correctly (ConversationTests.swift:109, 111, etc.)
   • Verified: Not a breaking change for callers who ignore return value ✅

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📝 Recommendations

High Priority

1. Add test coverage for Group.leaveGroup()
2. Run linter to fix formatting issues

Medium Priority

1. Add documentation for fork recovery feature
2. Add documentation for sync summary fields
3. Consider validation for fork recovery options

Low Priority

1. Monitor API client cache behavior with gateway URLs
2. Verify fork recovery worker interval defaults

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FFI Binding Review (xmtpv3.swift)

The generated FFI bindings look correct:

• leaveGroup() properly defined as async throws function
• FfiGroupSyncSummary struct correctly implements Equatable, Hashable, Sendable
• FfiForkRecoveryOpts and FfiForkRecoveryPolicy properly defined
• Type converters follow established patterns
• All new types have proper memory management

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Conclusion

This PR is well-implemented and ready to merge with minor improvements suggested above. The code follows Swift and iOS best practices, maintains consistency with the existing codebase, and properly integrates the new libxmtp features.

The main action item is adding test coverage for the new leaveGroup() functionality before merging.

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Files Reviewed

• ✅ Package.swift
• ✅ Sources/XMTPiOS/Client.swift
• ✅ Sources/XMTPiOS/Conversations.swift
• ✅ Sources/XMTPiOS/Group.swift
• ✅ Sources/XMTPiOS/Libxmtp/xmtpv3.swift
• ✅ Tests/XMTPTests/ConversationTests.swift
• ✅ Tests/XMTPTests/GroupTests.swift
• ✅ XMTP.podspec

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[macroscopeapp[bot]]

Update XMTP iOS client to libxmtp 4.6.1-rc2 and add fork recovery options and group sync summary across Client, Conversations, and FFI bindings

Introduce fork recovery configuration in Client and return a structured group sync summary, while updating FFI bindings and backend connection parameters.

• Add ClientOptions.forkRecoveryOptions and pass forkRecoveryOpts to Client.initializeClient and local createClient calls in Client.swift; add ForkRecoveryPolicy and ForkRecoveryOptions with FFI mappers
• Change Conversations.syncAllConversations to return GroupSyncSummary and map from FFI in Conversations.swift
• Update generated FFI to new schema including fork recovery types, group sync summary, updated backend connection params, and leaveGroup in xmtpv3.swift
• Add Group.leaveGroup in Group.swift
• Bump binary target URL/checksum in Package.swift and set podspec to 4.6.1-rc2 in XMTP.podspec

📍Where to Start

Start with backend and client initialization changes in Client.initializeClient and connection methods in Client.swift, then review the FFI type and signature updates in xmtpv3.swift.

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Macroscope summarized a417168.