Alchemist

Point it at your media library. Walk away. Come back to a smaller, better-encoded collection.

Alchemist saves space automatically without asking you to babysit shell commands or risk your originals. It is free, open source, self-hosted, and gives you a web UI for setup, monitoring, and day-to-day control. If you want storage back without turning media management into a hobby project, this is the tool.

Why Alchemist?

Running ffmpeg by hand works when you only have a few files and a lot of patience. Tools like Tdarr can scale, but they also ask you to learn a larger system. Alchemist is built for the middle: no plugin stacks, no flow editors, no separate services to install, smart enough to skip files that would not really benefit, shipped as a single binary, genuinely GPLv3 open source instead of source-available, and designed for people who just want it to work.

What It Does

Alchemist scans your library, inspects each file, and decides whether transcoding would actually help. If a file is already efficient, it skips it and tells you why in plain English instead of leaving you to guess.

If supported hardware is available, Alchemist uses it automatically. NVIDIA, Intel, AMD, and Apple Silicon are all detected and used without manual setup, and if there is no GPU available it falls back to CPU encoding on its own.

Your originals stay safe. Alchemist never overwrites anything until the new file passes its quality checks. You can keep both files or let Alchemist replace the original, but nothing is lost until you decide that is what you want.

Everything is visible in the web dashboard. You can see what is running, what was skipped, how much space you have recovered, and pause or cancel work whenever you want.

Features

• Give movies, TV, and home videos different behavior with per-library profiles.
• Convert or remux a single uploaded file from the Convert page using the same pipeline Alchemist uses for library jobs. Experimental.
• Catch corrupt or broken files before they surprise you with Library Doctor.
• See exactly how much storage you have recovered in the savings dashboard.
• Understand every skipped file immediately with plain-English explanations.
• Get a ping when work finishes through Discord, Gotify, Telegram, email, or a webhook.
• Create named API tokens for automation, with read_only and full_access access classes.
• Keep heavy jobs out of the way with a scheduler for off-peak hours.
• Push urgent files to the front with the priority queue.
• Switch the engine between background, balanced, and throughput modes without restarting the app.
• Let hardware acceleration happen automatically on NVIDIA, Intel, AMD, or Apple, with CPU fallback when needed.
• Preserve HDR metadata or tonemap to SDR depending on what you need.
• Add folders once and let watch folders keep monitoring them automatically.
• Shape audio output with stream rules for commentary stripping, language filtering, and default-track retention.
• Surface storage-focused recommendations through Library Intelligence, including remux opportunities and commentary cleanup candidates.

Hardware Support

Alchemist uses hardware acceleration when it can and falls back to CPU encoding automatically when it cannot. You do not need different workflows for different machines.

Vendor	Encoders
NVIDIA	AV1, HEVC, H.264 (NVENC)
Intel	AV1, HEVC, H.264 (QSV)
AMD	HEVC, H.264 (VAAPI/AMF)
Apple	HEVC, H.264 (VideoToolbox)
CPU	AV1 (SVT-AV1), HEVC (x265), H.264 (x264)

CPU fallback is automatic when no GPU is available.

Quick Start

Docker (Recommended)

If you want the fastest path to a running instance, use the published container:

services:
  alchemist:
    image: ghcr.io/bybrooklyn/alchemist:latest
    container_name: alchemist
    ports:
      - "3000:3000"
    volumes:
      - ~/.config/alchemist:/app/config
      - ~/.config/alchemist:/app/data
      - /path/to/media:/media
    environment:
      - ALCHEMIST_CONFIG_PATH=/app/config/config.toml
      - ALCHEMIST_DB_PATH=/app/data/alchemist.db
    restart: unless-stopped

Then open http://localhost:3000 in your browser. First-time setup is only reachable from the local network.

On Linux and macOS, the default host-side config location is ~/.config/alchemist/config.toml. When you use Docker, the recommended bind mount is still ~/.config/alchemist, mapped into /app/config and /app/data inside the container.

If you prefer docker run, this is the trimmed equivalent:

docker run -d --name alchemist -p 3000:3000 -v ~/.config/alchemist:/app/config -v ~/.config/alchemist:/app/data -v /path/to/media:/media -e ALCHEMIST_CONFIG_PATH=/app/config/config.toml -e ALCHEMIST_DB_PATH=/app/data/alchemist.db --restart unless-stopped ghcr.io/bybrooklyn/alchemist:latest

Binary

Download the latest release from GitHub Releases. Prebuilt binaries are published for Linux x86_64, Linux ARM64, Windows x86_64, macOS Intel, and macOS Apple Silicon.

FFmpeg must be installed separately for binary installs:

sudo apt install ffmpeg
sudo dnf install ffmpeg
sudo pacman -S ffmpeg
brew install ffmpeg
winget install Gyan.FFmpeg

Start Alchemist, then open http://localhost:3000:

./alchemist

On Windows, run alchemist.exe instead.

From Source

For macOS and Linux:

git clone https://github.com/bybrooklyn/alchemist.git
cd alchemist
just install
just build
./target/release/alchemist

Alchemist requires Rust 1.85 or later (MSRV). Use rustup update stable to ensure you are on a recent toolchain, and make sure FFmpeg is installed separately.

For Windows local development:

just install-w
just dev
just check

The core contributor path is supported on Windows. Broader release and utility recipes remain Unix-first.

CLI

Alchemist exposes explicit CLI subcommands:

alchemist scan /path/to/media
alchemist run /path/to/media
alchemist plan /path/to/media
alchemist plan /path/to/media --json

• scan enqueues matching work and exits
• run scans, enqueues, and waits for processing to finish
• plan analyzes files and reports what Alchemist would do without enqueuing jobs

First Run

1. Open http://localhost:3000.
2. Complete the setup wizard. It takes about 2 minutes. During first-time setup, the web UI is reachable only from the local network.
3. Add your media folders in Watch Folders.
4. Alchemist scans and starts working automatically.
5. Check the Dashboard to see progress and savings.

Automation + Subpath Notes

• API automation can use bearer tokens created in Settings → API Tokens.
• Read-only tokens are limited to observability and monitoring routes.

Supported Platforms

Platform	Status
Linux x86_64	✅ Supported
Linux ARM64	✅ Supported
Windows x86_64	✅ Supported
macOS Apple Silicon	✅ Supported
macOS Intel	✅ Supported
Docker linux/amd64	✅ Supported
Docker linux/arm64	✅ Supported

License

Licensed under GPLv3. See LICENSE for details.

Contributing

Start with CONTRIBUTING.md for contribution terms, docs/docs/contributing/development.md for local setup, and RELEASING.md for the release process.