LorenEteval_Furious/Furious/Interface/AGENTS.md

Interface guidance

Inherit the root and package guides. This file preserves dependency-light contracts that multiple implementations can satisfy without importing application composition or concrete backends.

• This package defines dependency-light contracts shared across layers. It does not import Qt presentation, controllers, services, repositories, plugins, or concrete backends; a contract may depend on a small model/constant only when that does not trigger application construction or registration.
• Contracts specify observable ownership, lifecycle, mutation, serialization, callback, and failure semantics. Search every representative implementation and contract test before changing one; an implementation may strengthen a guarantee but cannot silently weaken it.
• Interface contracts and the separately versioned plugin API are different compatibility surfaces. Reject unsupported shapes at their owning boundary and update implementations/exports together; do not invent a version gate for every Python interface or remove an established adapter without tracing its callers.
• CoreRuntime is mechanism-neutral: embedded multiprocessing, direct subprocess, or an in-process binding can satisfy it. It owns execution only: zero-argument start, passive liveness, typed terminal events, and bounded idempotent stop/dispose. Preparation, serialization, readiness, and startup transactions belong outside this contract. Bind its event sink once before start; raw exit interpretation occurs once at the concrete runtime boundary. Process/child terminology belongs only to implementations that own one.
• StorageBackend.data() deliberately exposes a live mutable collection for compatibility. Do not reinterpret it as a snapshot or introduce a second authoritative cache. Editor bindings map input to configuration and back; they do not decide runtime, persistence, or host policy.
• ApplicationRunner.ExitCode is a process-boundary protocol. Model encoders may raise, while configuration construction deliberately captures diagnostics; do not impose one blanket exception convention on those different contracts.
• Runtime liveness is observational: querying it must not consume an exit, transfer ownership, or dispatch callbacks. Keep semantic startup errors separate from raw process codes and readiness timeouts.
• Verify cheap/import-independent contracts plus representative runtime, storage, editor, application-exit, encoding, and configuration implementations. Update this guide when a contract intentionally changes, together with all implementers and compatibility tests. Start with tests/test_interface.py and tests/test_runtime_lifecycle.py; include tests/test_public_api.py when imports or exports change.