model-language (Ruby)

Ruby bindings for model-language — a typed, safe template language for AI-agent prompts. Runs the exact same engine as the JavaScript/TypeScript package via an embedded WebAssembly module: byte-for-byte identical output, guaranteed by a shared conformance suite.

require "model_language"

engine = ModelLanguage::Engine.new
out = engine.render(
  "Hi {{ user.name | default: 'there' }}!",
  data: { "user" => { "name" => "Vasyl" } }
)
puts out["text"] # => "Hi Vasyl!"

• render(template, data:, schema:, options:) → {"text", "warnings", "resolvedBranches", "directives", "tokenEstimate"}
• validate(template, schema:, options:) → {"diagnostics", "maxTokenEstimate"}
• parse(template) → {"ast", "diagnostics"}

Never raises for template problems — they degrade to empty output plus a warning. Pass options: { "now" => epoch_ms } for datetime filters.