Mac DM

A fast, IDM-style download manager for macOS — multi-connection segmented downloads, resume, a Chrome capture extension, HLS/stream saving, and YouTube support via yt-dlp. CLI, GUI, and browser all drive one shared engine.

English | 한국어

Built for personal use. You are responsible for complying with the terms of service and copyright of any site you download from. See Responsible use.

Features

• Segmented downloads — splits a file into N parallel HTTP Range connections (default 8) for higher throughput; automatically falls back to a single connection when the server doesn't support ranges.
• Resume — interrupt any download (Ctrl-C, pause, crash, reboot) and it continues from where it left off. Restart-safe: the daemon rebuilds its queue from disk and finishes in-flight jobs.
• Per-connection progress (IDM-style) — see each connection's own bar and percentage in the GUI, or with dm show <id> in the terminal.
• Background daemon — the engine runs as a headless daemon over a local Unix socket. CLI, GUI, and the Chrome extension are all thin clients of the same daemon, so a download added anywhere shows up everywhere.
• Queue, concurrency & rate limiting — cap simultaneous downloads (dm concurrent N) and total speed (dm limit 2M), shared across all jobs.
• Chrome capture — an extension intercepts browser downloads and hands them to the daemon (passing cookies/referer for authenticated files).
• HLS / streams — detects .m3u8 and downloads + merges with ffmpeg.
• YouTube & 1000+ sites — routes streaming-site URLs to yt-dlp, picks the best video+audio, and merges to a QuickTime-friendly MP4. Optional quality selection (auto, 1080p, 720p, …).
• Categories — downloads auto-sort into video / audio / image / doc / archive / app, with a sidebar filter in the GUI.

Architecture

Chrome extension (TS) ─┐
GUI (Tauri)           ─┼─►  daemon (Go, ~/.mac-dm/dm.sock)  ─►  download engine
CLI (dm)              ─┘        queue · concurrency · rate         Range split / resume
                               limit · restart recovery           HLS (ffmpeg) / yt-dlp

The engine is a standalone daemon, not embedded in the GUI or the extension. Every client attaches to the same daemon over a private, user-only Unix socket (~/.mac-dm/dm.sock), so state is consistent no matter how a download was started.

Requirements

• macOS
• Runtime tools (installed automatically by install.sh via Homebrew):
  • ffmpeg — HLS merging & MP4 remux
  • yt-dlp — streaming-site downloads
• To build from source:
  • Go 1.23+ (engine, CLI, native host)
  • Rust + Node.js (GUI, via Tauri 2)
  • Google Chrome (for the capture extension)

Install (from source)

git clone https://github.com/Gwani-28/mac-dm.git
cd mac-dm
./scripts/install.sh

install.sh builds dm and dm-host into ~/.mac-dm/bin, ensures ffmpeg/yt-dlp are present, builds the GUI (if Rust/Node are available) and copies MacDM.app to /Applications, and registers the Chrome native messaging host.

Then load the Chrome extension:

1. Open chrome://extensions
2. Enable Developer mode
3. Load unpacked → select the extension/ folder

Uninstall with ./scripts/uninstall.sh (add --purge to also remove job history and logs).

Usage

CLI

dm add <URL>                 # queue a download (auto-starts the daemon)
dm add -q 1080p <URL>        # pick a video quality (streaming sites)
dm list                      # progress & speed for all jobs
dm show <ID>                 # per-connection bars (IDM-style)
dm pause / resume / cancel / rm <ID>
dm limit 2M | off            # global speed cap
dm concurrent 3              # max simultaneous downloads
dm daemon start | stop | status
dm download <URL>            # one-off download without the daemon
dm host install              # register the Chrome native messaging host

GUI

Launch MacDM.app. Paste a URL, pick a quality if it's a video, and manage everything (pause/resume/cancel, per-connection progress, category filter, speed/concurrency settings) from the window. "Reveal in Finder" on completed files.

Chrome

With the extension loaded, downloads are captured automatically and sent to Mac DM. On a video-site page (YouTube, etc.), click the extension → Download this video. Right-click any link → Download with Mac DM.

How it works

• Merge without a merge step. Instead of downloading N chunk files and concatenating them, the engine pre-allocates the full-size .part file and each worker WriteAts its own byte range. Re-downloading a byte always lands at the same offset, so retries and resumes are idempotent and there is no "failed mid-merge" state.
• Resume is a single number. Each segment records how many bytes it has written; the metadata is flushed every second and on interrupt, and never runs ahead of what's on disk. If the server file changed (size/ETag mismatch), the resume is discarded rather than producing a half-old/half-new file.
• Streaming split differs. YouTube isn't a single file — it's separate, signed DASH video/audio streams, so it goes through yt-dlp (parallel fragments) rather than HTTP Range. ffmpeg merges them into MP4.

Development

go build ./...        # engine, CLI, native host
go test ./...         # unit + integration tests
cd gui && npx @tauri-apps/cli dev    # run the GUI in dev mode
cd extension && npx tsc              # compile the extension TypeScript

Layout:

Path	What
cmd/dm	CLI entry point
cmd/dm-host	Chrome native messaging host
internal/downloader	segmented download, resume, routing
internal/daemon	daemon, queue/scheduler, local HTTP API
internal/httpclient / store / ratelimit	probing, resume metadata, token bucket
internal/hls / internal/ytdl	ffmpeg (HLS) and yt-dlp (streaming) backends
gui/	Tauri app (vanilla HTML/JS/CSS front-end, zero JS libs)
extension/	Chrome MV3 extension (TypeScript)

The Go side has zero third-party module dependencies — standard library only. External tools (ffmpeg, yt-dlp) are invoked as subprocesses.

Responsible use

This is a general-purpose download manager. When it downloads from streaming sites via yt-dlp, you are responsible for respecting each site's terms of service and applicable copyright law — use it only for content you have the right to download (e.g. your own uploads, or material licensed for download). It does not circumvent DRM or access protected content.

Project status & roadmap

Actively developed. Every push runs go build / go vet / go test and an extension type-check in CI. See the roadmap for what's next (code signing, prebuilt release binaries, a Homebrew tap, checksum verification, GUI localization) and the changelog for release history.

Community

• Contributing guide
• Code of Conduct
• Security policy
• Ideas & bugs → open an issue

License

MIT © 2026 Gwani-28

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🇰🇷 한국어 문서: README.ko.md