Scaffold SQLAlchemy models, routers, and Alembic migrations

- app/models/: Printer, Filament, PrintJob, Todo, PricingConfig with full
  SQLAlchemy 2.x mapped columns and relationships
- app/routers/: list + get-by-id endpoints for all five resources
- app/db.py: SQLAlchemy engine + SessionLocal + get_db dependency
- alembic/: env.py reads MYSQL_* env vars; 0001_initial_schema mirrors db.sql
- alembic.ini: script_location configured, URL injected at runtime

Since db.sql already created the tables, stamp the DB before running future
migrations:  alembic stamp head

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

alembic.ini

@@ -0,0 +1,39 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+# URL is set at runtime from env vars in alembic/env.py
+sqlalchemy.url = placeholder
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

alembic/env.py

@@ -0,0 +1,54 @@
+import os
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config, pool
+
+from alembic import context
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+from app.models.base import Base
+import app.models  # noqa: F401 — registers all models with Base.metadata
+
+target_metadata = Base.metadata
+
+
+def get_url() -> str:
+    return (
+        f"mysql+pymysql://{os.environ['MYSQL_USER']}:{os.environ['MYSQL_PASSWORD']}"
+        f"@{os.environ['MYSQL_HOST']}:{os.environ.get('MYSQL_PORT', 3306)}"
+        f"/{os.environ['MYSQL_DATABASE']}"
+    )
+
+
+def run_migrations_offline() -> None:
+    context.configure(
+        url=get_url(),
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    config.set_main_option("sqlalchemy.url", get_url())
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,25 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/0001_initial_schema.py

@@ -0,0 +1,112 @@
+"""initial schema
+
+Revision ID: 0001
+Revises:
+Create Date: 2026-06-18
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import mysql
+
+revision: str = "0001"
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "printers",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("name", sa.String(length=100), nullable=False),
+        sa.Column("model", sa.String(length=100), nullable=True),
+        sa.Column("location", sa.String(length=100), nullable=True),
+        sa.Column(
+            "status",
+            mysql.ENUM("idle", "printing", "error", "offline"),
+            nullable=False,
+            server_default="offline",
+        ),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP")),
+        sa.Column("updated_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP")),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_table(
+        "filaments",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("brand", sa.String(length=100), nullable=True),
+        sa.Column(
+            "material",
+            mysql.ENUM("PLA", "PETG", "ABS", "ASA", "TPU", "Nylon", "PC", "Other"),
+            nullable=False,
+            server_default="PLA",
+        ),
+        sa.Column("color", sa.String(length=100), nullable=True),
+        sa.Column("color_hex", sa.String(length=7), nullable=True),
+        sa.Column("weight_total_g", sa.Numeric(precision=8, scale=2), nullable=False),
+        sa.Column("weight_remaining_g", sa.Numeric(precision=8, scale=2), nullable=False),
+        sa.Column("price_per_kg_eur", sa.Numeric(precision=8, scale=2), nullable=True),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP")),
+        sa.Column("updated_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP")),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_table(
+        "pricing_config",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("name", sa.String(length=100), nullable=False, server_default="default"),
+        sa.Column("electricity_kwh_eur", sa.Numeric(precision=6, scale=4), nullable=False, server_default="0.3000"),
+        sa.Column("printer_watt", sa.Numeric(precision=8, scale=2), nullable=False, server_default="200.00"),
+        sa.Column("hourly_rate_eur", sa.Numeric(precision=8, scale=2), nullable=False, server_default="0.00"),
+        sa.Column("markup_percent", sa.Numeric(precision=5, scale=2), nullable=False, server_default="20.00"),
+        sa.Column("valid_from", sa.Date(), nullable=False, server_default=sa.text("(CURRENT_DATE)")),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP")),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_table(
+        "todos",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("title", sa.String(length=255), nullable=False),
+        sa.Column("done", sa.Boolean(), nullable=False, server_default="0"),
+        sa.Column("printer_id", sa.Integer(), nullable=True),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP")),
+        sa.Column("updated_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP")),
+        sa.ForeignKeyConstraint(["printer_id"], ["printers.id"], name="fk_todo_printer"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_table(
+        "print_jobs",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("printer_id", sa.Integer(), nullable=False),
+        sa.Column("filament_id", sa.Integer(), nullable=True),
+        sa.Column("name", sa.String(length=200), nullable=False),
+        sa.Column("file_name", sa.String(length=255), nullable=True),
+        sa.Column(
+            "status",
+            mysql.ENUM("queued", "printing", "done", "failed", "cancelled"),
+            nullable=False,
+            server_default="queued",
+        ),
+        sa.Column("queue_position", sa.Integer(), nullable=True),
+        sa.Column("started_at", sa.DateTime(), nullable=True),
+        sa.Column("finished_at", sa.DateTime(), nullable=True),
+        sa.Column("duration_minutes", sa.Integer(), nullable=True),
+        sa.Column("filament_used_g", sa.Numeric(precision=8, scale=2), nullable=True),
+        sa.Column("cost_eur", sa.Numeric(precision=8, scale=2), nullable=True),
+        sa.Column("notes", sa.Text(), nullable=True),
+        sa.Column("created_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP")),
+        sa.Column("updated_at", sa.DateTime(), nullable=False, server_default=sa.text("CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP")),
+        sa.ForeignKeyConstraint(["filament_id"], ["filaments.id"], name="fk_job_filament"),
+        sa.ForeignKeyConstraint(["printer_id"], ["printers.id"], name="fk_job_printer"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("print_jobs")
+    op.drop_table("todos")
+    op.drop_table("pricing_config")
+    op.drop_table("filaments")
+    op.drop_table("printers")

app/db.py

@@ -1,22 +1,33 @@
 import os
-import pymysql
+
+from sqlalchemy import create_engine, text
+from sqlalchemy.orm import Session, sessionmaker
 
 
-def _params() -> dict:
+def _db_url() -> str:
-    return {
+    return (
-        "host": os.environ["MYSQL_HOST"],
+        f"mysql+pymysql://{os.environ['MYSQL_USER']}:{os.environ['MYSQL_PASSWORD']}"
-        "port": int(os.environ.get("MYSQL_PORT", 3306)),
+        f"@{os.environ['MYSQL_HOST']}:{os.environ.get('MYSQL_PORT', 3306)}"
-        "user": os.environ["MYSQL_USER"],
+        f"/{os.environ['MYSQL_DATABASE']}"
-        "password": os.environ["MYSQL_PASSWORD"],
+    )
-        "database": os.environ["MYSQL_DATABASE"],
+
-        "connect_timeout": 3,
+
-    }
+engine = create_engine(_db_url(), pool_pre_ping=True)
+SessionLocal = sessionmaker(bind=engine)
+
+
+def get_db():
+    db: Session = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
 
 
 def check_db() -> tuple[bool, str]:
     try:
-        conn = pymysql.connect(**_params())
+        with engine.connect() as conn:
-        conn.close()
+            conn.execute(text("SELECT 1"))
         return True, "ok"
     except Exception as e:
         return False, str(e)

app/main.py

@@ -4,6 +4,7 @@ from contextlib import asynccontextmanager
 from fastapi import FastAPI
 
 from app.db import check_db
+from app.routers import filaments, pricing, print_jobs, printers, todos
 
 logger = logging.getLogger("pops")
 
@@ -20,6 +21,12 @@ async def lifespan(app: FastAPI):
 
 app = FastAPI(title="POPS", lifespan=lifespan)
 
+app.include_router(printers.router)
+app.include_router(filaments.router)
+app.include_router(print_jobs.router)
+app.include_router(todos.router)
+app.include_router(pricing.router)
+
 
 @app.get("/")
 def root():

app/models/__init__.py

@@ -0,0 +1,8 @@
+from app.models.base import Base
+from app.models.filament import Filament
+from app.models.pricing import PricingConfig
+from app.models.print_job import PrintJob
+from app.models.printer import Printer
+from app.models.todo import Todo
+
+__all__ = ["Base", "Printer", "Filament", "PrintJob", "Todo", "PricingConfig"]

app/models/base.py

@@ -0,0 +1,6 @@
+from sqlalchemy.orm import DeclarativeBase
+
+
+class Base(DeclarativeBase):
+    def to_dict(self) -> dict:
+        return {c.name: getattr(self, c.name) for c in self.__table__.columns}

app/models/filament.py

@@ -0,0 +1,38 @@
+import enum
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import DateTime, Enum, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class Material(enum.Enum):
+    PLA = "PLA"
+    PETG = "PETG"
+    ABS = "ABS"
+    ASA = "ASA"
+    TPU = "TPU"
+    Nylon = "Nylon"
+    PC = "PC"
+    Other = "Other"
+
+
+class Filament(Base):
+    __tablename__ = "filaments"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    brand: Mapped[str | None] = mapped_column(String(100))
+    material: Mapped[Material] = mapped_column(Enum(Material), default=Material.PLA)
+    color: Mapped[str | None] = mapped_column(String(100))
+    color_hex: Mapped[str | None] = mapped_column(String(7))
+    weight_total_g: Mapped[Decimal] = mapped_column(Numeric(8, 2))
+    weight_remaining_g: Mapped[Decimal] = mapped_column(Numeric(8, 2))
+    price_per_kg_eur: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    jobs: Mapped[list["PrintJob"]] = relationship(back_populates="filament")

app/models/pricing.py

@@ -0,0 +1,20 @@
+from datetime import date, datetime
+from decimal import Decimal
+
+from sqlalchemy import Date, DateTime, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.models.base import Base
+
+
+class PricingConfig(Base):
+    __tablename__ = "pricing_config"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(100), default="default")
+    electricity_kwh_eur: Mapped[Decimal] = mapped_column(Numeric(6, 4), default=Decimal("0.30"))
+    printer_watt: Mapped[Decimal] = mapped_column(Numeric(8, 2), default=Decimal("200.00"))
+    hourly_rate_eur: Mapped[Decimal] = mapped_column(Numeric(8, 2), default=Decimal("0.00"))
+    markup_percent: Mapped[Decimal] = mapped_column(Numeric(5, 2), default=Decimal("20.00"))
+    valid_from: Mapped[date] = mapped_column(Date, server_default=func.current_date())
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())

app/models/print_job.py

@@ -0,0 +1,41 @@
+import enum
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import DateTime, Enum, ForeignKey, Integer, Numeric, String, Text, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class JobStatus(enum.Enum):
+    queued = "queued"
+    printing = "printing"
+    done = "done"
+    failed = "failed"
+    cancelled = "cancelled"
+
+
+class PrintJob(Base):
+    __tablename__ = "print_jobs"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    printer_id: Mapped[int] = mapped_column(ForeignKey("printers.id"))
+    filament_id: Mapped[int | None] = mapped_column(ForeignKey("filaments.id"))
+    name: Mapped[str] = mapped_column(String(200))
+    file_name: Mapped[str | None] = mapped_column(String(255))
+    status: Mapped[JobStatus] = mapped_column(Enum(JobStatus), default=JobStatus.queued)
+    queue_position: Mapped[int | None] = mapped_column(Integer)
+    started_at: Mapped[datetime | None] = mapped_column(DateTime)
+    finished_at: Mapped[datetime | None] = mapped_column(DateTime)
+    duration_minutes: Mapped[int | None] = mapped_column(Integer)
+    filament_used_g: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    cost_eur: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    notes: Mapped[str | None] = mapped_column(Text)
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    printer: Mapped["Printer"] = relationship(back_populates="jobs")
+    filament: Mapped["Filament | None"] = relationship(back_populates="jobs")

app/models/printer.py

@@ -0,0 +1,33 @@
+import enum
+from datetime import datetime
+
+from sqlalchemy import DateTime, Enum, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class PrinterStatus(enum.Enum):
+    idle = "idle"
+    printing = "printing"
+    error = "error"
+    offline = "offline"
+
+
+class Printer(Base):
+    __tablename__ = "printers"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(100))
+    model: Mapped[str | None] = mapped_column(String(100))
+    location: Mapped[str | None] = mapped_column(String(100))
+    status: Mapped[PrinterStatus] = mapped_column(
+        Enum(PrinterStatus), default=PrinterStatus.offline
+    )
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    jobs: Mapped[list["PrintJob"]] = relationship(back_populates="printer")
+    todos: Mapped[list["Todo"]] = relationship(back_populates="printer")

app/models/todo.py

@@ -0,0 +1,21 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class Todo(Base):
+    __tablename__ = "todos"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    title: Mapped[str] = mapped_column(String(255))
+    done: Mapped[bool] = mapped_column(Boolean, default=False)
+    printer_id: Mapped[int | None] = mapped_column(ForeignKey("printers.id"))
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    printer: Mapped["Printer | None"] = relationship(back_populates="todos")

app/routers/filaments.py

@@ -0,0 +1,21 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db import get_db
+from app.models.filament import Filament
+
+router = APIRouter(prefix="/filaments", tags=["filaments"])
+
+
+@router.get("/")
+def list_filaments(db: Session = Depends(get_db)):
+    return [f.to_dict() for f in db.query(Filament).all()]
+
+
+@router.get("/{filament_id}")
+def get_filament(filament_id: int, db: Session = Depends(get_db)):
+    filament = db.query(Filament).filter(Filament.id == filament_id).first()
+    if not filament:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=404, detail="Filament not found")
+    return filament.to_dict()

app/routers/pricing.py

@@ -0,0 +1,21 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db import get_db
+from app.models.pricing import PricingConfig
+
+router = APIRouter(prefix="/pricing", tags=["pricing"])
+
+
+@router.get("/")
+def list_pricing_configs(db: Session = Depends(get_db)):
+    return [p.to_dict() for p in db.query(PricingConfig).all()]
+
+
+@router.get("/{config_id}")
+def get_pricing_config(config_id: int, db: Session = Depends(get_db)):
+    config = db.query(PricingConfig).filter(PricingConfig.id == config_id).first()
+    if not config:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=404, detail="Pricing config not found")
+    return config.to_dict()

app/routers/print_jobs.py

@@ -0,0 +1,21 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db import get_db
+from app.models.print_job import PrintJob
+
+router = APIRouter(prefix="/jobs", tags=["jobs"])
+
+
+@router.get("/")
+def list_jobs(db: Session = Depends(get_db)):
+    return [j.to_dict() for j in db.query(PrintJob).all()]
+
+
+@router.get("/{job_id}")
+def get_job(job_id: int, db: Session = Depends(get_db)):
+    job = db.query(PrintJob).filter(PrintJob.id == job_id).first()
+    if not job:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=404, detail="Job not found")
+    return job.to_dict()

app/routers/printers.py

@@ -0,0 +1,21 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db import get_db
+from app.models.printer import Printer
+
+router = APIRouter(prefix="/printers", tags=["printers"])
+
+
+@router.get("/")
+def list_printers(db: Session = Depends(get_db)):
+    return [p.to_dict() for p in db.query(Printer).all()]
+
+
+@router.get("/{printer_id}")
+def get_printer(printer_id: int, db: Session = Depends(get_db)):
+    printer = db.query(Printer).filter(Printer.id == printer_id).first()
+    if not printer:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=404, detail="Printer not found")
+    return printer.to_dict()

app/routers/todos.py

@@ -0,0 +1,21 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db import get_db
+from app.models.todo import Todo
+
+router = APIRouter(prefix="/todos", tags=["todos"])
+
+
+@router.get("/")
+def list_todos(db: Session = Depends(get_db)):
+    return [t.to_dict() for t in db.query(Todo).all()]
+
+
+@router.get("/{todo_id}")
+def get_todo(todo_id: int, db: Session = Depends(get_db)):
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        from fastapi import HTTPException
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return todo.to_dict()

requirements.txt

@@ -1,4 +1,6 @@
 fastapi==0.115.6
 uvicorn[standard]==0.34.0
+sqlalchemy==2.0.36
+alembic==1.14.0
 pymysql==1.1.1
 cryptography==44.0.3