Networking
You MUST use this skill for ANY networking work including HTTP requests, WebSockets, TCP connections, or network debugging.
Cursor Subagent Routing
Delegate to the appropriate Cursor subagent when this router calls for a specialized auditor.
Quick Reference
| Symptom / Task |
Reference |
| URLSession with structured concurrency |
See skills/networking-discipline.md |
| Network.framework anti-patterns |
See skills/networking-discipline.md |
| Deprecated API migration |
See skills/networking-discipline.md |
gRPC Swift — typed RPC, streaming, .proto codegen (WWDC 2026) |
See skills/networking-discipline.md |
| Pressure scenarios (reachability, sockets) |
See skills/networking-discipline.md |
| NetworkConnection (iOS 26+) API reference |
See skills/network-framework-ref.md |
| NWConnection (iOS 12-18) API reference |
See skills/network-framework-ref.md |
| TLV framing, Coder protocol |
See skills/network-framework-ref.md |
| NetworkListener, NetworkBrowser, Wi-Fi Aware |
See skills/network-framework-ref.md |
| Connection timeouts, TLS failures |
See skills/networking-diag.md |
| Data not arriving, connection drops |
See skills/networking-diag.md |
| ATS / HTTP / App Store rejection |
See skills/networking-diag.md |
| Production crisis diagnosis |
See skills/networking-diag.md |
| NWConnection patterns (iOS 12-18) |
See skills/networking-legacy.md |
| UDP batch, NWListener, NWBrowser |
See skills/networking-legacy.md |
| BSD sockets → NWConnection migration |
See skills/networking-migration.md |
| Push/calls on networks without internet (Local Push Connectivity, NEAppPushProvider) |
Use axiom-integration (skills/local-push-connectivity.md) |
| NWConnection → NetworkConnection migration |
See skills/networking-migration.md |
| URLSession StreamTask → NetworkConnection |
See skills/networking-migration.md |
Decision Tree
digraph networking {
start [label="Networking task" shape=ellipse];
what [label="What do you need?" shape=diamond];
start -> what;
what -> "skills/networking-discipline.md" [label="implement patterns,\nanti-patterns,\npressure scenarios"];
what -> "skills/network-framework-ref.md" [label="API reference\n(iOS 26+ or 12-18)"];
what -> "skills/networking-diag.md" [label="debug connection\nfailures"];
what -> "skills/networking-legacy.md" [label="iOS 12-18\nNWConnection patterns"];
what -> "skills/networking-migration.md" [label="migrate from\nsockets/URLSession"];
}
- URLSession with structured concurrency? →
skills/networking-discipline.md
- Network.framework / NetworkConnection (iOS 26+)? →
skills/network-framework-ref.md
- NWConnection (iOS 12-18)? →
skills/networking-legacy.md
- Migrating from sockets/URLSession? →
skills/networking-migration.md
- Connection issues / debugging? →
skills/networking-diag.md
- Typed RPC / streaming against a service you control? → gRPC Swift (
skills/networking-discipline.md)
- ATS / HTTP / App Store rejection for networking? →
skills/networking-diag.md + networking-auditor
- Certificate pinning, signing API requests, encrypting payloads? →
/skill axiom-security
- UIWebView or deprecated API rejection? → networking-auditor (Agent)
- Want deprecated API / anti-pattern scan? → networking-auditor (Agent)
Platform-specific networking
- watchOS low-level-networking limits (TN3135) → See axiom-watchos (skills/background-and-networking.md)
Pressure Resistance
When user has invested significant time in custom implementation:
Do NOT capitulate to sunk cost pressure. The correct approach is:
- Diagnose first — Understand what's actually failing before recommending changes
- Recommend correctly — If standard APIs (URLSession, Network.framework) would solve the problem, say so professionally
- Respect but don't enable — Acknowledge their work while providing honest technical guidance
Critical Patterns
Networking (skills/networking-discipline.md):
- URLSession with structured concurrency
- 8 red-flag anti-patterns (SCNetworkReachability, blocking sockets, hardcoded IPs)
- Decision tree for choosing TCP/UDP/TLS patterns
- NetworkConnection patterns (iOS 26+): TLS, UDP, TLV framing, Coder protocol
- 3 pressure scenarios with professional push-back templates
- Pre-shipping checklist
Network Framework Reference (skills/network-framework-ref.md):
- NetworkConnection (iOS 26+): all 12 WWDC 2025 examples
- NWConnection (iOS 12-18): complete API with examples
- TLV framing, Coder protocol, NetworkListener, NetworkBrowser
- Mobility: viability, better path, Multipath TCP, NWPathMonitor
- Security: TLS, certificate pinning, cipher suites
- Performance: user-space networking, ECN, service class, TCP Fast Open
Diagnostics (skills/networking-diag.md):
- Systematic decision tree for all connection failure types
- DNS failures, TLS certificate validation, message framing
- TCP congestion, IPv6-only cellular, VPN interference, ATS
- Production crisis scenario with professional communication templates
Legacy (skills/networking-legacy.md):
- NWConnection with TLS (completion handlers)
- UDP batch (30% CPU reduction)
- NWListener, NWBrowser (Bonjour discovery)
Automated Scanning
Networking audit → Delegate to the networking-auditor subagent or /axiom-audit networking (deprecated APIs, anti-patterns, and completeness gaps — transition handling, TLS coverage, connection cleanup, framework selection)
Anti-Rationalization
| Thought |
Reality |
| "URLSession is simple, I don't need a skill" |
URLSession with structured concurrency has async/cancellation patterns. skills/networking-discipline.md covers them. |
| "I'll debug the connection timeout myself" |
Connection failures have 8 causes (DNS, TLS, proxy, cellular). skills/networking-diag.md diagnoses systematically. |
| "I just need a basic HTTP request" |
Even basic requests need error handling, retry, and cancellation patterns. |
| "My custom networking layer works fine" |
Custom layers miss cellular/proxy edge cases. Standard APIs handle them automatically. |
Example Invocations
User: "My API request is failing with a timeout"
→ Read: skills/networking-diag.md
User: "How do I use URLSession with async/await?"
→ Read: skills/networking-discipline.md
User: "I need to implement a TCP connection"
→ Read: skills/network-framework-ref.md
User: "Should I use NWConnection or NetworkConnection?"
→ Read: skills/network-framework-ref.md
User: "My app was rejected for using HTTP connections"
→ Read: skills/networking-diag.md (ATS compliance)
User: "App Store says I'm using UIWebView"
→ Invoke: networking-auditor agent (deprecated API scan)
User: "Check my networking code for deprecated APIs"
→ Invoke: networking-auditor agent
1---2name: axiom-networking-33description: Use when implementing or debugging ANY network connection, API call, or socket in an Apple app. Covers URLSession, Network.framework, NetworkConnection, connection diagnostics.4---567# Networking89**You MUST use this skill for ANY networking work including HTTP requests, WebSockets, TCP connections, or network debugging.**1011## Cursor Subagent Routing1213Delegate to the appropriate Cursor subagent when this router calls for a specialized auditor.1415## Quick Reference1617| Symptom / Task | Reference |18|----------------|-----------|19| URLSession with structured concurrency | See `skills/networking-discipline.md` |20| Network.framework anti-patterns | See `skills/networking-discipline.md` |21| Deprecated API migration | See `skills/networking-discipline.md` |22| gRPC Swift — typed RPC, streaming, `.proto` codegen (WWDC 2026) | See `skills/networking-discipline.md` |23| Pressure scenarios (reachability, sockets) | See `skills/networking-discipline.md` |24| NetworkConnection (iOS 26+) API reference | See `skills/network-framework-ref.md` |25| NWConnection (iOS 12-18) API reference | See `skills/network-framework-ref.md` |26| TLV framing, Coder protocol | See `skills/network-framework-ref.md` |27| NetworkListener, NetworkBrowser, Wi-Fi Aware | See `skills/network-framework-ref.md` |28| Connection timeouts, TLS failures | See `skills/networking-diag.md` |29| Data not arriving, connection drops | See `skills/networking-diag.md` |30| ATS / HTTP / App Store rejection | See `skills/networking-diag.md` |31| Production crisis diagnosis | See `skills/networking-diag.md` |32| NWConnection patterns (iOS 12-18) | See `skills/networking-legacy.md` |33| UDP batch, NWListener, NWBrowser | See `skills/networking-legacy.md` |34| BSD sockets → NWConnection migration | See `skills/networking-migration.md` |35| Push/calls on networks without internet (Local Push Connectivity, NEAppPushProvider) | **Use axiom-integration (skills/local-push-connectivity.md)** |36| NWConnection → NetworkConnection migration | See `skills/networking-migration.md` |37| URLSession StreamTask → NetworkConnection | See `skills/networking-migration.md` |3839## Decision Tree4041```dot42digraph networking {43 start [label="Networking task" shape=ellipse];44 what [label="What do you need?" shape=diamond];4546 start -> what;47 what -> "skills/networking-discipline.md" [label="implement patterns,\nanti-patterns,\npressure scenarios"];48 what -> "skills/network-framework-ref.md" [label="API reference\n(iOS 26+ or 12-18)"];49 what -> "skills/networking-diag.md" [label="debug connection\nfailures"];50 what -> "skills/networking-legacy.md" [label="iOS 12-18\nNWConnection patterns"];51 what -> "skills/networking-migration.md" [label="migrate from\nsockets/URLSession"];52}53```54551. URLSession with structured concurrency? → `skills/networking-discipline.md`562. Network.framework / NetworkConnection (iOS 26+)? → `skills/network-framework-ref.md`573. NWConnection (iOS 12-18)? → `skills/networking-legacy.md`584. Migrating from sockets/URLSession? → `skills/networking-migration.md`595. Connection issues / debugging? → `skills/networking-diag.md`606. Typed RPC / streaming against a service you control? → gRPC Swift (`skills/networking-discipline.md`)617. ATS / HTTP / App Store rejection for networking? → `skills/networking-diag.md` + networking-auditor628. Certificate pinning, signing API requests, encrypting payloads? → `/skill axiom-security`639. UIWebView or deprecated API rejection? → networking-auditor (Agent)6410. Want deprecated API / anti-pattern scan? → networking-auditor (Agent)6566#### Platform-specific networking67- watchOS low-level-networking limits (TN3135) → See axiom-watchos (skills/background-and-networking.md)6869## Pressure Resistance7071**When user has invested significant time in custom implementation:**7273Do NOT capitulate to sunk cost pressure. The correct approach is:74751. **Diagnose first** — Understand what's actually failing before recommending changes762. **Recommend correctly** — If standard APIs (URLSession, Network.framework) would solve the problem, say so professionally773. **Respect but don't enable** — Acknowledge their work while providing honest technical guidance7879## Critical Patterns8081**Networking** (`skills/networking-discipline.md`):82- URLSession with structured concurrency83- 8 red-flag anti-patterns (SCNetworkReachability, blocking sockets, hardcoded IPs)84- Decision tree for choosing TCP/UDP/TLS patterns85- NetworkConnection patterns (iOS 26+): TLS, UDP, TLV framing, Coder protocol86- 3 pressure scenarios with professional push-back templates87- Pre-shipping checklist8889**Network Framework Reference** (`skills/network-framework-ref.md`):90- NetworkConnection (iOS 26+): all 12 WWDC 2025 examples91- NWConnection (iOS 12-18): complete API with examples92- TLV framing, Coder protocol, NetworkListener, NetworkBrowser93- Mobility: viability, better path, Multipath TCP, NWPathMonitor94- Security: TLS, certificate pinning, cipher suites95- Performance: user-space networking, ECN, service class, TCP Fast Open9697**Diagnostics** (`skills/networking-diag.md`):98- Systematic decision tree for all connection failure types99- DNS failures, TLS certificate validation, message framing100- TCP congestion, IPv6-only cellular, VPN interference, ATS101- Production crisis scenario with professional communication templates102103**Legacy** (`skills/networking-legacy.md`):104- NWConnection with TLS (completion handlers)105- UDP batch (30% CPU reduction)106- NWListener, NWBrowser (Bonjour discovery)107108## Automated Scanning109110**Networking audit** → Delegate to the `networking-auditor` subagent or `/axiom-audit` networking (deprecated APIs, anti-patterns, and completeness gaps — transition handling, TLS coverage, connection cleanup, framework selection)111112## Anti-Rationalization113114| Thought | Reality |115|---------|---------|116| "URLSession is simple, I don't need a skill" | URLSession with structured concurrency has async/cancellation patterns. `skills/networking-discipline.md` covers them. |117| "I'll debug the connection timeout myself" | Connection failures have 8 causes (DNS, TLS, proxy, cellular). `skills/networking-diag.md` diagnoses systematically. |118| "I just need a basic HTTP request" | Even basic requests need error handling, retry, and cancellation patterns. |119| "My custom networking layer works fine" | Custom layers miss cellular/proxy edge cases. Standard APIs handle them automatically. |120121## Example Invocations122123User: "My API request is failing with a timeout"124→ Read: `skills/networking-diag.md`125126User: "How do I use URLSession with async/await?"127→ Read: `skills/networking-discipline.md`128129User: "I need to implement a TCP connection"130→ Read: `skills/network-framework-ref.md`131132User: "Should I use NWConnection or NetworkConnection?"133→ Read: `skills/network-framework-ref.md`134135User: "My app was rejected for using HTTP connections"136→ Read: `skills/networking-diag.md` (ATS compliance)137138User: "App Store says I'm using UIWebView"139→ Invoke: `networking-auditor` agent (deprecated API scan)140141User: "Check my networking code for deprecated APIs"142→ Invoke: `networking-auditor` agent