Templates and instances

A template owns the input contract and the Markdown renderer for a resource. It is represented by a paired template.jsonc schema and template.md renderer. The schema uses JSON Schema Draft 2020-12.

An instance supplies configured input for one template. It is represented by instance.jsonc and can be selected from a document with $instance or a bare resource locator.

Select a template

Use $template when the binding supplies template-owned input directly:

{
  "agents": {
    "reviewer": {
      "$template": "@atlante/pack/agent",
      "description": "Reviews the implementation.",
      "identity": "You are a careful reviewer.",
      "mission": "Find defects before merge."
    }
  }
}

Use $instance when a reusable configured resource should provide the input:

{
  "agents": {
    "architect": "@atlante/pack/architect"
  }
}

$template and $instance are mutually exclusive. A bare locator is $instance shorthand. Binding metadata is removed before the effective template validates its input.

Compose sections

The first-party agent and skill templates support an ordered sections array. Section variants include markdown, instructions, gotchas, workflow, and invariants. Each section contributes a distinct part of the rendered output, and array order is preserved.

{
  "$template": "@atlante/pack/agent",
  "description": "Implements requested changes.",
  "identity": "You are a senior implementer.",
  "mission": "Write tested, production-ready code.",
  "responsibilities": [
    "Implement the requested change",
    "Keep the project checks passing"
  ],
  "sections": [
    { "invariants": ["Every change ships with tests."] },
    { "instructions": ["Read the relevant source before editing."] }
  ]
}

An invariant is a binding guarantee or approval gate, not a suggestion. Keep invariants minimal, concrete, and observable.

Template composition

A template schema may declare composition slots with { "template": "..." }. Every declared slot must resolve to an available template. Circular composition, missing slots, invalid schemas, and incompatible input fail before rendering.

Rendered child Markdown is preserved as opaque output. It is not interpreted as parent template source.