Capturing traffic¶

Quena is a proxy: applications send their requests to Quena, and Quena forwards them to the server (or to the next proxy) and records both directions.

Start and stop¶

The capture switch at the left of the toolbar shows Capturing or Paused. Click it, press F12, use Capture → Capture Traffic, or type start / stop in the command field.
While the system proxy is being changed, the switch shows Starting… or Stopping….
Stopping the capture also closes open client connections, tunnels and WebSockets (after the request in flight), so nothing more is recorded.
Settings → General → Capture traffic on startup (on by default) decides whether Quena captures right after it starts.

Listen port¶

Quena listens on port 8866 by default (127.0.0.1:8866). Change it in Settings → Connections → Listen port. The status bar shows the address Quena listens on.

System proxy¶

With Settings → Connections → Act as system proxy while capturing (on by default), Quena registers itself as the system proxy while it captures, so browsers and most desktop applications send their traffic through it automatically.

Platform	What Quena changes
macOS	the proxy of all network services (changed at once)
Windows	the proxy of the current user
Linux	the GNOME or KDE Plasma proxy setting that browsers follow

The previous proxy setting is saved and restored when you quit — and, if Quena ever crashes, at the next start. On Windows, logging off or shutting down while Quena runs restores it as well.

Tools that ignore the system proxy¶

Command-line tools usually do not follow desktop proxy settings. Point them at Quena explicitly:

curl -x http://127.0.0.1:8866 https://example.com

export HTTP_PROXY=http://127.0.0.1:8866
export HTTPS_PROXY=http://127.0.0.1:8866

For HTTPS, such tools must also trust Quena's root certificate — see HTTPS and devices.

Upstream proxy and PAC¶

In a corporate network, Quena forwards to the proxy you used before. The options are in Settings → Connections:

Option	Meaning
Chain to the previous system proxy (upstream gateway)	On by default: the proxy that was active before Quena took over becomes Quena's upstream.
Manual upstream proxy	`host:port` of a proxy to use instead. A manual upstream overrides PAC.
Bypass upstream for	Hosts that go direct instead of through the upstream. Default: `localhost;127.0.0.1;::1;*.local`.
Use the system proxy auto-config (PAC) script	On by default: evaluate the PAC script the OS proxy settings point to.
PAC URL or file	A PAC script of your own (`http://…/proxy.pac`, `file://…` or a local path). Empty means the system PAC.

PAC notes:

FindProxyForURL(url, host) is evaluated once per host and cached.
https:// PAC URLs are not fetched — download the file and enter its path instead.
The download must finish within 15 s and be at most 1 MB. A script that hangs or fails falls back to DIRECT for that lookup, so a broken PAC file never stalls the app.

If the upstream proxy asks for authentication (407), Quena can answer it — see Automatic authentication.

Remote computers and devices¶

Remote connections are off by default. To capture a phone, a tablet, a VM or another computer:

Enable Settings → Connections → Allow remote computers to connect (or click the button in Capture → Connect Device…).
Optionally restrict who may connect with Allowed remote networks: CIDR ranges or addresses separated by ; (e.g. 192.168.1.0/24; 10.0.0.5). Empty means local subnets.
Configure the device to use your computer's address and port 8866 as its HTTP proxy.

Capture → Connect Device… walks you through this with a QR code — see Phones, tablets and VMs.

Which application sent a request¶

Quena attributes each request to the process that sent it. The name appears in the Process column (hidden by default in the Quena layout, visible in Classic) and in the inspector header.

Platform	Process attribution
macOS	✅
Windows	✅
Linux	✅ for processes of your own user (via `/proc`)

Use it to narrow the list:

Status bar → process scope: All processes, Browsers only, Non-browsers or Remote clients.
Filters → Client Process: the same choices, plus Show only traffic from and Hide traffic from (e.g. chrome; java).
Right-click a session → Filter Now → Hide this Process / Show only this Process.
Right-click → Select → Same Process.

Streaming and storage¶

Stream (toolbar toggle, on by default) passes response bodies to the client as they arrive. Turned off, Quena buffers the response first.
Keep (toolbar button with the history icon) keeps only the newest 100, 200, 500, 1,000 or 10,000 sessions; the default is Keep all sessions.
Bodies are stored on disk, not in memory, so large downloads do not fill the RAM. The status bar shows how much the capture uses and how much disk space is free. The limits are in Settings → Bodies & Storage; see Settings.