feat: Add extra weight, price tracking, print history, usage analytics

- Extra Weight Field (#14): Track DryPods, custom holders in spool weight
  calculations. New extra_weight field on spool with DB migration.

- Price/Cost Tracking: Compute remaining_value based on remaining weight
  and price. Added column to spool list, inventory value on dashboard.

- Print History: Show print job history on spool detail page with
  collapsible table showing filename, filament used, status, dates.

- Usage Analytics: New dashboard component with time-series chart
  showing daily consumption, period selector (7/30/90 days), and
  material breakdown. New API endpoints for analytics data.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

client/public/locales/en/common.json

@@ -191,11 +191,13 @@
             "weight_to_use": "Weight",
             "used_weight": "Used Weight",
             "remaining_weight": "Remaining Weight",
+            "remaining_value": "Remaining Value",
             "measured_weight": "Measured Weight",
             "used_length": "Used Length",
             "remaining_length": "Remaining Length",
             "initial_weight": "Initial Weight",
             "spool_weight": "Empty Weight",
+            "extra_weight": "Extra Weight",
             "location": "Location",
             "lot_nr": "Lot Nr",
             "first_used": "First Used",
@@ -205,6 +207,8 @@
             "archived": "Archived",
             "adjustment_history": "Adjustment History",
             "show_history": "Show History",
+            "print_history": "Print History",
+            "show_print_history": "Show Print History",
             "adjustment_timestamp": "Date/Time",
             "adjustment_type": "Type",
             "adjustment_type_weight": "Weight",
@@ -220,6 +224,7 @@
             "measured_weight": "How much the filament and spool weigh.",
             "initial_weight": "The initial weight of filament on the spool (net weight). Will use the weight from the filament object if not set.",
             "spool_weight": "The weight of the spool when it is empty. Leave empty to use the value from the filament or the manufacturer.",
+            "extra_weight": "Additional weight to account for when measuring, such as DryPods, custom spool holders, or other accessories.",
             "location": "Where the spool is located if you have multiple locations where you store your spools.",
             "lot_nr": "Manufacturer's lot number. Can be used to ensure a print has consistent color if multiple spools are used.",
             "external_filament": "You have selected a filament from the external database. A filament object (and possibly a manufacturer object) will be created automatically when you create this spool. This can create duplicate filament objects if you have already created a filament object for this filament."
@@ -377,6 +382,20 @@
             "name_required": "Name is required"
         }
     },
+    "print_job": {
+        "fields": {
+            "created": "Created",
+            "filename": "Filename",
+            "filament_used": "Filament Used",
+            "status": "Status",
+            "finished": "Finished"
+        },
+        "status": {
+            "pending": "Pending",
+            "completed": "Completed",
+            "cancelled": "Cancelled"
+        }
+    },
     "home": {
         "home": "Home",
         "welcome": "Welcome to your Spoolman instance!",
@@ -396,7 +415,17 @@
             "total_spools": "Total Spools",
             "total_filaments": "Filament Types",
             "total_vendors": "Vendors",
-            "total_weight": "Total Remaining"
+            "total_weight": "Total Remaining",
+            "total_value": "Inventory Value"
+        },
+        "analytics": {
+            "title": "Usage Analytics",
+            "7_days": "7 Days",
+            "30_days": "30 Days",
+            "90_days": "90 Days",
+            "total_used": "Total used: {{weight}} kg",
+            "used": "Used",
+            "by_material": "Usage by Material"
         }
     },
     "help": {

client/src/pages/home/components/QuickStats.tsx

@@ -1,4 +1,4 @@
-import { HighlightOutlined, InboxOutlined, DatabaseOutlined, UserOutlined } from "@ant-design/icons";
+import { DollarOutlined, HighlightOutlined, InboxOutlined, DatabaseOutlined, UserOutlined } from "@ant-design/icons";
 import { useList, useTranslate } from "@refinedev/core";
 import { Card, Col, Row, Statistic, theme } from "antd";
 import { useMemo } from "react";
@@ -6,12 +6,14 @@ import { Link } from "react-router";
 import { IFilament } from "../../filaments/model";
 import { ISpool } from "../../spools/model";
 import { IVendor } from "../../vendors/model";
+import { useCurrencyFormatter } from "../../../utils/settings";
 
 const { useToken } = theme;
 
 export function QuickStats() {
   const t = useTranslate();
   const { token } = useToken();
+  const currencyFormatter = useCurrencyFormatter();
 
   const { result: filamentsResult, query: filamentsQuery } = useList<IFilament>({
     resource: "filament",
@@ -40,6 +42,12 @@ export function QuickStats() {
     return data.reduce((sum, spool) => sum + (spool.remaining_weight ?? 0), 0);
   }, [spoolsResult?.data]);
 
+  // Calculate total inventory value
+  const totalValue = useMemo(() => {
+    const data = spoolsResult?.data || [];
+    return data.reduce((sum, spool) => sum + (spool.remaining_value ?? 0), 0);
+  }, [spoolsResult?.data]);
+
   const formatWeight = (grams: number) => {
     if (grams >= 1000) {
       return `${(grams / 1000).toFixed(1)} kg`;
@@ -49,7 +57,7 @@ export function QuickStats() {
 
   return (
     <Row gutter={[12, 12]} style={{ marginTop: 16 }}>
-      <Col xs={12} sm={6}>
+      <Col xs={12} md={8} lg={4}>
         <Link to="/spool">
           <Card hoverable size="small">
             <Statistic
@@ -61,7 +69,7 @@ export function QuickStats() {
           </Card>
         </Link>
       </Col>
-      <Col xs={12} sm={6}>
+      <Col xs={12} md={8} lg={4}>
         <Link to="/filament">
           <Card hoverable size="small">
             <Statistic
@@ -73,7 +81,7 @@ export function QuickStats() {
           </Card>
         </Link>
       </Col>
-      <Col xs={12} sm={6}>
+      <Col xs={12} md={8} lg={4}>
         <Link to="/vendor">
           <Card hoverable size="small">
             <Statistic
@@ -85,7 +93,7 @@ export function QuickStats() {
           </Card>
         </Link>
       </Col>
-      <Col xs={12} sm={6}>
+      <Col xs={12} md={12} lg={6}>
         <Card size="small">
           <Statistic
             title={t("home.quick_stats.total_weight")}
@@ -95,6 +103,16 @@ export function QuickStats() {
           />
         </Card>
       </Col>
+      <Col xs={12} md={12} lg={6}>
+        <Card size="small">
+          <Statistic
+            title={t("home.quick_stats.total_value")}
+            value={currencyFormatter.format(totalValue)}
+            loading={spoolsQuery.isLoading}
+            prefix={<DollarOutlined />}
+          />
+        </Card>
+      </Col>
     </Row>
   );
 }

client/src/pages/home/components/UsageAnalytics.tsx

@@ -0,0 +1,123 @@
+import { useTranslate } from "@refinedev/core";
+import { useQuery } from "@tanstack/react-query";
+import { Card, Segmented, Spin, Typography } from "antd";
+import { useState } from "react";
+import { Area, AreaChart, ResponsiveContainer, Tooltip, XAxis, YAxis } from "recharts";
+import { getAPIURL } from "../../../utils/url";
+
+interface UsageDataPoint {
+  date: string;
+  weight_used: number;
+}
+
+interface MaterialUsage {
+  material: string;
+  weight_used: number;
+}
+
+export function UsageAnalytics() {
+  const t = useTranslate();
+  const [days, setDays] = useState<number>(30);
+
+  const { data: usageData, isLoading: usageLoading } = useQuery<UsageDataPoint[]>({
+    queryKey: ["analytics", "usage", days],
+    queryFn: async () => {
+      const res = await fetch(`${getAPIURL()}/analytics/usage?days=${days}`);
+      return res.json();
+    },
+  });
+
+  const { data: materialData, isLoading: materialLoading } = useQuery<MaterialUsage[]>({
+    queryKey: ["analytics", "by-material", days],
+    queryFn: async () => {
+      const res = await fetch(`${getAPIURL()}/analytics/by-material?days=${days}`);
+      return res.json();
+    },
+  });
+
+  // Format date for display
+  const formatDate = (dateStr: string) => {
+    const date = new Date(dateStr);
+    return date.toLocaleDateString(undefined, { month: "short", day: "numeric" });
+  };
+
+  // Calculate total usage
+  const totalUsage = usageData?.reduce((sum, d) => sum + d.weight_used, 0) ?? 0;
+
+  return (
+    <Card
+      title={t("home.analytics.title")}
+      extra={
+        <Segmented
+          value={days}
+          onChange={(v) => setDays(v as number)}
+          options={[
+            { label: t("home.analytics.7_days"), value: 7 },
+            { label: t("home.analytics.30_days"), value: 30 },
+            { label: t("home.analytics.90_days"), value: 90 },
+          ]}
+        />
+      }
+      style={{ marginTop: 16 }}
+    >
+      {usageLoading ? (
+        <div style={{ textAlign: "center", padding: 40 }}>
+          <Spin />
+        </div>
+      ) : (
+        <>
+          <Typography.Text type="secondary">
+            {t("home.analytics.total_used", { weight: (totalUsage / 1000).toFixed(2) })}
+          </Typography.Text>
+          <ResponsiveContainer width="100%" height={200}>
+            <AreaChart data={usageData} margin={{ top: 10, right: 10, left: 0, bottom: 0 }}>
+              <defs>
+                <linearGradient id="colorUsage" x1="0" y1="0" x2="0" y2="1">
+                  <stop offset="5%" stopColor="#1890ff" stopOpacity={0.8} />
+                  <stop offset="95%" stopColor="#1890ff" stopOpacity={0.1} />
+                </linearGradient>
+              </defs>
+              <XAxis
+                dataKey="date"
+                tickFormatter={formatDate}
+                tick={{ fontSize: 11 }}
+                interval="preserveStartEnd"
+              />
+              <YAxis tick={{ fontSize: 11 }} tickFormatter={(v) => `${v}g`} width={50} />
+              <Tooltip
+                formatter={(value) => [`${(value as number).toFixed(1)} g`, t("home.analytics.used")]}
+                labelFormatter={(label) => new Date(label).toLocaleDateString()}
+              />
+              <Area
+                type="monotone"
+                dataKey="weight_used"
+                stroke="#1890ff"
+                fillOpacity={1}
+                fill="url(#colorUsage)"
+              />
+            </AreaChart>
+          </ResponsiveContainer>
+
+          {materialData && materialData.length > 0 && (
+            <>
+              <Typography.Title level={5} style={{ marginTop: 16 }}>
+                {t("home.analytics.by_material")}
+              </Typography.Title>
+              <div style={{ display: "flex", flexWrap: "wrap", gap: 8 }}>
+                {materialData.map((m) => (
+                  <Card size="small" key={m.material} style={{ minWidth: 120 }}>
+                    <Typography.Text strong>{m.material}</Typography.Text>
+                    <br />
+                    <Typography.Text type="secondary">
+                      {m.weight_used >= 1000 ? `${(m.weight_used / 1000).toFixed(2)} kg` : `${m.weight_used.toFixed(0)} g`}
+                    </Typography.Text>
+                  </Card>
+                ))}
+              </div>
+            </>
+          )}
+        </>
+      )}
+    </Card>
+  );
+}

client/src/pages/home/index.tsx

@@ -14,6 +14,7 @@ import { ISpool } from "../spools/model";
 import { AlertCards } from "./components/AlertCards";
 import { MaterialDistributionChart } from "./components/MaterialDistributionChart";
 import { QuickStats } from "./components/QuickStats";
+import { UsageAnalytics } from "./components/UsageAnalytics";
 
 dayjs.extend(utc);
 
@@ -132,6 +133,9 @@ export const Home: React.FC<IResourceComponentsProps> = () => {
       {/* Material distribution chart */}
       <MaterialDistributionChart />
 
+      {/* Usage analytics */}
+      <UsageAnalytics />
+
       {/* Spool list */}
       <Card
         title={t("home.all_spools")}

client/src/pages/spools/create.tsx

@@ -51,6 +51,7 @@ export const SpoolCreate: React.FC<IResourceComponentsProps & CreateOrCloneProps
 
   const initialWeightValue = Form.useWatch("initial_weight", form);
   const spoolWeightValue = Form.useWatch("spool_weight", form);
+  const extraWeightValue = Form.useWatch("extra_weight", form);
 
   if (props.mode === "clone") {
     // Clear out the values that we don't want to clone
@@ -208,10 +209,15 @@ export const SpoolCreate: React.FC<IResourceComponentsProps & CreateOrCloneProps
     return initialWeightValue ?? selectedFilament?.weight ?? 0;
   };
 
+  const getExtraWeight = (): number => {
+    return extraWeightValue ?? 0;
+  };
+
   const getGrossWeight = (): number => {
     const net_weight = getFilamentWeight();
     const spool_weight = getSpoolWeight();
-    return net_weight + spool_weight;
+    const extra_weight = getExtraWeight();
+    return net_weight + spool_weight + extra_weight;
   };
 
   const getMeasuredWeight = (): number => {
@@ -402,6 +408,21 @@ export const SpoolCreate: React.FC<IResourceComponentsProps & CreateOrCloneProps
           <InputNumber addonAfter="g" precision={1} />
         </Form.Item>
 
+        <Form.Item
+          label={t("spool.fields.extra_weight")}
+          help={t("spool.fields_help.extra_weight")}
+          name={["extra_weight"]}
+          rules={[
+            {
+              required: false,
+              type: "number",
+              min: 0,
+            },
+          ]}
+        >
+          <InputNumber addonAfter="g" precision={1} />
+        </Form.Item>
+
         <Form.Item hidden={true} name={["used_weight"]} initialValue={0}>
           <InputNumber value={usedWeight} />
         </Form.Item>

client/src/pages/spools/edit.tsx

@@ -67,6 +67,7 @@ export const SpoolEdit: React.FC<IResourceComponentsProps> = () => {
 
   const initialWeightValue = Form.useWatch("initial_weight", form);
   const spoolWeightValue = Form.useWatch("spool_weight", form);
+  const extraWeightValue = Form.useWatch("extra_weight", form);
 
   // Calculate prev/next IDs for navigation
   const { prevId, nextId } = useMemo(() => {
@@ -189,10 +190,15 @@ export const SpoolEdit: React.FC<IResourceComponentsProps> = () => {
     return initialWeightValue ?? selectedFilament?.weight ?? 0;
   };
 
+  const getExtraWeight = (): number => {
+    return extraWeightValue ?? 0;
+  };
+
   const getGrossWeight = (): number => {
     const net_weight = getFilamentWeight();
     const spool_weight = getSpoolWeight();
-    return net_weight + spool_weight;
+    const extra_weight = getExtraWeight();
+    return net_weight + spool_weight + extra_weight;
   };
 
   const getMeasuredWeight = (): number => {
@@ -394,6 +400,21 @@ export const SpoolEdit: React.FC<IResourceComponentsProps> = () => {
           <InputNumber addonAfter="g" precision={1} />
         </Form.Item>
 
+        <Form.Item
+          label={t("spool.fields.extra_weight")}
+          help={t("spool.fields_help.extra_weight")}
+          name={["extra_weight"]}
+          rules={[
+            {
+              required: false,
+              type: "number",
+              min: 0,
+            },
+          ]}
+        >
+          <InputNumber addonAfter="g" precision={1} />
+        </Form.Item>
+
         <Form.Item hidden={true} name={["used_weight"]} initialValue={0}>
           <InputNumber value={usedWeight} />
         </Form.Item>

client/src/pages/spools/list.tsx

@@ -89,6 +89,7 @@ const allColumns: (keyof ISpoolCollapsed & string)[] = [
   "filament.color_hex",
   "filament.material",
   "price",
+  "remaining_value",
   "used_weight",
   "remaining_weight",
   "used_length",
@@ -101,7 +102,8 @@ const allColumns: (keyof ISpoolCollapsed & string)[] = [
   "comment",
 ];
 const defaultColumns = allColumns.filter(
-  (column_id) => ["registered", "used_length", "remaining_length", "lot_nr", "filament.color_hex"].indexOf(column_id) === -1
+  (column_id) =>
+    ["registered", "used_length", "remaining_length", "lot_nr", "filament.color_hex", "remaining_value"].indexOf(column_id) === -1
 );
 
 export const SpoolList: React.FC<IResourceComponentsProps> = () => {
@@ -462,6 +464,19 @@ export const SpoolList: React.FC<IResourceComponentsProps> = () => {
               return currencyFormatter.format(obj.price);
             },
           }),
+          SortedColumn({
+            ...commonProps,
+            id: "remaining_value",
+            i18ncat: "spool",
+            align: "right",
+            width: 100,
+            render: (_, obj: ISpoolCollapsed) => {
+              if (obj.remaining_value === undefined) {
+                return "";
+              }
+              return currencyFormatter.format(obj.remaining_value);
+            },
+          }),
           NumberColumn({
             ...commonProps,
             id: "used_weight",

client/src/pages/spools/model.tsx

@@ -15,9 +15,11 @@ export interface ISpool {
   price?: number;
   initial_weight?: number;
   spool_weight?: number;
+  extra_weight?: number;
   remaining_weight?: number;
   used_weight: number;
   remaining_length?: number;
+  remaining_value?: number;
   used_length: number;
   location?: string;
   lot_nr?: string;

client/src/pages/spools/show.tsx

@@ -15,7 +15,7 @@ import { useCurrencyFormatter } from "../../utils/settings";
 import { getAPIURL, getBasePath } from "../../utils/url";
 import { IFilament } from "../filaments/model";
 import { setSpoolArchived, useSpoolAdjustModal } from "./functions";
-import { ISpool, ISpoolAdjustment } from "./model";
+import { IPrintJob, ISpool, ISpoolAdjustment } from "./model";
 
 dayjs.extend(utc);
 
@@ -45,6 +45,16 @@ export const SpoolShow: React.FC<IResourceComponentsProps> = () => {
     enabled: !!record?.id,
   });
 
+  // Fetch print job history
+  const { data: printJobsData, isLoading: printJobsLoading } = useQuery({
+    queryKey: ["spool-print-jobs", record?.id],
+    queryFn: async () => {
+      const res = await fetch(`${getAPIURL()}/print-job?spool_id=${record?.id}`);
+      return (await res.json()) as IPrintJob[];
+    },
+    enabled: !!record?.id,
+  });
+
   const spoolPrice = (item?: ISpool) => {
     const price = item?.price ?? item?.filament.price;
     if (price === undefined) {
@@ -288,6 +298,69 @@ export const SpoolShow: React.FC<IResourceComponentsProps> = () => {
           },
         ]}
       />
+      <Title level={4} style={{ marginTop: 24 }}>
+        {t("spool.fields.print_history")}
+      </Title>
+      <Collapse
+        items={[
+          {
+            key: "1",
+            label: t("spool.fields.show_print_history"),
+            children: (
+              <Table<IPrintJob>
+                dataSource={printJobsData}
+                loading={printJobsLoading}
+                rowKey="id"
+                size="small"
+                pagination={{ pageSize: 10 }}
+                columns={[
+                  {
+                    title: t("print_job.fields.created"),
+                    dataIndex: "created",
+                    key: "created",
+                    render: (value: string) => (
+                      <span title={dayjs.utc(value).local().format()}>
+                        {dayjs.utc(value).local().format("YYYY-MM-DD HH:mm:ss")}
+                      </span>
+                    ),
+                  },
+                  {
+                    title: t("print_job.fields.filename"),
+                    dataIndex: "filename",
+                    key: "filename",
+                    ellipsis: true,
+                  },
+                  {
+                    title: t("print_job.fields.filament_used"),
+                    dataIndex: "filament_used_g",
+                    key: "filament_used_g",
+                    render: (value: number) => `${value.toFixed(1)} g`,
+                  },
+                  {
+                    title: t("print_job.fields.status"),
+                    dataIndex: "status",
+                    key: "status",
+                    render: (value: string) => t(`print_job.status.${value}`),
+                  },
+                  {
+                    title: t("print_job.fields.finished"),
+                    dataIndex: "finished",
+                    key: "finished",
+                    render: (value: string | null) =>
+                      value ? (
+                        <span title={dayjs.utc(value).local().format()}>
+                          {dayjs.utc(value).local().format("YYYY-MM-DD HH:mm:ss")}
+                        </span>
+                      ) : (
+                        "-"
+                      ),
+                  },
+                ]}
+              />
+            ),
+          },
+        ]}
+      />
     </Show>
   );
 };

migrations/versions/2025_01_21_0200-f6g7h8i9j0k1_add_spool_extra_weight.py

@@ -0,0 +1,31 @@
+"""Add extra_weight field to spool for DryPods, custom holders, etc.
+
+Revision ID: f6g7h8i9j0k1
+Revises: e5f6g7h8i9j0
+Create Date: 2025-01-21 22:00:00.000000
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "f6g7h8i9j0k1"
+down_revision = "e5f6g7h8i9j0"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "spool",
+        sa.Column(
+            "extra_weight",
+            sa.Float(),
+            nullable=True,
+            comment="Extra weight to account for (DryPods, custom holders, etc.).",
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("spool", "extra_weight")

spoolman/api/v1/models.py

@@ -311,6 +311,12 @@ class Spool(BaseModel):
         description=("Weight of an empty spool (tare weight)."),
         examples=[246],
     )
+    extra_weight: Optional[float] = Field(
+        default=None,
+        ge=0,
+        description=("Extra weight to account for, such as DryPods, custom spool holders, etc."),
+        examples=[50],
+    )
     used_weight: float = Field(
         ge=0,
         description="Consumed weight of filament from the spool in grams.",
@@ -325,6 +331,12 @@ class Spool(BaseModel):
         ),
         examples=[5612.4],
     )
+    remaining_value: Optional[float] = Field(
+        default=None,
+        ge=0,
+        description="Estimated remaining value of filament on the spool based on remaining weight and price.",
+        examples=[12.50],
+    )
     used_length: float = Field(
         ge=0,
         description="Consumed length of filament from the spool in millimeters.",
@@ -389,6 +401,13 @@ class Spool(BaseModel):
             diameter=filament.diameter,
         )
 
+        # Calculate remaining value based on remaining weight and price
+        remaining_value: Optional[float] = None
+        price = item.price if item.price is not None else filament.price
+        initial_weight = item.initial_weight if item.initial_weight is not None else filament.weight
+        if remaining_weight is not None and price is not None and initial_weight is not None and initial_weight > 0:
+            remaining_value = round((remaining_weight / initial_weight) * price, 2)
+
         return Spool(
             id=item.id,
             registered=item.registered,
@@ -398,10 +417,12 @@ class Spool(BaseModel):
             price=item.price,
             initial_weight=item.initial_weight,
             spool_weight=item.spool_weight,
+            extra_weight=item.extra_weight,
             used_weight=item.used_weight,
             used_length=used_length,
             remaining_weight=remaining_weight,
             remaining_length=remaining_length,
+            remaining_value=remaining_value,
             location=item.location,
             lot_nr=item.lot_nr,
             comment=item.comment,

spoolman/api/v1/other.py

@@ -1,13 +1,16 @@
 """Filament related endpoints."""
 
 import logging
-from typing import Annotated
+from datetime import datetime, timedelta
+from typing import Annotated, Optional
 
-from fastapi import APIRouter, Depends
+import sqlalchemy
+from fastapi import APIRouter, Depends, Query
 from pydantic import BaseModel, Field, RootModel
+from sqlalchemy import func
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from spoolman.database import filament, spool
+from spoolman.database import filament, models, spool
 from spoolman.database.database import get_db_session
 
 logger = logging.getLogger(__name__)
@@ -173,3 +176,118 @@ async def rename_location(
     logger.info("Renaming location %s to %s", location, body.name)
     await spool.rename_location(db=db, current_name=location, new_name=body.name)
     return body.name
+
+
+class UsageDataPoint(BaseModel):
+    """A single data point for usage analytics."""
+
+    date: str = Field(description="Date in YYYY-MM-DD format.")
+    weight_used: float = Field(description="Total weight used in grams (positive value).")
+
+
+@router.get(
+    "/analytics/usage",
+    name="Get usage analytics",
+    description="Get filament usage data aggregated by day for the specified period.",
+    response_model=list[UsageDataPoint],
+)
+async def get_usage_analytics(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    days: Annotated[
+        int,
+        Query(description="Number of days to look back.", ge=1, le=365),
+    ] = 30,
+) -> list[UsageDataPoint]:
+    """Get usage analytics aggregated by day."""
+    # Calculate the start date
+    start_date = datetime.utcnow() - timedelta(days=days)
+
+    # Query adjustments grouped by date
+    # Only include negative values (filament used, not added)
+    stmt = (
+        sqlalchemy.select(
+            func.date(models.SpoolAdjustment.timestamp).label("date"),
+            func.sum(
+                sqlalchemy.case(
+                    (models.SpoolAdjustment.value < 0, -models.SpoolAdjustment.value),
+                    else_=0,
+                )
+            ).label("weight_used"),
+        )
+        .where(models.SpoolAdjustment.timestamp >= start_date)
+        .where(models.SpoolAdjustment.adjustment_type == "weight")
+        .group_by(func.date(models.SpoolAdjustment.timestamp))
+        .order_by(func.date(models.SpoolAdjustment.timestamp))
+    )
+
+    result = await db.execute(stmt)
+    rows = result.all()
+
+    # Fill in missing dates with 0
+    data_by_date = {str(row.date): row.weight_used for row in rows}
+    all_dates = []
+    current_date = start_date.date()
+    end_date = datetime.utcnow().date()
+
+    while current_date <= end_date:
+        date_str = current_date.strftime("%Y-%m-%d")
+        all_dates.append(
+            UsageDataPoint(
+                date=date_str,
+                weight_used=data_by_date.get(date_str, 0),
+            )
+        )
+        current_date += timedelta(days=1)
+
+    return all_dates
+
+
+class MaterialUsage(BaseModel):
+    """Usage breakdown by material."""
+
+    material: str = Field(description="Material name.")
+    weight_used: float = Field(description="Total weight used in grams.")
+
+
+@router.get(
+    "/analytics/by-material",
+    name="Get usage by material",
+    description="Get filament usage breakdown by material type.",
+    response_model=list[MaterialUsage],
+)
+async def get_usage_by_material(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    days: Annotated[
+        Optional[int],
+        Query(description="Number of days to look back. If not set, returns all-time usage.", ge=1, le=365),
+    ] = None,
+) -> list[MaterialUsage]:
+    """Get usage breakdown by material."""
+    # Join adjustments with spools and filaments to get material
+    stmt = (
+        sqlalchemy.select(
+            func.coalesce(models.Filament.material, "Unknown").label("material"),
+            func.sum(
+                sqlalchemy.case(
+                    (models.SpoolAdjustment.value < 0, -models.SpoolAdjustment.value),
+                    else_=0,
+                )
+            ).label("weight_used"),
+        )
+        .join(models.Spool, models.SpoolAdjustment.spool_id == models.Spool.id)
+        .join(models.Filament, models.Spool.filament_id == models.Filament.id)
+        .where(models.SpoolAdjustment.adjustment_type == "weight")
+    )
+
+    if days is not None:
+        start_date = datetime.utcnow() - timedelta(days=days)
+        stmt = stmt.where(models.SpoolAdjustment.timestamp >= start_date)
+
+    stmt = stmt.group_by(models.Filament.material).order_by(func.sum(-models.SpoolAdjustment.value).desc())
+
+    result = await db.execute(stmt)
+    rows = result.all()
+
+    return [MaterialUsage(material=row.material or "Unknown", weight_used=row.weight_used) for row in rows]

spoolman/api/v1/spool.py

@@ -51,6 +51,12 @@ class SpoolParameters(BaseModel):
         description="The weight of an empty spool, in grams. (tare weight)",
         examples=[200],
     )
+    extra_weight: Optional[float] = Field(
+        None,
+        ge=0,
+        description="Extra weight to account for, such as DryPods, custom spool holders, etc., in grams.",
+        examples=[50],
+    )
     remaining_weight: Optional[float] = Field(
         None,
         ge=0,
@@ -449,6 +455,7 @@ async def create(  # noqa: ANN201
             price=body.price,
             initial_weight=body.initial_weight,
             spool_weight=body.spool_weight,
+            extra_weight=body.extra_weight,
             remaining_weight=body.remaining_weight,
             used_weight=body.used_weight,
             first_used=body.first_used,

spoolman/database/models.py

@@ -100,6 +100,10 @@ class Spool(Base):
     initial_weight: Mapped[Optional[float]] = mapped_column()
     spool_weight: Mapped[Optional[float]] = mapped_column()
     used_weight: Mapped[float] = mapped_column()
+    extra_weight: Mapped[Optional[float]] = mapped_column(
+        default=None,
+        comment="Extra weight to account for (DryPods, custom holders, etc.).",
+    )
     location: Mapped[Optional[str]] = mapped_column(String(64), comment="Legacy flat location string.")
     location_id: Mapped[Optional[int]] = mapped_column(
         ForeignKey("location.id", ondelete="SET NULL"),

spoolman/database/spool.py

@@ -41,6 +41,7 @@ async def create(
     remaining_weight: Optional[float] = None,
     initial_weight: Optional[float] = None,
     spool_weight: Optional[float] = None,
+    extra_weight: Optional[float] = None,
     used_weight: Optional[float] = None,
     first_used: Optional[datetime] = None,
     last_used: Optional[datetime] = None,
@@ -84,6 +85,7 @@ async def create(
         registered=datetime.utcnow().replace(microsecond=0),
         initial_weight=initial_weight,
         spool_weight=spool_weight,
+        extra_weight=extra_weight,
         used_weight=used_weight,
         price=price,
         first_used=first_used,
@@ -440,7 +442,12 @@ async def measure(
 
     """
     spool_result = await db.execute(
-        sqlalchemy.select(models.Spool.initial_weight, models.Spool.used_weight, models.Spool.spool_weight).where(
+        sqlalchemy.select(
+            models.Spool.initial_weight,
+            models.Spool.used_weight,
+            models.Spool.spool_weight,
+            models.Spool.extra_weight,
+        ).where(
             models.Spool.id == spool_id,
         ),
     )
@@ -452,6 +459,7 @@ async def measure(
 
     initial_weight = spool_info[0]
     spool_weight = spool_info[2]
+    extra_weight = spool_info[3] or 0  # Default to 0 if not set
     if initial_weight is None or initial_weight == 0 or spool_weight is None or spool_weight == 0:
         # Get filament weight and spool_weight
         result = await db.execute(
@@ -473,7 +481,7 @@ async def measure(
     if initial_weight is None or initial_weight == 0:
         raise SpoolMeasureError("Initial weight is not set.")
 
-    initial_gross_weight = initial_weight + spool_weight
+    initial_gross_weight = initial_weight + spool_weight + extra_weight
 
     # if the measurement is greater than the initial weight, set the initial weight to the measurement
     if weight > initial_gross_weight:
@@ -485,9 +493,10 @@ async def measure(
     # Calculate the weight used since last measure
     weight_to_use = current_use - weight
 
-    # If the measured weight is less than the empty weight, use the rest of the spool
+    # If the measured weight is less than the empty weight (+ extra), use the rest of the spool
-    if (initial_gross_weight - weight_to_use) < spool_weight:
+    empty_gross_weight = spool_weight + extra_weight
-        weight_to_use = current_use - spool_weight
+    if (initial_gross_weight - weight_to_use) < empty_gross_weight:
+        weight_to_use = current_use - empty_gross_weight
 
     return await use_weight(db, spool_id, weight_to_use, comment=comment)