MacGet

Note: MacGet is not affiliated with or endorsed by Tonec Inc. or Internet Download Manager. It's an independent free alternative.

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Why another download manager?

Most "multi-threaded" download managers naively open as many TCP connections as you let them. Modern CDNs treat that as leech behavior — they TCP-RST connections after a few bytes, throttle your IP, or 403 your requests. The result: more threads = slower downloads, sometimes failures.

MacGet's engine discovers each host's true capacity at runtime and adapts:

• Adaptive demotion. When ≥4 chunk attempts fail without progress in a 10-second window (i.e., the host is rejecting parallelism), the engine halves its worker count, cancels the lowest-progress chunks, and continues. Repeats until stable.
• Per-host parallelism memory. The learned cap is persisted to ~/Library/Application Support/Macget/host_caps.json. Future downloads from that host start at the right level — no rediscovery cost.
• Stagger on spawn. Workers spawn 100 ms apart so anti-abuse middleboxes see a steady stream rather than a SYN burst from one IP.
• App Nap defense. A ProcessInfo activity is held while any download is running, so macOS doesn't throttle CPU/network when you switch apps or minimize the window.
• Smart retry classification. Permanent failures (401/403/404/410/451, range refusals, malformed responses) fail fast. Transient errors (-1005 mid-stream RSTs, -1017 server-side stream kills, 5xx) retry with exponential backoff inside a hard global cap.

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Features

• Up to 16 parallel HTTP-Range chunks per file (industry-standard cap; aria2 uses the same).
• Pause / resume / cancel with state that survives app restarts.
• Persistent queue — close the app, reopen, in-flight downloads continue.
• Drag-and-drop, clipboard watch, NSServices — paste a URL or drop a file from anywhere.
• Live thread adjustment while a download is running (subject to host caps).
• Built-in book catalogs — browse and search Project Gutenberg and the Internet Archive from inside the app, then send a book straight to the queue. Add any OPDS feed too, including your own Calibre server.
• BitTorrent — magnet links and .torrent files download in the same queue as everything else, several at once. Off by default; seeding is bounded by a ratio and time limit you control. MacGet doesn't search for or index torrents.
• Auto-updates via Sparkle — enabled and signature-verified (details).
• Native SwiftUI with proper @Observable view models and an actor-based engine.
• MIT licensed. No ads, no telemetry, no payments.

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Install

Homebrew (recommended)

brew install --cask suryansh-codes2209/macget/macget

Requires macOS 26.4 or later on Apple silicon. The cask removes the quarantine attribute after install, so there is no Gatekeeper prompt and no "Open Anyway" step.

From a release DMG (when v1 ships)

1. Download macget.dmg from the Releases page.
2. Open the DMG, drag Macget to Applications.
3. Launch from Applications.

Minimum macOS: 26.4 Tahoe.

First launch on macOS

Macget is currently distributed free and un-notarized (no paid Apple Developer account). On first launch macOS Gatekeeper will say "Macget can't be opened because Apple cannot check it for malicious software." This is expected — to open it:

1. Click Done on the warning.
2. Open System Settings → Privacy & Security, scroll down, and click Open Anyway next to Macget.
3. Confirm once more — Macget opens normally from then on.

Power-user one-liner instead of the steps above:

xattr -dr com.apple.quarantine /Applications/Macget.app

Auto-updates (via Sparkle) install smoothly after this one-time step.

From source

git clone https://github.com/Suryansh-Codes2209/Macget.git
cd Macget
open Macget.xcodeproj

Then in Xcode: ⌘R to run, ⌘U to test. The .xcodeproj is committed and Sparkle is gated behind #if canImport(Sparkle), so the app builds and runs without any extra setup.

To enable auto-updates (optional): File → Add Package Dependencies… → https://github.com/sparkle-project/Sparkle (≥ 2.6.0).

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Updates

After the first install you don't re-download MacGet from this page — it keeps itself current with Sparkle, the standard auto-update framework for apps distributed outside the Mac App Store.

• Automatic. On launch MacGet quietly checks its appcast feed on a schedule. When a newer version is published it offers to download and install it.
• Manual. Any time, choose MacGet → Check for Updates… from the menu bar.
• Verified. Every update is signed with an EdDSA key; MacGet checks the signature before installing, so a tampered or corrupt download is rejected. This is independent of Apple notarization — updates are trustworthy even on the free, un-notarized build.

Sparkle is gated behind #if canImport(Sparkle). Auto-updates are active in release builds that bundle the Sparkle SPM dependency; a from-source build without it falls back to a Check for Updates… menu item that explains the dependency is missing.

Maintainers — publishing an update: cut a release (see Release a DMG), then regenerate the signed feed with Sparkle/bin/generate_appcast site/ and push site/. GitHub Pages serves site/appcast.xml at the SUFeedURL above. The EdDSA private signing key lives only in your login Keychain ("Private key for signing Sparkle updates") — back it up offline, or you can never sign another update for existing installs.

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Architecture

The download engine is the heart of the app; everything else is glue. Top-level flow for one download:

Probe (HEAD → GET Range:0-0 fallback) → Disk-space check → Plan chunks
       → Open sparse partial file → Spawn workers (staggered)
       → Stream over URLSession → 64 KB writes through FileWriter actor
       → Demote on rapid failures → Finalize → Move into place

Key types (under Macget/Engine/):

Type	Role
DownloadEngine	Top-level actor. Owns all coordinators, schedules per maxConcurrentDownloads, emits an AsyncStream<EngineEvent> to the UI.
DownloadCoordinator	Per-download actor. Probes, plans, spawns workers, runs the orchestration loop, demotes on rapid failures.
ChunkWorker	One HTTP-Range request, one attempt. Streams data via an AsyncThrowingStream bridge over URLSessionDataDelegate.
ChunkPlanner / ChunkSplitter	Static planning: split bytes into ≥ 64 KB chunks, clamped to Download.maxThreadCount.
FileWriter	Actor wrapping a FileHandle. Serializes positional writes so concurrent chunks don't race.
RangeProbe	HEAD then ranged-GET fallback. Records Content-Length, Accept-Ranges, ETag, Last-Modified.
SpeedMeter	3-second rolling-window throughput + ETA.
HostCapStore	Persistent per-host parallelism memory. Caps ratchet downward only.
URLSessionFactory.shared	Single process-wide URLSession — responsiveData QoS, extended background idle mode, httpMaximumConnectionsPerHost = 16.

For deeper detail, read docs/architecture.md — the full engine walkthrough, object graph, and resume semantics. CLAUDE.md holds the day-to-day conventions for contributors.

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Project layout

Macget/
├── Macget/                       ← Swift sources
│   ├── App/                      ← AppDelegate, AppEnvironment
│   ├── Models/                   ← Download, Chunk, Status, Settings
│   ├── Persistence/              ← DownloadStore (queue.json), HostCapStore (host_caps.json)
│   ├── Engine/                   ← ★ multi-threaded download engine
│   ├── Services/                 ← Clipboard watcher, filename resolver, disk check
│   │   └── Catalog/              ← OPDS parser/client, catalog list (catalogs.json)
│   ├── Updater/                  ← Sparkle wrapper (gated)
│   ├── ViewModels/               ← @MainActor @Observable
│   ├── Views/                    ← SwiftUI
│   ├── Resources/                ← Info.plist, entitlements, Assets.xcassets, Branding/
│   └── Supporting/               ← os.Logger
├── MacgetTests/                  ← XCTest suites (46 tests)
├── MacgetUITests/                ← XCUITest harness
├── scripts/release.sh            ← build → DMG → notarize → staple
├── site/index.html               ← landing page (deploy via GitHub Pages)
├── .github/workflows/ci.yml      ← CI: build + test on push/PR
├── CHANGELOG.md
├── CLAUDE.md                     ← architecture + conventions
└── Macget.xcodeproj

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Build, test, release

Develop

# Build
xcodebuild -project Macget.xcodeproj -scheme Macget -configuration Debug build

# Run all tests
xcodebuild test -project Macget.xcodeproj -scheme Macget -destination 'platform=macOS'

# Run one test class or method
xcodebuild test -project Macget.xcodeproj -scheme Macget -destination 'platform=macOS' \
    -only-testing:MacgetTests/ChunkPlannerTests

Release a DMG (scripts/release.sh)

Free, no Apple account: run ./scripts/release.sh --no-notarize. It builds an ad-hoc-signed DMG (bundling yt-dlp + ffmpeg), skipping the Developer ID and notarization steps. Sparkle auto-updates still work; users do the one-time Gatekeeper "Open Anyway" from First launch on macOS. This needs only brew install create-dmg and the Sparkle key (step 4 below).

Notarized (frictionless install) requires a paid Apple Developer account — one-time setup:

1. Enroll in the Apple Developer Program ($99/yr) and install a Developer ID Application certificate in your Keychain.
2. Save notarization credentials:

   xcrun notarytool store-credentials "macget-notary" \
       --apple-id "[email protected]" \
       --team-id "YOUR-TEAM-ID" \
       --password "<app-specific password from appleid.apple.com>"
   

3. brew install create-dmg
4. Add the Sparkle SPM dependency in Xcode and run bin/generate_keys. Copy the printed public key into Macget/Resources/Info.plist's SUPublicEDKey. Back up the private key offline.

Per release:

1. Bump Marketing Version + Current Project Version in Xcode's target settings.
2. Add an entry to CHANGELOG.md.
3. Run ./scripts/release.sh from the repo root (builds, notarizes, and writes dist/macget.dmg alongside the versioned dist/Macget-<version>.dmg).
4. Create a GitHub Release and attach dist/macget.dmg as an asset named exactly macget.dmg — the Sparkle appcast enclosure and the Homebrew cask URL both depend on that exact name.
5. Run ./scripts/publish-cask.sh to push the Homebrew cask to the tap.
6. Run Sparkle/bin/generate_appcast site/ and push site/ to GitHub Pages.

The CI workflow at .github/workflows/ci.yml runs build + tests on every push/PR.

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Contributing

Issues and PRs welcome. The Engine/ directory is the high-stakes code — please include unit tests for any change there, and mirror the actor / @Sendable conventions described in CLAUDE.md.

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License

MIT. See LICENSE.