decomposer: generate deliverable files for Implement the task REST API service with FastAPI, including standard CRUD endpoints, HTTP status semantics, request and response models, and structured error handling.; Add a PostgreSQL persistence layer for the task service using SQLAlchemy models, session management, database initialization or migrations, and durable task storage integrated with the existing API contract.; Define and integrate Pydantic request and response schemas for task fields, status values, identifiers, timestamps, and validation errors across the existing FastAPI service and persistence contract.; Add automated pytest coverage for the task API, including CRUD behavior, request and response validation failures, HTTP status semantics, and persistence interactions using isolated test data.; Containerize the FastAPI task service and PostgreSQL persistence service with Docker Compose, including environment-based configuration, health checks, networking, startup dependencies, and persistent database storage.; Create project documentation and operational guidance covering local setup, Docker Compose configuration, environment variables, API endpoints, validation and error responses, testing commands, persistence behavior, and relevant best-practice notes.

app/models.py

@@ -0,0 +1,26 @@
+import enum
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, Enum, String, Text, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from .db import Base
+
+
+class TaskStatus(str, enum.Enum):
+    pending = "pending"
+    in_progress = "in_progress"
+    completed = "completed"
+
+
+class Task(Base):
+    __tablename__ = "tasks"
+
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    title: Mapped[str] = mapped_column(String(200), nullable=False, index=True)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    status: Mapped[TaskStatus] = mapped_column(Enum(TaskStatus, name="task_status"), nullable=False, default=TaskStatus.pending)
+    due_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)