optional FastAPI service skeleton

docs/service-api-boundary.md

@@ -1,6 +1,6 @@
 # Service API Boundary
 
-Date: 2026-05-05
+Date: 2026-05-06
 
 ## Decision
 
@@ -10,11 +10,34 @@ define separate business behavior; it should expose the same artifact,
 collection, relationship, ingestion, query, workflow, and context operations as
 HTTP resources.
 
-## First Resource Shape
+## Implemented MVP Resource Shape
+
+Implemented in `KONT-WP-0009-T001`:
+
+- `GET /health`
+- `GET /ready`
+- `GET /version`
+- `GET /api/v1/health`
+- `GET /api/v1/ready`
+- `GET /api/v1/version`
+- `GET /openapi.json`
+
+The unversioned health/readiness/version endpoints are operational probes. The
+versioned `/api/v1/*` endpoints establish the MVP API namespace. Future
+domain-resource endpoints should live under `/api/v1`.
+
+The service dependency is optional. Importing `kontextual_engine` and
+`kontextual_engine.api` does not require FastAPI; calling `create_app()` does.
+Install the `service` extra to run the HTTP adapter:
+
+```bash
+python3 -m pip install -e '.[service]'
+```
+
+## Planned Resource Shape
 
 Planned endpoint groups:
 
-- `GET /health`
 - `POST /collections`, `GET /collections`, `GET /collections/{id}`
 - `POST /artifacts`, `GET /artifacts/{id}`, `GET /artifacts`
 - `POST /relationships`, `GET /relationships`
@@ -23,6 +46,21 @@ Planned endpoint groups:
 - `POST /runs`, `GET /runs/{id}`, `GET /runs/{id}/manifest`
 - `POST /context/artifact/{id}`
 
+For the governed asset registry architecture, these planned groups should be
+translated to assets, metadata, relationships, ingestion jobs, retrieval,
+transformations, workflow templates/runs, review queues, and reconstruction
+resources.
+
+## MVP API Versioning Policy
+
+- `/api/v1` is the first stable namespace for implemented service resources.
+- Backward-incompatible changes require a new namespace such as `/api/v2`.
+- Additive response fields are allowed inside a version.
+- Structured diagnostics and error codes are part of the contract and should
+  remain stable inside a version.
+- Unversioned operational probes may remain as aliases for the active API
+  generation, but domain-resource endpoints must be versioned.
+
 ## Rules
 
 - The Python API is canonical until contracts stabilize.
@@ -34,9 +72,11 @@ Planned endpoint groups:
 
 ## Deferred
 
-- Authentication and authorization.
-- Durable database backend.
-- OpenAPI model polishing.
+- Asset, metadata, relationship, audit, and policy endpoints.
+- Ingestion, retrieval, transformation, and workflow endpoints.
+- Actor context, delegation, and authorization middleware.
+- Agent-safe operation catalog.
+- Context package API.
+- Dry-run and review-gate response envelopes for high-impact operations.
 - Streaming run execution.
 - Provider-backed assisted steps.
-

docs/service-api-implementation.md

@@ -0,0 +1,86 @@
+# Service API Implementation Note
+
+Date: 2026-05-06
+
+Status: active implementation note for `KONT-WP-0009`.
+
+## Purpose
+
+This note records the first optional FastAPI service adapter. The service layer
+is intentionally thin: it exposes operational probes and API version metadata
+while leaving domain behavior in the application services.
+
+## Implemented Package Shape
+
+```text
+src/kontextual_engine/
+  api/
+    __init__.py
+    app.py
+```
+
+`kontextual_engine.api.create_app()` builds the FastAPI app when the optional
+`service` extra is installed. Importing the package does not require FastAPI.
+
+## Implemented Endpoints
+
+- `GET /health`
+- `GET /ready`
+- `GET /version`
+- `GET /api/v1/health`
+- `GET /api/v1/ready`
+- `GET /api/v1/version`
+- `GET /openapi.json`
+
+Unversioned endpoints are operational probes. Versioned endpoints establish
+the `/api/v1` namespace for future domain resources.
+
+## Runtime Contract
+
+`ServiceRuntime` owns the adapter runtime state:
+
+- repository reference,
+- API version,
+- service name,
+- startup timestamp,
+- package version discovery,
+- health payload,
+- readiness checks,
+- version payload.
+
+Readiness currently checks that the configured asset registry repository can
+list assets. It does not mutate state.
+
+## Dependency Boundary
+
+The `service` extra now includes FastAPI, Uvicorn, and HTTPX for test-client
+execution:
+
+```text
+kontextual-engine[service]
+```
+
+The current workspace does not have FastAPI installed, so HTTP adapter tests
+are skipped locally until the extra is installed. The pure runtime contract and
+missing-dependency behavior are tested without FastAPI.
+
+## Test Coverage
+
+`tests/test_service_api.py` covers:
+
+- service runtime health/readiness/version without FastAPI installed,
+- `create_app()` missing-dependency behavior when the optional extra is absent,
+- health/readiness/version/OpenAPI endpoint contracts when FastAPI and HTTPX
+  are installed,
+- runtime attachment to FastAPI application state when the service extra is
+  installed.
+
+## Not Yet Implemented
+
+- Asset, metadata, relationship, audit, and policy endpoints.
+- Ingestion, retrieval, transformation, workflow, review, and reconstruction
+  endpoints.
+- Request actor context and delegation middleware.
+- Bounded agent operation catalog.
+- Context package API.
+- Dry-run and review-gate response envelopes.

pyproject.toml

@@ -19,6 +19,7 @@ dev = [
 ]
 service = [
     "fastapi>=0.110",
+    "httpx>=0.27",
     "uvicorn>=0.27",
 ]
 storage = [

src/kontextual_engine/__init__.py

@@ -13,6 +13,7 @@ from .artifacts import (
 )
 from .adapters.memory import InMemoryAssetRegistryRepository
 from .adapters.sqlite import SQLiteAssetRegistryRepository
+from .api import ServiceRuntime, create_app
 from .context import ContextAssembler, ContextItem, ContextPackage
 from .core import (
     Actor,
@@ -235,6 +236,7 @@ __all__ = [
     "RunManifest",
     "RunStatus",
     "Sensitivity",
+    "ServiceRuntime",
     "SourceReference",
     "SourceConnector",
     "SourcePayload",
@@ -271,6 +273,7 @@ __all__ = [
     "WorkflowTemplate",
     "bundle_digest",
     "content_digest",
+    "create_app",
     "default_transformation_registry",
 ]
 

src/kontextual_engine/api/__init__.py

@@ -0,0 +1,5 @@
+"""Optional FastAPI service adapter for Kontextual Engine."""
+
+from .app import ServiceRuntime, create_app
+
+__all__ = ["ServiceRuntime", "create_app"]

src/kontextual_engine/api/app.py

@@ -0,0 +1,123 @@
+"""Versioned FastAPI service skeleton.
+
+The service layer is intentionally thin: route handlers translate HTTP
+requests into service/runtime contracts and must not own domain behavior.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from importlib import metadata
+from typing import Any
+
+from kontextual_engine.adapters.memory import InMemoryAssetRegistryRepository
+from kontextual_engine.core import utc_now
+from kontextual_engine.ports import AssetRegistryRepository
+
+
+API_VERSION = "v1"
+OPENAPI_VERSION = "1.0.0"
+
+
+@dataclass
+class ServiceRuntime:
+    repository: AssetRegistryRepository = field(default_factory=InMemoryAssetRegistryRepository)
+    api_version: str = API_VERSION
+    service_name: str = "kontextual-engine"
+    started_at: str = field(default_factory=lambda: utc_now().isoformat())
+
+    @property
+    def package_version(self) -> str:
+        try:
+            return metadata.version("kontextual-engine")
+        except metadata.PackageNotFoundError:
+            return "0.1.0"
+
+    def health(self) -> dict[str, Any]:
+        return {
+            "status": "ok",
+            "service": self.service_name,
+            "api_version": self.api_version,
+            "package_version": self.package_version,
+            "started_at": self.started_at,
+        }
+
+    def readiness(self) -> dict[str, Any]:
+        checks: dict[str, dict[str, Any]] = {}
+        try:
+            asset_count = len(self.repository.list_assets())
+            checks["asset_registry"] = {
+                "status": "ok",
+                "repository": type(self.repository).__name__,
+                "asset_count": asset_count,
+            }
+        except Exception as exc:
+            checks["asset_registry"] = {
+                "status": "error",
+                "repository": type(self.repository).__name__,
+                "error_type": type(exc).__name__,
+                "message": str(exc),
+            }
+        ready = all(item["status"] == "ok" for item in checks.values())
+        return {
+            "status": "ready" if ready else "not_ready",
+            "ready": ready,
+            "service": self.service_name,
+            "api_version": self.api_version,
+            "checks": checks,
+        }
+
+    def version(self) -> dict[str, Any]:
+        return {
+            "service": self.service_name,
+            "api_version": self.api_version,
+            "package_version": self.package_version,
+            "openapi_version": OPENAPI_VERSION,
+        }
+
+
+def create_app(runtime: ServiceRuntime | None = None):
+    try:
+        from fastapi import FastAPI
+    except ImportError as exc:  # pragma: no cover - exercised when optional extra is absent
+        raise RuntimeError(
+            "FastAPI service dependencies are not installed. Install kontextual-engine[service]."
+        ) from exc
+
+    runtime = runtime or ServiceRuntime()
+    app = FastAPI(
+        title="Kontextual Engine Service API",
+        version=OPENAPI_VERSION,
+        openapi_url="/openapi.json",
+        docs_url="/docs",
+        redoc_url="/redoc",
+    )
+    app.state.kontextual_runtime = runtime
+
+    @app.get("/health", tags=["system"])
+    def health() -> dict[str, Any]:
+        return runtime.health()
+
+    @app.get("/ready", tags=["system"])
+    def ready() -> dict[str, Any]:
+        return runtime.readiness()
+
+    @app.get("/version", tags=["system"])
+    def version() -> dict[str, Any]:
+        return runtime.version()
+
+    prefix = f"/api/{runtime.api_version}"
+
+    @app.get(f"{prefix}/health", tags=["system"])
+    def versioned_health() -> dict[str, Any]:
+        return runtime.health()
+
+    @app.get(f"{prefix}/ready", tags=["system"])
+    def versioned_ready() -> dict[str, Any]:
+        return runtime.readiness()
+
+    @app.get(f"{prefix}/version", tags=["system"])
+    def versioned_version() -> dict[str, Any]:
+        return runtime.version()
+
+    return app

tests/test_service_api.py

@@ -0,0 +1,66 @@
+import pytest
+
+from kontextual_engine import ServiceRuntime, create_app
+from kontextual_engine.adapters.memory import InMemoryAssetRegistryRepository
+
+
+def test_service_runtime_health_readiness_and_version_are_importable_without_fastapi() -> None:
+    runtime = ServiceRuntime(repository=InMemoryAssetRegistryRepository())
+
+    assert runtime.health()["status"] == "ok"
+    assert runtime.readiness()["ready"] is True
+    assert runtime.readiness()["checks"]["asset_registry"]["repository"] == (
+        "InMemoryAssetRegistryRepository"
+    )
+    assert runtime.version()["api_version"] == "v1"
+
+
+def test_create_app_reports_missing_optional_dependency_when_fastapi_is_absent() -> None:
+    try:
+        import fastapi  # noqa: F401
+    except ImportError:
+        with pytest.raises(RuntimeError, match=r"kontextual-engine\[service\]"):
+            create_app()
+    else:
+        pytest.skip("FastAPI is installed; missing-dependency path is not active")
+
+
+@pytest.fixture
+def client():
+    pytest.importorskip("fastapi")
+    pytest.importorskip("httpx")
+    from fastapi.testclient import TestClient
+
+    app = create_app(ServiceRuntime(repository=InMemoryAssetRegistryRepository()))
+    with TestClient(app) as test_client:
+        yield test_client
+
+
+def test_service_health_readiness_version_and_openapi_contracts(client) -> None:
+    health = client.get("/health")
+    ready = client.get("/ready")
+    version = client.get("/version")
+    versioned_health = client.get("/api/v1/health")
+    openapi = client.get("/openapi.json")
+
+    assert health.status_code == 200
+    assert health.json()["status"] == "ok"
+    assert ready.status_code == 200
+    assert ready.json()["ready"] is True
+    assert ready.json()["checks"]["asset_registry"]["status"] == "ok"
+    assert version.status_code == 200
+    assert version.json()["api_version"] == "v1"
+    assert versioned_health.status_code == 200
+    assert versioned_health.json()["api_version"] == "v1"
+    assert openapi.status_code == 200
+    paths = openapi.json()["paths"]
+    assert "/health" in paths
+    assert "/ready" in paths
+    assert "/version" in paths
+    assert "/api/v1/health" in paths
+    assert "/api/v1/ready" in paths
+    assert "/api/v1/version" in paths
+
+
+def test_create_app_attaches_runtime_to_application_state(client) -> None:
+    assert client.app.state.kontextual_runtime.api_version == "v1"

workplans/KONT-WP-0009-service-api-agent-safe-operation.md

@@ -4,13 +4,13 @@ type: workplan
 title: "Service API And Agent-Safe Operation"
 domain: markitect
 repo: kontextual-engine
-status: todo
+status: active
 owner: codex
 topic_slug: markitect
 planning_priority: high
 planning_order: 9
 created: "2026-05-05"
-updated: "2026-05-05"
+updated: "2026-05-06"
 state_hub_workstream_id: "6e672b1a-2e57-489e-8516-cb75611d4354"
 ---
 
@@ -46,11 +46,20 @@ deterministic markdown operations. They must not expose the `mkt` CLI as the
 engine control plane or let agents bypass engine policy, audit, lifecycle, and
 review gates through Markitect APIs.
 
+## Implementation Status
+
+The first optional FastAPI service skeleton is implemented for health,
+readiness, version, and OpenAPI contracts. See
+`docs/service-api-implementation.md`.
+
+Domain-resource endpoints, actor context, agent operations, context packages,
+and dry-run/review-gate response contracts remain open in this workplan.
+
 ## S9.1 - Implement versioned FastAPI service skeleton and health contracts
 
 ```task
 id: KONT-WP-0009-T001
-status: todo
+status: done
 priority: high
 state_hub_task_id: "bdb2380e-4ea1-4b8c-a6c9-fc8da2122813"
 ```
@@ -64,6 +73,15 @@ Acceptance:
 - Service code wraps core contracts rather than becoming the architecture.
 - API versioning policy is documented for MVP.
 
+Implemented:
+
+- `kontextual_engine.api.create_app()` creates an optional FastAPI adapter.
+- `ServiceRuntime` provides health, readiness, and version payloads without
+  requiring FastAPI at import time.
+- Operational probes are exposed at `/health`, `/ready`, and `/version`; MVP
+  versioned aliases are exposed under `/api/v1`.
+- API versioning policy is documented in `docs/service-api-boundary.md`.
+
 ## S9.2 - Expose asset metadata relationship audit and policy APIs
 
 ```task