# PromptBuilder `PromptBuilder` is the engine that applies a `PromptRecipe`. It selects a simple branch when one matches the user's input, renders the chosen template, applies provider-oriented formatting, and returns a `PromptResult`. Branch matching is handled by ``PromptBranch.matches()`` in ``src/prompt_recipe_smith/models.py``. The built-in keyword values used by the default recipe are defined in ``src/prompt_recipe_smith/recipes/builtin.py``.