One tool to trace them all

The cross-platform HTTP debugger to view, record and alter your HTTP flows, in one go debugging session or within automated workflow.

Accelerate how you debug http streams.

A fully-featured HTTP debugger designed to speed up your testing and web development workflow. Based on an open-source HTTP engine, the free community edition gives you unlimited access to all features including: mocking, breakpoints, rewriting, debugging, script injection, recording, and so many more.
Simply Exhaustive
Captures everything from PCAPNG with SSLKEYLOG to deciphered HTTP1.1/H2/Websocket exchanges.
Any Platform
Runs on Windows, macOS, linux and collects traffic for any remote devices including iOS and Android.
Full debugging capabilities
Halt, edit, resubmit, replay, mock, redirect, spoof, ... Fluxzy has everything you expect from an HTTP debugger.
Built for observability
Fast throughput, always streaming by design, every processing block of fluxzy engine has been created to produce minimal overhead.
Codeless traffic alteration
Express simple and declarative directives with YAML files and let Fluxzy connect them to the 100+ built-in filters, actions, and rules.
Live capture
Deflect OS trafic directly to fluxzy or run and hook existing browsers and terminals. Supported environments are Windows, macOS and Gnome based application.
Check all available features or download.

Fluxzy Desktop

Enhance your debugging journey with a modern and intuitive HTTP debugger.
Get for free a complete and unlimited version of Fluxzy Desktop Community Edition
with no credit card required.

Ready to use alteration directives

Shape web streams in a simple, straightforward and declarative way

This is how you can add a suffix to any user agent header passing through fluxzy.

  update-user-agent.yaml 
rules:
  - filter: 
      typeKind: AnyFilter        
    action : 
      typeKind: UpdateRequestHeaderAction
      headerName: user-agent
      # previous reference the original value of the user-agent header
      headerValue: "{{previous}} - Relayed by fluxzy"

Test this command with Fluxzy Desktop or with the CLI with the following command. 

fluxzy start -r update-user-agent.yaml

Download Fluxzy CLI or pull the docker image to test this example. Learn more about rule file

For example, to remove a cache from a HTTP directive, we need a combination of several header alteration. You can take advantage of the built-in action RemoveCacheAction to do this with a single directive.

  remove-cache-command.yaml 
rules:
  - filter: 
      typeKind: HostFilter
      pattern: google.com
      operation: endsWith
    action : 
      # This action remove any cache directive from request and response header
      typeKind: RemoveCacheAction

Test this command with Fluxzy Desktop or with the CLI with the following command. 

fluxzy start -r remove-cache-command.yaml

Download Fluxzy CLI or pull the docker image to test this example. Learn more about rule file

Add a comment to any POST request.

  set-comment-command.yaml 
rules:
  - filter: 
      typeKind: HostFilter
      pattern: google.com
      operation: endsWith
    actions: 
      # Add a comment to any exchange to google.com
      - typeKind: ApplyCommentAction
        comment: Hello fluxzy

Test this command with Fluxzy Desktop or with the CLI with the following command. 

fluxzy start -r set-comment-command.yaml

Download Fluxzy CLI or pull the docker image to test this example. Learn more about rule file

Add a client certificate to ongoing exchanges.

  client-certificate.yaml 
rules:
    - filter: 
        typeKind: HostFilter
        pattern: mtls.domain.com
    - action: 
        typeKind: SetClientCertificateAction
        clientCertificate: 
        pkcs12File: certificate.pfx
        # password is taken from environment variable CERT_PASSWORD
        pkcs12Password: ${env.CERT_PASSWORD} 
        retrieveMode: FromPkcs12

Test this command with Fluxzy Desktop or with the CLI with the following command. 

fluxzy start -r client-certificate.yaml

Download Fluxzy CLI or pull the docker image to test this example. Learn more about rule file

The following sample uses build-in variables to save to file any bearer token traversing fluxzy

  capture-bearer-token.yaml 
rules:
  - filter: 
      typeKind: FilterCollection # can be multiple combination of filters
      operation: and
      children:
         - typeKind: postFilter # select only post requests 
         - typeKind: requestHeaderFilter
           headerName: authorization # select only request with authorization header
           operation: regex
           pattern: "Bearer (?<BEARER_TOKEN>.*)" # A named regex instructs fluxzy
                                                 # to extract token from authorization
                                                 # header into the variable BEARER_TOKEN
    action : 
      # Write the token on file 
      typeKind: FileAppendAction # Append the token to the file
      filename: token-file.txt # save the token to token-file.txt
      text: "${authority.host} --> ${user.BEARER_TOKEN}\r\n"  # user.BEARER_TOKEN retrieves 
                                            # the previously captured variables 
      runScope: RequestHeaderReceivedFromClient  # run the action when the request header 
                                                 # is received from client

Test this command with Fluxzy Desktop or with the CLI with the following command. 

fluxzy start -r capture-bearer-token.yaml

Download Fluxzy CLI or pull the docker image to test this example. Learn more about rule file

Browse and search all filter and action directives to learn the many ways you can transform your HTTP streams.

Integrate with you .NET app

Access all Fluxzy features, from request recording to advanced traffic alteration, in your own code with the open-source Fluxzy NuGet packages. View the documentation or visit the official repository.