agentLabelFilter Filter

Select exchanges based on the label of the originating agent (typically a user agent string or process name) using string search or regex.

agentLabelFilter is useful when you want to scope a rule to a single client process or browser. It is one of the few filters that can look beyond the HTTP layer thanks to Fluxzy's process resolution, which makes it well suited to multi tenant captures.

When to use this filter

Use agentLabelFilter when you want to act on traffic depending on which agent emitted it. The agent label is the string Fluxzy resolved for the source of the exchange. On a transparent capture this is often the process name, in a regular proxy connection it usually mirrors the User-Agent header.

Typical situations:

Apply a custom rule only to traffic from a specific browser during cross browser testing.
Throttle a chatty background process without slowing the rest of the system.
Tag traffic from automated test runners so you can find it later in the timeline.

The filter fires on the requestHeaderReceivedFromClient scope. When you specifically want to match on the literal User-Agent header value, requestHeaderFilter with headerName: User-Agent is equally valid and more explicit.

Real world examples

Throttle a noisy desktop client

An updater process from a third party tool keeps polling and saturating your capture. Throttle just that agent so you can keep working on the actual issue.

rules:
- filter:
    typeKind: AgentLabelFilter
    pattern: updater.exe
    operation: Contains
  actions:
  - typeKind: AverageThrottleAction
    bandwidthBytesPerSeconds: 8000

Tag traffic from a specific browser during a cross browser session

Tag every exchange emitted by Firefox so you can isolate it from Chromium traffic when reviewing the capture afterwards.

rules:
- filter:
    typeKind: AgentLabelFilter
    pattern: Firefox
    operation: Contains
  actions:
  - typeKind: ApplyTagAction
    tag:
      value: source-firefox

Block headless test runner traffic

Reject any request that comes from a known headless runner used for unrelated test suites, so it does not pollute your active investigation.

rules:
- filter:
    typeKind: AgentLabelFilter
    pattern: ^(HeadlessChrome|playwright|puppeteer)$
    operation: Regex
    caseSensitive: false
  actions:
  - typeKind: RejectAction

Reference

agentLabelFilter

Description

Select exchanges according to configured source agent (user agent or process) with a regular string search.

Evaluation scope

Evaluation scope defines the timing where this filter will be applied.

requestHeaderReceivedFromClient This scope occurs the moment fluxzy parsed the request header receiveid from client

YAML configuration name

agentLabelFilter

Settings

The following table describes the customizable properties available for this filter:

Property	Type	Description	DefaultValue
pattern	string	The string pattern to search
operation	exact \| contains \| startsWith \| endsWith \| regex	The search operation performed	contains
caseSensitive	boolean	true if the Search should be case sensitive	false
inverted	boolean	Negate the filter result	false

Example of usage

The following examples apply a comment to the filtered exchange

Retains only exchanges with the exact agent label.

rules:
- filter:
    typeKind: AgentLabelFilter
    pattern: Chrome
    operation: Contains
  actions:
  - typeKind: ApplyCommentAction
    comment: filter was applied

.NET reference

View definition of AgentLabelFilter for .NET integration.

Frequently asked questions

Where does the agent label come from?

Fluxzy fills the label from the most reliable source available. On Windows and macOS it can be the originating process when transparent capture is on, otherwise it falls back to the User-Agent header.

Is the search case sensitive?

No by default. Set caseSensitive to true if you need to distinguish between agents that differ only in casing.

What is the difference with requestHeaderFilter?

requestHeaderFilter looks at one raw HTTP header, while agentLabelFilter looks at the resolved agent label which may come from outside the HTTP request, for example from the process table during transparent capture.

Can I combine it with other filters?

Yes. Use filterCollection to combine agentLabelFilter with a host or path filter for highly targeted rules.

Learn more about Fluxzy rules

Rule file syntax reference Importing YAML rules into Fluxzy Desktop Using rule files with Fluxzy CLI

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