The invariant

decorator = contribution to IR, never generated behaviour.

Source: docs/decisions/0001-aot-compilation-is-authoritative.md, docs/decisions/0008-generated-code-is-ordinary-effect.md, docs/decisions/0012-positioning-enterprise-on-ramp.md, AGENTS.md.

What it meansCopy Anchor Link

A decorator or builder call says something about your code. The compiler records that claim as nodes and edges in the IR. Nothing the decorator does at runtime, and nothing the compiler generates, depends on the decorator being executed.

This is what lets effx be an on-ramp rather than a lock-in. The declaration is a familiar surface, and the generated Effect does not depend on it being executed. A team can keep the generated files and stop running the compiler (ADR 0012, Generated code).

@Http.Get("/users/:id")        source syntax
        │  lowers to
        ▼
Annotation { name: "Http.Get", args: ["/users/:id"] }
        │  interpreter returns
        ▼
Contribution { nodes: [Exposure], edges: [ExposedAs], diagnostics: [] }

Contribution is the type an interpreter returns. Its doc comment reads: "What one annotation on one declaration contributes to the IR. Never behaviour." (Source: packages/compiler/src/Extension.ts.)

What it rules outCopy Anchor Link

All invariantsCopy Anchor Link

The table below is the invariant table from AGENTS.md. ADR and spec pages are linked.

How the code keeps itCopy Anchor Link