rulestead

Runtime decisions, made clear.

Typed feature flags, variants, and remote config for Elixir and Phoenix apps — deterministic evaluation, explainable decisions, and fake-backed tests without Postgres on the hot path.

Install {:rulestead, "~> 0.1"} (currently 0.1.x on Hex).

Two version lines: GitHub repo milestones (e.g. v1.0.0 GA, May 2026) track project delivery. Hex packages use 0.1.x semver until a future 1.0 API freeze.

What you get (60 seconds)

Pure Rulestead.evaluate/3 on flag payloads + %Rulestead.Context{}
Keyed snapshot runtime via Rulestead.Runtime.* for Phoenix apps
Ordered rules, sticky bucketing, first-match-wins precedence
Explain API for support and incident response
Installer, migrations, and Rulestead.Fake for tests

Optional sibling package rulestead_admin adds a mounted LiveView operator UI — only when your app needs it.

Install

Host apps need ecto_sql ~> 3.14.

defp deps do
  [
    {:rulestead, "~> 0.1"},
    {:ecto_sql, "~> 3.14"}
  ]
end

mix deps.get
mix rulestead.install
mix ecto.migrate

Phoenix integrators: follow the Phoenix Integration Spine for supervision → Plug → Rulestead.Runtime → lifecycle-honest flag create.

Runtime entrypoints

Keyed lookup (typical Phoenix path):

Rulestead.Runtime.enabled?/3
Rulestead.Runtime.evaluate/3
Rulestead.Runtime.explain/3

Payload-first (tests and tools):

Rulestead.evaluate/3
Rulestead.explain/2

See Evaluation.

Choose your path

You are…	Start here
Evaluating before install	Adoption Lab demo — `docker compose up --build`
Integrating into Phoenix	Getting Started → Installation
Operating flags	Flag Lifecycle → Admin UI
Supporting users	Explainability
Testing	Testing recipes

Monorepo and docs

Full guide index: hexdocs.pm/rulestead

GitHub monorepo (demo app, contributing, maintainer docs): github.com/szTheory/rulestead