Independent Download Manager and IDM Research Notes

An independently implemented Windows download manager. It is not affiliated with Internet Download Manager and does not use IDM code, artwork, or branding. The interface uses a familiar download-manager layout, with its own styling.

This repository contains the app and Chrome extension source, plus static reverse-engineering notes about an installed IDM version. It does not include IDM binaries, extension packages, copied assets, or decompiled IDM code. The research notes describe observations and limitations; they are not an IDM implementation specification or proof of runtime behavior.

Current features

• Add direct HTTP and HTTPS URLs; newly added downloads start automatically when the sequential queue is idle. Queued downloads restored at startup also resume automatically; intentionally paused downloads remain paused.
• Choose a destination folder; existing filenames are not overwritten.
• View all, active, queued, unfinished, and completed downloads.
• Automatically group common file extensions into categories.
• Show download state, known file size, progress, transfer rate, and estimated time remaining while a transfer is active.
• Pause, resume, retry failed downloads, cancel selected jobs, and stop queued or active work.
• Keep a .part file on pause and attempt to resume using HTTP range requests. Resume depends on server support; if the server does not support ranges, the transfer restarts from the beginning.
• Open completed files or their containing folder.
• Remove completed entries from the list without deleting the downloaded files.
• Report transfer errors in the download list.
• Restore the download list at startup and pause an active transfer cleanly on exit so its partial file can be resumed later.

The saved queue is stored in the current Windows user's local application data folder. It contains the URLs and destination paths entered by the user; URLs can include private query tokens, so the file should be treated as personal data. Categorization is based on filename extensions. This build supports direct file URLs. It does not support segmented downloads, download authentication/cookie management, scheduler automation, a media grabber, or streaming/video quality selection. These are separate features that require implementation and testing, not just UI controls.

The independent Chrome extension in chrome-extension/README.md can send direct HTTP(S) URLs to the desktop app through a per-user Chrome Native Messaging host and a same-user named pipe. Media scans remain user-triggered and support only direct media-file URLs. The extension also offers new browser HTTP(S) downloads to the desktop app by pausing the Chrome download and prompting the user; fast downloads may complete before Chrome reports them. This handoff is best-effort, and browser cookies/authentication are not transferred. Segmented downloads and streaming quality detection are not implemented. Register the host with chrome-extension\install-native-host.ps1 after building or publishing.

Run

From PowerShell in this directory:

dotnet run -c Release

Build and publish

dotnet build -c Release
$publishDir = Join-Path $PWD.Path 'bin\Release\net8.0-windows\win-x64\publish\BridgeReady\'
dotnet publish DownloadManager.csproj -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true "-p:PublishDir=$publishDir"
dotnet publish native-host\NativeMessagingHost.csproj -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true "-p:PublishDir=$publishDir"
.\chrome-extension\install-native-host.ps1

The desktop app and native host are published side-by-side under bin\Release\net8.0-windows\win-x64\publish\BridgeReady\. The installer script registers the native host for the current Windows user; restart Chrome after loading the extension and installing the host.

Check the Chrome extension

Run its dependency-free tests with Node.js:

node --test chrome-extension\tests\service-worker.test.mjs