Typed artifact routing

An executable language plan contains one route for every enabled backend. A route starts at the definition entry artifact, applies selected transformers and passes, and ends at the exact artifact contract required by the selected backend executor.

Typed contract

var syntax = new LanguageArtifactKind<MySyntaxTree>(
    "acme.syntax",
    "com.acme.syntax-tree/v1");

A contract has:

• stable artifact kind ID;
• optional stable public contract identity;
• local CLR type identity for runtime checking.

For independently versioned packages, use an explicit stable contract identity. The CLR-derived identity intentionally excludes assembly version, culture and public-key token, but it still describes a CLR-shaped local contract rather than a cross-ecosystem protocol.

Typed and planning-only untyped contracts do not connect through wildcard semantics. The generic route runtime requires typed executable contracts.

Conversions versus passes

A conversion changes the contract:

source.text<string> -> acme.syntax<MySyntaxTree>
acme.syntax<MySyntaxTree> -> ir.air<MyAir>

A pass preserves the contract and decorates a route stage:

ir.air<MyAir> -> ir.air<MyAir>

The planner finds a minimum-cost conversion route, then inserts applicable passes. Before and After constraints determine pass order. Passes do not need fake artifact names such as air.optimized1 merely to express sequencing.

Backend selection

A backend contribution declares:

• backend ID;
• contribution ID;
• exact input artifact contract;
• executor implementation/factory;
• runtime component traits.

Runtime assembly resolves the exact tuple (contribution, backend, input contract). Reusing a contribution ID for multiple executors is allowed only when backend or input contract differs; ambiguous exact matches fail.

Non-text entry

var document = new LanguageArtifactKind<MyDocument>(
    "acme.document",
    "com.acme.document/v1");

var definition = LanguageDefinitionBuilder.Create("Acme.Language", "1.0.0")
    .WithEntryArtifact(document)
    .UseFeature("acme.core")
    .EnableBackend("interpreter")
    .UseRuntimeProvider("acme.runtime", "1.0.0")
    .Build();

var request = LanguageExecutionRequest.FromArtifact(
    document,
    preparedDocument,
    new BackendId("interpreter"));

The runtime validates the request contract against the plan entry contract before invoking any transformer.