RelayCraft
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The AI-Powered Network Debugging Tool Crafted for Modern Developers

Control your network flows with intelligent interception, dynamic modification, and automation in a modern, lightweight desktop app.

RelayCraft Interface Preview

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AI Powered

Create rules with natural language, analyze requests intelligently, boosting efficiency by 10x.

Modern UI

Designed for developers with a modern interface, saying goodbye to outdated tool aesthetics.

Free & Open Source

Open sourced under GPL v3, permanently free for individual developers.

Cross Platform

Supports Windows, macOS, Linux. One tool for all platforms.

Traffic Monitor

Capture Real-time, Clear at a Glance

  • High-performance traffic list, supporting massive requests
  • Rule hit annotation, clear debugging status
  • Complete request/response details, JSON syntax highlighting
  • Multiple export formats (HAR, cURL, proprietary format)
Explore Monitor

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Rules Engine

Visual Rule Configuration, Goodbye Complex Scripts

  • 6 Rule Types: Mock Response, Map Local, Map Remote, Rewrite Header, Network Simulate, Block Request
  • 4 Match Modes: Contains, Exact, Regex, Wildcard
  • Real-time match testing, instant verification
  • Support grouping, batch import/export
Rules Guide

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AI Assistant

AI-Enhanced, Debugging Made Simple

  • Natural language rule creation: "Block all Google Analytics requests"
  • Intelligent request analysis: One-click interpretation, discover potential issues
  • Context awareness: AI understands your current operation context
  • Ctrl+K global summon, always ready
AI Features

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Breakpoints

Intercept, Modify, Release, Full Control

  • Domain-level breakpoints, one-click interception
  • Breakpoint management panel, batch or individual release
  • Modify request content and continue sending
  • Perfect support for security testing and exception simulation
Debugging Guide

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Request Composer

Built-in Composer, Rapid API Verification

  • Support various HTTP methods
  • Jump from capture to edit and resend
  • One-click cURL import
  • Instant response display
Composer Docs

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Scripting

Rules Not Enough? Scripts to the Rescue

  • Powerful scripting based on mitmproxy
  • Built-in code editor, write and use instantly
  • Rules are a subset of scripts, seamless progression
  • Access full mitmproxy API for limitless customization
Scripting API

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Certificates

One-click Install, Zero Threshold HTTPS Capture

  • Intelligent detection of certificate installation status
  • One-click system certificate installation
  • Detailed manual installation guide (including mobile)
  • Support certificate regeneration
Setup Certificates

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Security & Privacy: Your Data, Yours Alone

Fully Offline

All core features work offline. Your traffic data never leaves your device.

No Account Required

No registration, no login, no subscription. Download and use instantly.

Local Storage

Rules, configs, and capture data are stored locally. You have full control.

Local AI Support

Supports local LLMs like Ollama. Sensitive data stays on your machine.

Open Source & Auditable

GPL v3 licensed. Code is transparent, verifiable, and backdoor-free.

Zero Telemetry

No hidden data collection, user behavior analytics, or background telemetry.

Why Choose RelayCraft?

FeatureRelayCraftCharlesFiddlerProxyman
PriceFree Open Source$50FreemiumSubscription
AI CapableFull SupportNoNoNo
Modern UIExcellentFairFairExcellent
Cross PlatformWin/Mac/LinuxWin/MacWinMac
Visual RulesCompleteBasicBasicBasic

Who is using RelayCraft?

Frontend Devs

Mock APIs, Debug interfaces, Solve CORS issues

Mobile Devs

Traffic analysis, Weak network simulation, App request debugging

QA Engineers

Exception simulation, Interface verification, Issue reproduction

Security Researchers

Request tampering, Vulnerability analysis, Protocol research

Start in 3 Steps

1

Download & Install

Choose your platform, one-click install

2

Install Cert

Click 'One-click Install' to complete HTTPS config

3

Start Capture

Start proxy, traffic captured automatically

Open Source Driven

Code is open source, transparent and auditable
Welcome contributions of code and plugins
Join our active developer community