Block Resolver: Source Resolution

Every block can be delivered from multiple package sources — Homebrew, the Stackie Cache CDN, npm, pip, web downloads, and more. Source resolution picks the best source for your current machine and preferences automatically.

How It Works

When you run stackie up, each block goes through the resolver before anything is installed. The resolver walks a prioritised list of sources and selects the first one that satisfies three conditions:

The block supports it — the block’s definition lists that source.
Your platform supports it — e.g. brew is available on macOS and Linux, winget only on Windows.
Stackie has it configured — the source driver is loaded and ready.

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Default Source Priority

Stackie ships with sensible per-platform defaults. Sources higher in the list are preferred when a block supports multiple options.

Priority	macOS	Linux	Windows
1	node (Cache)	Cache CDN	node (Cache)
2	system (Cache)	node (Cache)	system (Cache)
3	elixir (Cache)	system (Cache)	elixir (Cache)
4	Cache CDN	elixir (Cache)	Cache CDN
5	Homebrew	web (direct download)	web (direct download)
6	npm	Homebrew	winget
7	pip	npm	scoop
8	gem	pip	npm
9	web (direct download)	gem	pip
10	go (Cache/go install)	go (Cache/go install)	gem
11			go (Cache/go install)

The portable ecosystem sources (node, system, elixir) come first because they use the Stackie Cache CDN — pre-built, versioned binaries delivered without touching your system package manager. The generic supercache source entry covers any remaining CDN-backed packages. Traditional package managers (brew, winget, scoop, chocolatey) and direct web downloads follow as reliable fallbacks. The go source remains available for Go-module packages, but it is not pinned ahead of the main portable runtime sources because it may fall back to local toolchain behavior when no Cache artifact exists.

Customising Your Preferences

You can override non-supercache fallback order from the Stackie dashboard under Settings > Source Preferences. Supercache-backed sources remain pinned first so fresh installs use the Cloud API anonymous-token path immediately.

Prefer Existing Installation

When Prefer existing installation is enabled (Settings > Source Preferences), the resolver first checks whether the package is already installed via any compatible source on your machine. If it finds one, it uses it — skipping the download entirely.

This setting only reuses an existing install from the highest-priority compatible source for the block. A lower-priority system package manager installation must not override a portable Stackie-managed source such as supercache or web.

What Happens When No Source Matches?

If the resolver exhausts every source in the preference list without finding a compatible match, stackie up fails with a descriptive error listing the block’s available sources, your preference order, and the current platform. This usually means the block doesn’t support your operating system yet, or a required source driver isn’t available.