Networking Migration Reference

Step-by-step migration guides for moving between networking APIs. Covers three migration paths with before/after code examples, mapping tables, and benefit analysis.

When to Use This Reference

Use this reference when you need to:

• Migrate from BSD sockets to NWConnection
• Upgrade from NWConnection (iOS 12-25) to NetworkConnection (iOS 26+)
• Replace URLSession StreamTask with NetworkConnection
• Understand the mapping between old and new APIs
• Decide whether to migrate or stay with your current API

Example Prompts

Questions you can ask Claude that will draw from this reference:

• "How do I migrate from BSD sockets to NWConnection?"
• "What's the equivalent of NWConnection's stateUpdateHandler in NetworkConnection?"
• "How do I replace completion handlers with async/await for networking?"
• "Should I migrate from URLSession StreamTask to NetworkConnection?"
• "What are the benefits of moving to NetworkConnection on iOS 26?"
• "How do I replace [weak self] patterns when migrating to async/await?"

What's Covered

• BSD sockets to NWConnection -- Mapping table for socket/connect/send/recv/bind/listen/accept to their NWConnection equivalents, with complete before/after code examples
• NWConnection to NetworkConnection -- Completion handlers to async/await, stateUpdateHandler to async sequences, manual JSON to built-in Coder protocol
• URLSession StreamTask to NetworkConnection -- When to migrate (need UDP, custom protocols) vs when to stay (HTTP, WebSocket, caching)
• API mapping tables -- Side-by-side equivalences for each migration path
• Line count reductions -- Quantified improvements (20 to 10 lines, 30 to 15 lines)
• Memory management changes -- Why [weak self] is eliminated with async/await

Documentation Scope

This page documents the axiom-networking-migration reference skill -- migration guides Claude uses when helping you move between networking API generations. The skill contains complete before/after examples for each migration path.

• For current networking patterns, see networking
• For legacy iOS 12-25 patterns, see networking-legacy
• For troubleshooting connections, see networking-diag

Related

• networking — Modern networking patterns and architecture decisions
• networking-legacy — NWConnection patterns for iOS 12-25
• network-framework-ref — Complete Network.framework API reference
• networking-diag — Connection failure troubleshooting

Resources

WWDC: 2018-715, 2025-250

Docs: /network, /network/nwconnection