ARCHITECTURE_CONTRACTS

Architecture ownership and dependency contracts

Status: executable in the post-0.3 Unreleased development tree. ARCHITECTURE.md is the repository-wide source of truth; this page explains the checks that enforce its public façades, ownership boundaries, and current-versus-target graph.

State legend

The repository distinguishes three states deliberately:

State	Meaning
Implemented	Present in this tree and protected by tests or an executable gate.
Unreleased 0.4.0 candidate	Implemented or proposed work that has not passed a dedicated 0.4.0 release process.
Later roadmap	Accepted or proposed direction outside the next release; no runtime may depend on it yet.

The shared command specifications, transport-neutral application contracts, shared CommandExecutor, and service-owned genealogy aggregate (#44) are implemented. FastAPI routes and the Electron application remain later-roadmap adapters.

Dependency graph and owners

flowchart TB
    CLI["One-shot CLI adapter"]
    REPL["prompt-toolkit/Rich REPL adapter"]
    Specs["CommandSpec and DispatchKey\n#41 implemented"]
    Contracts["Application DTOs, ports, operations,\nartifacts, and stable errors\n#161 implemented"]
    Terminal["Shared terminal translation\n#42 implemented"]
    Executor["CommandExecutor\n#42 implemented"]
    Handlers["Focused command-family executors\n#42 implemented"]
    Services["Feature services and composition"]
    Aggregate["Genealogy aggregate and\ndeterministic results\n#44 implemented"]
    Domain["Framework-independent domain"]
    Infra["Storage, provider, and file infrastructure"]
    Future["FastAPI and Electron adapters\nlater roadmap"]

    CLI --> Specs
    REPL --> Specs
    Specs --> Contracts
    CLI --> Terminal
    REPL --> Terminal
    Terminal --> Executor
    Executor --> Handlers
    Handlers --> Services
    Executor --> Contracts
    Services --> Domain
    Services --> Infra
    Services --> Aggregate
    Aggregate --> Domain
    Future -. "later adapter dependency" .-> Contracts
    Future -. "later adapter dependency" .-> Executor

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Concern	Authoritative owner
Command grammar, aliases, route identity, and dispatch metadata	ancestryllm.core.commands (#41)
Request/result DTOs, operation inventory, ports, opaque artifact and secret references, stable error envelopes	ancestryllm.application and ancestryllm.domain.errors (#161)
Executable dependency direction, public-façade allowlists, and architecture-state documentation	scripts/check_architecture_contracts.py, this page, and ARCHITECTURE.md (#162)
Shared use-case dispatch and CLI/REPL adapter translation	ancestryllm.application.executor, ancestryllm.terminal, and ancestryllm.execution (#42 implemented)
Identity, provenance, deterministic changes/conflicts, quality findings, and genealogy result semantics	ancestryllm.application.genealogy over ancestryllm.domain.genealogy (#44 implemented)
GEDCOM document model, physical-line parser, validator, deterministic line serializer, graph, identity, quality, service, and synchronization seams	pure document modules behind the declared parser and serialization façades; private compatibility access is limited by PRIVATE_MODULE_GATEWAYS (#163)
RootsMagic immutable source/schema, query orchestration, and GEDCOM mapping/export seams	ancestryllm.rootsmagic.core, .query, and .export; private compatibility access is limited by PRIVATE_MODULE_GATEWAYS
Focused REPL compatibility and migration documentation	docs/REPL_ARCHITECTURE.md (#39)
User, contributor, module-authoring, versioning, and release consistency	final cross-document pass (#179)

Enforced inward dependencies

scripts/check_architecture_contracts.py parses imports without importing the application. It is run by make lint, the ordinary CI workflow, release readiness, and the release workflow.

The checker enforces these rules:

• public application, domain, and core-contract modules may use only the Python standard library and declared inward AncestryLLM contracts;
• application DTOs, ports, domain objects, and core command contracts cannot import Click, prompt-toolkit, Rich, FastAPI, Pydantic, Electron, provider SDKs, configuration, keyring, storage, publication implementations, or host-filesystem Path objects;
• the GEDCOM document model, validator, and deterministic line serializer may depend only on the Python standard library and one another; they cannot import application, infrastructure, adapter, provider, publication, or compatibility-engine code;
• private GEDCOM and RootsMagic compatibility modules may be imported only by the exact importer modules declared in PRIVATE_MODULE_GATEWAYS; owner package membership does not grant blanket access, and application services cannot bypass the public façades;
• an adapter cannot import a sibling adapter or become an application dependency;
• imports from declared public façade modules must use names in their literal __all__ allowlists.

Characterization tests may import private modules to preserve shipped behavior. That test access does not make a private kernel an application or adapter API.

Public façade lifecycle

PUBLIC_FACADE_MODULES is the executable façade inventory. Each listed module has a literal, bound, duplicate-free __all__ allowlist. A new public symbol requires all of the following in the same change:

1. an owner and dependency direction consistent with ARCHITECTURE.md;
2. the explicit __all__ addition;
3. contract or regression tests for its stable behavior;
4. documentation when an adapter or module author may consume it.

Removing a symbol requires the compatibility and versioning process. Renaming an implementation detail does not require a compatibility shim unless that detail was already in a declared façade.

The Unreleased RootsMagic public inventory includes the package façade plus core, query, and export. The GEDCOM inventory exposes parser, graph, identity, quality, serialization, service, and synchronization seams. The parser and serialization façades now re-export a physically separate pure document model, validator, and deterministic line serializer. Remaining centralized private operations remain characterized compatibility kernels, not supported consumer APIs.

Temporary exception lifecycle

An exception is allowed only when it names one exact importer, imported module, and imported symbol tuple, plus a responsible owner, a blocking issue, and a reason. Wildcards, package-wide exemptions, and silent expansion are rejected. A stale exception also fails the gate so completed migration debt is removed.

The #42 shared-executor migration removed all four former CLI/REPL compatibility exceptions and the corresponding inverted imports. The executable exception inventory is empty. Compatibility re-exports remain adapter-local, are covered by focused tests, and do not form a second command registry or service API. Any future exception must satisfy the exact owner, issue, reason, and stale-record checks above.

Validation and review

Run the focused boundary checks with:

PYTHONPATH=src .venv/bin/python scripts/check_architecture_contracts.py
PYTHONPATH=src .venv/bin/pytest tests/modular/test_architecture_contracts.py

The tests prove the repository graph passes, every declared exception is live, valid inward imports are accepted, and representative framework, host-object, private-kernel (including same-owner-package), undeclared-façade, expanded-exception, and stale-exception violations fail with actionable codes.

Before accepting a boundary migration, rerun the core-contract characterization suite, inspect the dependency diff, remove dead exceptions and shims, and complete the canonical make test, make lint, make typecheck, and uninterrupted make security gates.