Network Conditions

Simulate slow networks with latency presets applied to proxied HTTP and HTTPS requests.

Network Conditions

Network Conditions adds artificial latency to matching requests using named presets modeled after Apple’s Network Link Conditioner. Use it to test loading states, timeout handling, and degraded-network UX without leaving Rockxy.

Phase 1 simulates added request-start latency only. Bandwidth shaping, packet loss, and jitter are planned for a future release.

Entry Points

Action	How to Access
Network Conditions window	Tools > Network Conditions… (Cmd+Opt+N)
Quick-create from request	Right-click a captured request > Tools > Network Conditions…
Quick-create from domain	Right-click a domain in the sidebar > Tools > Network Conditions

Presets

Each preset maps to a fixed latency value applied before the request is forwarded upstream:

Preset	Latency	Use Case
3G	400 ms	Mobile fallback testing
EDGE	850 ms	Extreme slow-network edge cases
LTE	50 ms	Typical mobile latency
Very Bad Network	2000 ms	Timeout and retry logic
WiFi	2 ms	Baseline with minimal overhead
Custom	User-defined	Specific latency requirements

One-Active Enforcement

Only one Network Conditions rule can be active at a time. When you enable a rule, all other Network Conditions rules are automatically disabled. This applies across both the dedicated window and the general Rules list.

A warning banner appears in the Network Conditions window if multiple rules are somehow enabled simultaneously.

Window Layout

The Network Conditions window (880 x 480) follows the standard Rockxy tool-window layout:

1. Inline Toolbar — Disable All button, Search field, Add Rule button
2. Info Bar — help text describing the feature
3. Table — columns for Enabled (toggle), Name, Scope (URL pattern), Profile (preset name), Latency (ms), and Status (Active / Inactive / Conflict)
4. Bottom Bar — Add (+) and Remove (-) buttons, rule count

Creating a Network Condition

From the dedicated window

1. Open Tools > Network Conditions… or press Cmd+Opt+N.
2. Click Add Rule or the + button.
3. Enter a rule name and URL pattern (Exact Path, Subpaths, or Regex).
4. Select a preset or choose Custom and enter a latency value in milliseconds.
5. Click Add Rule.

From a captured request (quick-create)

1. Right-click any request in the traffic list.
2. Choose Tools > Network Conditions… from the context menu.
3. The edit sheet opens pre-filled with the request’s host and path.
4. Select a preset and click Add Rule.

From the sidebar (domain quick-create)

1. Right-click any domain in the sidebar.
2. Choose Tools > Network Conditions from the context menu.
3. The edit sheet opens pre-filled with the domain as a subpath match.

How It Works

Network Conditions rules use the networkCondition action type internally, separate from generic throttle rules. When a matching request arrives:

1. The rule engine evaluates rules in order and finds the first matching enabled rule.
2. If it is a Network Conditions rule, the proxy holds the request for the configured latency before forwarding it upstream.
3. The delay applies to the request initiation phase — response streaming is not paced.

HTTPS requests are delayed after TLS interception, so the delay applies to the decrypted HTTP traffic inside the tunnel, not to the CONNECT handshake.

Persistence

Network Conditions rules are persisted alongside all other rules in ~/Library/Application Support/Rockxy/rules.json. They survive app restarts and can be exported/imported through the standard rule system.

Limitations

• Latency only — no bandwidth shaping, packet loss, or jitter simulation in Phase 1
• Request-start delay — the delay is applied before forwarding; response body streaming is not paced
• WebSocket frames — latency applies to the initial HTTP upgrade request, not to individual WebSocket frames after the connection is established
• One active rule — only one Network Conditions rule can be active at a time