Ferret

Modern HTTP inspector for Flutter — zero setup, production-safe, raw visibility.

See everything. Ship nothing you didn't mean to.

Ferret captures Dio, package:http, and dart:io traffic into a Material 3 inspector: floating bubble, call list, raw detail, and cURL / HAR export.

Why Ferret

Most Flutter HTTP inspectors are debug-only. They are not designed to run safely in release builds.

Ferret is different:

	Typical inspectors	Ferret
Debug / profile	On	On by default
Release builds	Usually unavailable or unsafe	Off by default (true no-op)
Opt-in release mode	Rare / not supported	Supported via `enableInRelease: true`
Release warning	Often missing	Always on — console banner + permanent red tag (cannot be disabled)
Data in-app	Often masked	Full raw bodies & headers
Setup	Wire every client	`Ferret.install()` + `builder: Ferret.builder`

Install

dependencies:
  ferret: ^0.1.0

flutter pub get

Quick start

import 'package:ferret/ferret.dart';
import 'package:flutter/material.dart';

void main() {
  Ferret.install();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      navigatorKey: Ferret.navigatorKey,
      builder: Ferret.builder, // floating bubble (center-right by default)
      home: const HomePage(),
    );
  }
}

Capture traffic

// Dio — recommended
final dio = Ferret.createDio();
// or attach to an existing instance:
dio.interceptors.add(Ferret.dioInterceptor);

// package:http
final client = Ferret.wrapClient(http.Client());

// dart:io HttpClient — captured automatically after install (mobile/desktop)

Platform support

Platform	Dio	package:http	dart:io
Android / iOS / macOS / Windows / Linux	✓	✓	✓
Web	✓	✓	— (not available)

On web, use Ferret.createDio() or Ferret.wrapClient() — the inspector UI and HAR/cURL export work the same.

Configuration

Ferret.install(
  config: const FerretConfig(
    enabled: true,              // master switch (debug/profile)
    enableInRelease: false,     // set true only when you intentionally need release
    maxEntries: 500,            // ring buffer size
    captureBody: true,
    clients: {
      HttpClientType.dio,
      HttpClientType.http,
      HttpClientType.dartIo,
    },
    slowThreshold: Duration(seconds: 2),
  ),
);

Debug and release behavior

Mode	Behavior
Debug / Profile	On when `enabled: true` (default)
Release	Fully off unless `enableInRelease: true`
Release + `enableInRelease: true`	On, with a loud console warning and a permanent red FERRET ACTIVE tag

When disabled, Ferret does not intercept, store, or render anything.

Floating bubble

Circular count button, default position center-right (drag to move).
Flashes red briefly when a new failed call arrives.
Tap opens the full inspector.
Hidden while the inspector is open.

Features

Floating count button → full inspector
Call list with method, path, host, status, duration, size
Detail tabs: Overview · Request · Response · Error
Search & filters (method, failed, slow)
Copy as cURL (per call)
Share / copy session as HAR

Repository

https://github.com/darkmintis/ferret

Example

git clone https://github.com/darkmintis/ferret.git
cd ferret
fvm use 3.44.1
cd example
flutter run

API surface

Ferret.install(config: ...);
Ferret.navigatorKey
Ferret.builder
Ferret.createDio([options])
Ferret.dioInterceptor
Ferret.wrapClient(client)
Ferret.openDashboard()
Ferret.clear()
Ferret.toCurl(entry)
Ferret.toHar(redact: false)
Ferret.shareSession(redact: false)
Ferret.shareCurl(entry)
Ferret.isActive

Requirements

Flutter >=3.44.0
Dart ^3.12.1