K9 parser and renderer for Elixir/BEAM.

What this is

k9_ex is the Elixir implementation of the K9 configuration format parser and renderer. K9 is a self-validating component specification format with three graduated security levels: Kennel (data), Yard (contracts), Hunt (execution).

This library parses .k9 files into a typed Elixir AST and round-trips the AST back to K9 surface syntax.

Quick start

Add to mix.exs:

defp deps do
  [
    {:k9_ex, "~> 0.1.0"}
  ]
end

Then:

# Parse a K9 file
{:ok, component} = K9.Parser.parse(File.read!("my-component.k9"))

# Inspect the pedigree
component.pedigree.name    # => "my-component"
component.security.level   # => :kennel

# Round-trip back to K9 syntax
rendered = K9.Renderer.render(component)

Architecture

Module	Purpose
K9.Parser (lib/k9/parser.ex)	Reads .k9 text → typed Component struct. Splits by section (pedigree, security, target, recipes, validation), extracts key-value pairs.
K9.Renderer (lib/k9/renderer.ex)	Reconstructs K9 surface syntax from a Component struct.
K9.Types (lib/k9/types.ex)	Elixir structs: Component, Pedigree, SecurityPolicy, Target, Recipes, Validation.
K9 (lib/k9.ex)	Public API — re-exports parse/1, render/1.
test/k9_test.exs	Round-trip tests, section extraction, error handling.

K9 security levels

Level	What it permits
Kennel (:kennel)	Pure data. Safe to process from any source. Equivalent to Cargo.toml.
Yard (:yard)	Nickel contracts that compute values and validate structure. No shell access.
Hunt (:hunt)	Executable recipes — only permitted when the file carries a valid signature.

K9 ecosystem

k9_ex is one of several language implementations:

• k9-rs — Rust (reference implementation)

• k9-haskell — Haskell

• k9_gleam — Gleam (BEAM + JS)

• pandoc-k9 — Pandoc reader/writer

• tree-sitter-k9 — Editor grammar

License

MPL-2.0 (required for Hex.pm). MPL-2.0 is the preferred intent; MPL-2.0 is required for the Elixir package ecosystem.

See EXPLAINME for implementation evidence and caveats.

Author

Jonathan D.A. Jewell
j.d.a.jewell@open.ac.uk