05. Examples Guide (Spec-Aligned)

This page documents repository examples that follow FACET v2.1.3.

Run any example

facet-fct build --input examples/basic_prompt.facet
facet-fct run --input examples/basic_prompt.facet --runtime-input examples/basic_prompt.input.json --format pretty

1) examples/basic_prompt.facet

Purpose:

• minimal @meta/@context/@vars/@system/@user
• runtime input via @input(type="string")
• Level-0 lenses: trim, uppercase

Key points:

• valid @system uses only content
• canonical output contains metadata, tools, messages

2) examples/rag_pipeline.facet

Purpose:

• deterministic pre-processing of query and corpus
• list/map handling in @vars
• no non-spec @context.documents pattern

RAG in FACET v2.1.3 is represented by variables + messages, while @context remains layout configuration.

3) examples/advanced_features.facet

Purpose:

• typed variables via @var_types
• inline list/map literals
• transformations via pipeline operator |>

4) examples/policy_guard_test.facet

Purpose:

• interface declaration with mandatory effect
• policy allow rules for tool_expose and tool_call
• @test with mocked tool behavior

5) examples/spec/*

The examples/spec directory contains focused conformance snippets for parser/validator/runtime behavior.

Valid syntax checklist for examples

• Message facets (@system/@user/@assistant) use content and optional layout fields/when.
• @system.tools references interfaces as $InterfaceName.
• @context includes only budget and optional defaults map.
• @input(...) appears only as base expression in @vars values (optionally piped).
• String-keyed maps are used only in @meta.

Quick matrix

Notes on legacy syntax

The following patterns are intentionally not used as valid examples:

• @system.role, @system.model, @system.instructions, @system.temperature
• @context.documents
• custom conditional directives not defined by v2.1.3