feat(template): stable fieldId per field — custom_fields keyed by UUID, not label slug

backend/Dockerfile

@@ -1,4 +1,6 @@
 FROM node:20-alpine AS base
+# Prisma migration engine requires OpenSSL
+RUN apk add --no-cache openssl
 WORKDIR /app
 COPY package*.json ./
 RUN npm ci --only=production
@@ -9,9 +11,12 @@ COPY . .
 CMD ["npm", "run", "dev"]
 
 FROM base AS prod
+# Install prisma CLI for migrate deploy at runtime
+RUN npm install prisma --save-dev
 COPY . .
-# Generate Prisma client in the production image
+# Generate Prisma Client
 RUN npx prisma generate
-# Run as non-root user
+# Fix ownership so the node user can write engine cache
+RUN chown -R node:node /app
 USER node
-CMD ["node", "src/index.js"]
+CMD ["/bin/sh", "/app/docker-entrypoint.sh"]

backend/prisma/migrations/20240102000000_add_template_and_custom_fields/migration.sql

@@ -0,0 +1,5 @@
+-- Add template field to experiments (JSON array of field definitions)
+ALTER TABLE "experiments" ADD COLUMN "template" JSONB NOT NULL DEFAULT '[]';
+
+-- Add custom_fields to daily_statuses (stores values for non-builtin fields)
+ALTER TABLE "daily_statuses" ADD COLUMN "custom_fields" JSONB;

backend/prisma/schema.prisma

@@ -1,5 +1,6 @@
 generator client {
   provider      = "prisma-client-js"
+  binaryTargets = ["native", "linux-musl-openssl-3.0.x"]
 }
 
 datasource db {
@@ -11,6 +12,7 @@ model Experiment {
   id         String   @id @default(uuid())
   title      String
   created_at DateTime @default(now())
+  template   Json     @default("[]")
   animals    Animal[]
 
   @@map("experiments")
@@ -35,6 +37,7 @@ model DailyStatus {
   vitals                 String?
   treatment              String?
   notes                  String?
+  custom_fields          Json?
   animal                 Animal   @relation(fields: [animal_id], references: [id], onDelete: Cascade)
 
   @@map("daily_statuses")

backend/src/lib/defaultTemplate.js

@@ -0,0 +1,29 @@
+/**
+ * The default daily-record template applied to every new experiment.
+ *
+ * Builtin fields have FIXED fieldIds so they are stable across all experiments
+ * and can never be confused with user-created fields, even if a user creates a
+ * custom field with the same label.
+ *
+ * `fieldId`     — stable UUID used as the storage key; never changes even if
+ *                 the field is renamed, reordered, or temporarily removed
+ * `key`         — human-readable slug (display only, not used for storage)
+ * `builtin`     — true: value stored in the dedicated column of daily_statuses
+ *                 false: value stored in daily_statuses.custom_fields[fieldId]
+ * `active`      — false: field is hidden (data preserved)
+ */
+const DEFAULT_TEMPLATE = [
+  { fieldId: '00000000-0000-0000-0000-000000000001', key: 'experiment_description', label: 'Experiment Description', type: 'textarea', builtin: true,  active: true },
+  { fieldId: '00000000-0000-0000-0000-000000000002', key: 'vitals',                 label: 'Vitals',                  type: 'text',     builtin: true,  active: true },
+  { fieldId: '00000000-0000-0000-0000-000000000003', key: 'treatment',              label: 'Treatment',               type: 'text',     builtin: true,  active: true },
+  { fieldId: '00000000-0000-0000-0000-000000000004', key: 'notes',                  label: 'Notes',                   type: 'textarea', builtin: true,  active: true },
+];
+
+const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+
+function resolveTemplate(stored) {
+  if (!Array.isArray(stored) || stored.length === 0) return DEFAULT_TEMPLATE;
+  return stored;
+}
+
+module.exports = { DEFAULT_TEMPLATE, resolveTemplate, UUID_RE };

backend/src/routes/dailyStatuses.js

@@ -11,6 +11,7 @@ const statusValidation = [
   body('vitals').optional().isString(),
   body('treatment').optional().isString(),
   body('notes').optional().isString(),
+  body('custom_fields').optional().isObject().withMessage('custom_fields must be an object'),
 ];
 
 const statusUpdateValidation = [
@@ -19,9 +20,10 @@ const statusUpdateValidation = [
   body('vitals').optional().isString(),
   body('treatment').optional().isString(),
   body('notes').optional().isString(),
+  body('custom_fields').optional().isObject().withMessage('custom_fields must be an object'),
 ];
 
-// GET /api/daily-statuses?animalId=<uuid> — list for animal
+// GET /api/daily-statuses?animalId=<uuid>
 router.get(
   '/',
   [query('animalId').optional().matches(/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i).withMessage('animalId must be a valid UUID')],
@@ -35,13 +37,11 @@ router.get(
         include: { animal: { select: { animal_name: true, animal_id_string: true } } },
       });
       res.json(statuses);
-    } catch (err) {
-      next(err);
-    }
+    } catch (err) { next(err); }
   }
 );
 
-// GET /api/daily-statuses/:id — get one
+// GET /api/daily-statuses/:id
 router.get('/:id', async (req, res, next) => {
   try {
     const status = await prisma.dailyStatus.findUnique({
@@ -50,15 +50,13 @@ router.get('/:id', async (req, res, next) => {
     });
     if (!status) return res.status(404).json({ error: 'Daily status not found' });
     res.json(status);
-  } catch (err) {
-    next(err);
-  }
+  } catch (err) { next(err); }
 });
 
-// POST /api/daily-statuses — create
+// POST /api/daily-statuses
 router.post('/', statusValidation, validateRequest, async (req, res, next) => {
   try {
-    const { animal_id, date, experiment_description, vitals, treatment, notes } = req.body;
+    const { animal_id, date, experiment_description, vitals, treatment, notes, custom_fields } = req.body;
     const status = await prisma.dailyStatus.create({
       data: {
         animal_id,
@@ -67,25 +65,17 @@ router.post('/', statusValidation, validateRequest, async (req, res, next) => {
         vitals,
         treatment,
         notes,
+        custom_fields: custom_fields ?? {},
       },
     });
-
     await prisma.auditLog.create({
-      data: {
-        table_name: 'daily_statuses',
-        record_id: status.id,
-        action: 'CREATE',
-        changes: { before: null, after: status },
-      },
+      data: { table_name: 'daily_statuses', record_id: status.id, action: 'CREATE', changes: { before: null, after: status } },
     });
-
     res.status(201).json(status);
-  } catch (err) {
-    next(err);
-  }
+  } catch (err) { next(err); }
 });
 
-// PUT /api/daily-statuses/:id — update
+// PUT /api/daily-statuses/:id
 router.put(
   '/:id',
   auditMiddleware('daily_statuses', prisma.dailyStatus),
@@ -93,26 +83,22 @@ router.put(
   validateRequest,
   async (req, res, next) => {
     try {
-      const { date, experiment_description, vitals, treatment, notes } = req.body;
+      const { date, experiment_description, vitals, treatment, notes, custom_fields } = req.body;
       const data = {};
       if (date !== undefined)                   data.date = new Date(date);
       if (experiment_description !== undefined)  data.experiment_description = experiment_description;
       if (vitals !== undefined)                  data.vitals = vitals;
       if (treatment !== undefined)               data.treatment = treatment;
       if (notes !== undefined)                   data.notes = notes;
+      if (custom_fields !== undefined)           data.custom_fields = custom_fields;
 
-      const status = await prisma.dailyStatus.update({
-        where: { id: req.params.id },
-        data,
-      });
+      const status = await prisma.dailyStatus.update({ where: { id: req.params.id }, data });
       res.json(status);
-    } catch (err) {
-      next(err);
-    }
+    } catch (err) { next(err); }
   }
 );
 
-// DELETE /api/daily-statuses/:id — delete
+// DELETE /api/daily-statuses/:id
 router.delete(
   '/:id',
   auditMiddleware('daily_statuses', prisma.dailyStatus),
@@ -120,9 +106,7 @@ router.delete(
     try {
       await prisma.dailyStatus.delete({ where: { id: req.params.id } });
       res.status(204).send();
-    } catch (err) {
-      next(err);
-    }
+    } catch (err) { next(err); }
   }
 );
 

backend/src/routes/experiments.js

@@ -3,12 +3,77 @@ const { body } = require('express-validator');
 const prisma = require('../lib/prisma');
 const auditMiddleware = require('../middleware/auditMiddleware');
 const { validateRequest } = require('../middleware/errorHandler');
+const { v4: uuidv4 } = require('uuid');
+const { resolveTemplate, DEFAULT_TEMPLATE, UUID_RE } = require('../lib/defaultTemplate');
 
 const experimentValidation = [
   body('title').trim().notEmpty().withMessage('Title is required').isLength({ max: 255 }).withMessage('Title must be ≤255 characters'),
 ];
 
-// GET /api/experiments — list all
+// ── Template validation helpers ────────────────────────────────────────────────
+
+const BUILTIN_FIELD_IDS = new Set(DEFAULT_TEMPLATE.map((f) => f.fieldId));
+const BUILTIN_KEYS      = new Set(DEFAULT_TEMPLATE.map((f) => f.key));
+const VALID_TYPES       = new Set(['text', 'textarea']);
+
+function validateTemplate(template) {
+  if (!Array.isArray(template)) return 'template must be an array';
+  if (template.length > 50) return 'template may have at most 50 fields';
+
+  const seenFieldIds = new Set();
+  const seenKeys     = new Set();
+
+  for (const field of template) {
+    // ── fieldId ────────────────────────────────────────────────────────────────
+    if (!field.fieldId || !UUID_RE.test(field.fieldId))
+      return `each field must have a valid UUID fieldId (got: ${field.fieldId})`;
+    if (seenFieldIds.has(field.fieldId))
+      return `duplicate fieldId "${field.fieldId}"`;
+    seenFieldIds.add(field.fieldId);
+
+    // Builtin fields must keep their original fieldIds
+    if (BUILTIN_KEYS.has(field.key) && !BUILTIN_FIELD_IDS.has(field.fieldId))
+      return `builtin field "${field.key}" must keep its original fieldId`;
+
+    // ── key ────────────────────────────────────────────────────────────────────
+    if (!field.key || typeof field.key !== 'string') return 'each field must have a string key';
+    if (!/^[a-z0-9_]+$/.test(field.key)) return `key "${field.key}" must be lowercase alphanumeric/underscore only`;
+    if (field.key.length > 64) return `key "${field.key}" must be ≤64 characters`;
+    if (seenKeys.has(field.key)) return `duplicate key "${field.key}"`;
+    seenKeys.add(field.key);
+
+    // ── label ──────────────────────────────────────────────────────────────────
+    if (!field.label || typeof field.label !== 'string' || !field.label.trim())
+      return `field "${field.key}" must have a non-empty label`;
+    if (field.label.length > 128) return `label for "${field.key}" must be ≤128 characters`;
+
+    // ── type / active / builtin ────────────────────────────────────────────────
+    if (!VALID_TYPES.has(field.type)) return `field "${field.key}" type must be "text" or "textarea"`;
+    if (typeof field.active !== 'boolean') return `field "${field.key}" must have a boolean active flag`;
+
+    if (BUILTIN_KEYS.has(field.key) && field.builtin !== true)
+      return `field "${field.key}" is a builtin field and cannot be made non-builtin`;
+    if (!BUILTIN_KEYS.has(field.key) && field.builtin !== false)
+      return `custom field "${field.key}" must have builtin: false`;
+  }
+  return null;
+}
+
+/**
+ * Back-fill any missing fieldIds (handles records saved before this feature).
+ * Builtin fields get their canonical IDs; custom fields get fresh UUIDs.
+ */
+function ensureFieldIds(template) {
+  const builtinById = Object.fromEntries(DEFAULT_TEMPLATE.map((f) => [f.key, f.fieldId]));
+  return template.map((f) => ({
+    ...f,
+    fieldId: f.fieldId || (f.builtin ? builtinById[f.key] : uuidv4()),
+  }));
+}
+
+// ── Experiment CRUD ────────────────────────────────────────────────────────────
+
+// GET /api/experiments
 router.get('/', async (req, res, next) => {
   try {
     const experiments = await prisma.experiment.findMany({
@@ -16,12 +81,10 @@ router.get('/', async (req, res, next) => {
       include: { _count: { select: { animals: true } } },
     });
     res.json(experiments);
-  } catch (err) {
-    next(err);
-  }
+  } catch (err) { next(err); }
 });
 
-// GET /api/experiments/:id — get one with animals
+// GET /api/experiments/:id
 router.get('/:id', async (req, res, next) => {
   try {
     const experiment = await prisma.experiment.findUnique({
@@ -29,35 +92,25 @@ router.get('/:id', async (req, res, next) => {
       include: { animals: true },
     });
     if (!experiment) return res.status(404).json({ error: 'Experiment not found' });
+    experiment.template = ensureFieldIds(resolveTemplate(experiment.template));
     res.json(experiment);
-  } catch (err) {
-    next(err);
-  }
+  } catch (err) { next(err); }
 });
 
-// POST /api/experiments — create
+// POST /api/experiments
 router.post('/', experimentValidation, validateRequest, async (req, res, next) => {
   try {
     const { title } = req.body;
     const experiment = await prisma.experiment.create({ data: { title } });
-
-    // Write CREATE audit log
     await prisma.auditLog.create({
-      data: {
-        table_name: 'experiments',
-        record_id: experiment.id,
-        action: 'CREATE',
-        changes: { before: null, after: experiment },
-      },
+      data: { table_name: 'experiments', record_id: experiment.id, action: 'CREATE', changes: { before: null, after: experiment } },
     });
-
+    experiment.template = ensureFieldIds(resolveTemplate(experiment.template));
     res.status(201).json(experiment);
-  } catch (err) {
-    next(err);
-  }
+  } catch (err) { next(err); }
 });
 
-// PUT /api/experiments/:id — update
+// PUT /api/experiments/:id
 router.put(
   '/:id',
   auditMiddleware('experiments', prisma.experiment),
@@ -66,18 +119,14 @@ router.put(
   async (req, res, next) => {
     try {
       const { title } = req.body;
-      const experiment = await prisma.experiment.update({
-        where: { id: req.params.id },
-        data: { title },
-      });
+      const experiment = await prisma.experiment.update({ where: { id: req.params.id }, data: { title } });
+      experiment.template = ensureFieldIds(resolveTemplate(experiment.template));
       res.json(experiment);
-    } catch (err) {
-      next(err);
-    }
+    } catch (err) { next(err); }
   }
 );
 
-// DELETE /api/experiments/:id — delete
+// DELETE /api/experiments/:id
 router.delete(
   '/:id',
   auditMiddleware('experiments', prisma.experiment),
@@ -85,10 +134,51 @@ router.delete(
     try {
       await prisma.experiment.delete({ where: { id: req.params.id } });
       res.status(204).send();
-    } catch (err) {
-      next(err);
-    }
+    } catch (err) { next(err); }
   }
 );
 
+// ── Template endpoints ─────────────────────────────────────────────────────────
+
+// GET /api/experiments/:id/template
+router.get('/:id/template', async (req, res, next) => {
+  try {
+    const experiment = await prisma.experiment.findUnique({
+      where: { id: req.params.id },
+      select: { id: true, template: true },
+    });
+    if (!experiment) return res.status(404).json({ error: 'Experiment not found' });
+    res.json(ensureFieldIds(resolveTemplate(experiment.template)));
+  } catch (err) { next(err); }
+});
+
+// PUT /api/experiments/:id/template
+router.put('/:id/template', async (req, res, next) => {
+  try {
+    const experiment = await prisma.experiment.findUnique({ where: { id: req.params.id } });
+    if (!experiment) return res.status(404).json({ error: 'Experiment not found' });
+
+    const template = req.body;
+    const validationError = validateTemplate(template);
+    if (validationError) return res.status(422).json({ error: validationError });
+
+    const before = ensureFieldIds(resolveTemplate(experiment.template));
+    const updated = await prisma.experiment.update({
+      where: { id: req.params.id },
+      data: { template },
+    });
+
+    await prisma.auditLog.create({
+      data: {
+        table_name: 'experiments',
+        record_id: experiment.id,
+        action: 'UPDATE',
+        changes: { before: { template: before }, after: { template } },
+      },
+    });
+
+    res.json(template);
+  } catch (err) { next(err); }
+});
+
 module.exports = router;

docker-compose.yml

@@ -34,16 +34,16 @@ services:
       NODE_ENV: production
       PORT: 3001
       CORS_ORIGIN: "http://localhost:52867"
-    # Run as non-root
-    user: "node"
+    # Non-root user set in Dockerfile; entrypoint runs migrations then starts server
     entrypoint: ["/bin/sh", "/app/docker-entrypoint.sh"]
     ports:
       - "3001:3001"
     healthcheck:
-      test: ["CMD-SHELL", "wget -qO- http://localhost:3001/health || exit 1"]
-      interval: 15s
+      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1:3001/health || exit 1"]
+      interval: 10s
       timeout: 5s
-      retries: 5
+      retries: 10
+      start_period: 40s
 
   frontend:
     build:

frontend/src/api/client.js

@@ -29,6 +29,8 @@ export const experimentsApi = {
   create: (data) => api.post('/experiments', data).then((r) => r.data),
   update: (id, data) => api.put(`/experiments/${id}`, data).then((r) => r.data),
   delete: (id) => api.delete(`/experiments/${id}`),
+  getTemplate: (id) => api.get(`/experiments/${id}/template`).then((r) => r.data),
+  updateTemplate: (id, template) => api.put(`/experiments/${id}/template`, template).then((r) => r.data),
 };
 
 // ── Animals ───────────────────────────────────────────────────────────────────

frontend/src/components/DailyStatusForm.jsx

@@ -5,42 +5,49 @@ import FormField, { Input, Textarea } from './ui/FormField';
 import Alert from './ui/Alert';
 import { dailyStatusesApi } from '../api/client';
 
-export default function DailyStatusForm({ existing, animalId, onSuccess, onCancel }) {
+const BUILTIN_KEYS = new Set(['experiment_description', 'vitals', 'treatment', 'notes']);
+
+/** Extract the value for a field from a status record.
+ *  Custom fields are keyed by fieldId (stable UUID), not by key (display slug). */
+function getValue(status, field) {
+  if (!status) return '';
+  if (field.builtin) return status[field.key] ?? '';
+  return status.custom_fields?.[field.fieldId] ?? '';
+}
+
+export default function DailyStatusForm({ existing, animalId, template = [], onSuccess, onCancel }) {
   const today = format(new Date(), 'yyyy-MM-dd');
-  const [fields, setFields] = useState({
-    date: existing ? format(new Date(existing.date), 'yyyy-MM-dd') : today,
-    experiment_description: existing?.experiment_description ?? '',
-    vitals: existing?.vitals ?? '',
-    treatment: existing?.treatment ?? '',
-    notes: existing?.notes ?? '',
-  });
+
+  // Active fields from template (date is always first and handled separately)
+  const activeFields = template.filter((f) => f.active);
+
+  function buildInitialValues() {
+    const vals = { date: existing ? format(new Date(existing.date), 'yyyy-MM-dd') : today };
+    for (const f of activeFields) {
+      vals[f.key] = getValue(existing, f);
+    }
+    return vals;
+  }
+
+  const [values, setValues] = useState(buildInitialValues);
   const [errors, setErrors] = useState({});
   const [apiError, setApiError] = useState(null);
   const [loading, setLoading] = useState(false);
 
   useEffect(() => {
-    setFields({
-      date: existing ? format(new Date(existing.date), 'yyyy-MM-dd') : today,
-      experiment_description: existing?.experiment_description ?? '',
-      vitals: existing?.vitals ?? '',
-      treatment: existing?.treatment ?? '',
-      notes: existing?.notes ?? '',
-    });
+    setValues(buildInitialValues());
     setErrors({});
     setApiError(null);
-  }, [existing]);
+  }, [existing, template]);
 
-  const set = (k) => (e) => setFields((f) => ({ ...f, [k]: e.target.value }));
+  const set = (key) => (e) => setValues((v) => ({ ...v, [key]: e.target.value }));
 
   function validate() {
     const e = {};
-    if (!fields.date) {
+    if (!values.date) {
       e.date = 'Date is required';
-    } else if (!/^\d{4}-\d{2}-\d{2}$/.test(fields.date)) {
-      e.date = 'Date must be in YYYY-MM-DD format';
-    } else {
-      const d = new Date(fields.date);
-      if (isNaN(d.getTime())) e.date = 'Invalid date';
+    } else if (!/^\d{4}-\d{2}-\d{2}$/.test(values.date) || isNaN(new Date(values.date).getTime())) {
+      e.date = 'Date must be a valid YYYY-MM-DD date';
     }
     setErrors(e);
     return Object.keys(e).length === 0;
@@ -52,16 +59,31 @@ export default function DailyStatusForm({ existing, animalId, onSuccess, onCance
     setLoading(true);
     setApiError(null);
     try {
-      const payload = {
-        date: fields.date,
-        experiment_description: fields.experiment_description || null,
-        vitals: fields.vitals || null,
-        treatment: fields.treatment || null,
-        notes: fields.notes || null,
-      };
+      // Separate builtin values from custom_fields
+      const builtin = {};
+      const custom = {};
+      for (const f of activeFields) {
+        const val = values[f.key] || null;
+        if (f.builtin) {
+          builtin[f.key] = val;
+        } else {
+          // Always key by fieldId so renaming or recreating a field never
+          // collides with or orphans data from a different field.
+          custom[f.fieldId] = val;
+        }
+      }
+
+      // Preserve custom_fields for fields not in the current active template
+      // (e.g. a field was hidden after this record was created).
+      const existingCustom = existing?.custom_fields ?? {};
+      const mergedCustom = { ...existingCustom, ...custom };
+
+      const payload = { date: values.date, ...builtin, custom_fields: mergedCustom };
+
       const result = existing
         ? await dailyStatusesApi.update(existing.id, payload)
         : await dailyStatusesApi.create({ ...payload, animal_id: animalId });
+
       onSuccess(result);
     } catch (err) {
       setApiError(err);
@@ -73,66 +95,44 @@ export default function DailyStatusForm({ existing, animalId, onSuccess, onCance
   return (
     <form onSubmit={handleSubmit} noValidate className="space-y-4">
       {apiError && (
-        <Alert
-          type="error"
-          message={apiError.message}
-          details={apiError.details}
-          onDismiss={() => setApiError(null)}
+        <Alert type="error" message={apiError.message} details={apiError.details} onDismiss={() => setApiError(null)} />
+      )}
+
+      {/* Date — always present */}
+      <FormField label="Date" name="date" error={errors.date} required>
+        <Input type="date" name="date" value={values.date} onChange={set('date')} required disabled={loading} />
+      </FormField>
+
+      {/* Dynamic fields from template */}
+      {activeFields.map((field) => (
+        <FormField key={field.key} label={field.label} name={field.key}>
+          {field.type === 'textarea' ? (
+            <Textarea
+              name={field.key}
+              value={values[field.key] ?? ''}
+              onChange={set(field.key)}
+              disabled={loading}
+            />
+          ) : (
+            <Input
+              name={field.key}
+              value={values[field.key] ?? ''}
+              onChange={set(field.key)}
+              disabled={loading}
             />
           )}
-      <FormField label="Date" name="date" error={errors.date} required>
-        <Input
-          type="date"
-          name="date"
-          value={fields.date}
-          onChange={set('date')}
-          required
-          disabled={loading}
-        />
-      </FormField>
-      <FormField label="Experiment Description" name="experiment_description">
-        <Textarea
-          name="experiment_description"
-          value={fields.experiment_description}
-          onChange={set('experiment_description')}
-          placeholder="Describe the experimental conditions…"
-          disabled={loading}
-        />
-      </FormField>
-      <FormField label="Vitals" name="vitals">
-        <Input
-          name="vitals"
-          value={fields.vitals}
-          onChange={set('vitals')}
-          placeholder="e.g. HR 72bpm, Temp 37.2°C, Weight 280g"
-          disabled={loading}
-        />
-      </FormField>
-      <FormField label="Treatment" name="treatment">
-        <Input
-          name="treatment"
-          value={fields.treatment}
-          onChange={set('treatment')}
-          placeholder="e.g. Drug X — 10mg/kg oral"
-          disabled={loading}
-        />
-      </FormField>
-      <FormField label="Notes" name="notes">
-        <Textarea
-          name="notes"
-          value={fields.notes}
-          onChange={set('notes')}
-          placeholder="Any additional observations…"
-          disabled={loading}
-        />
         </FormField>
+      ))}
+
+      {activeFields.length === 0 && (
+        <p className="text-sm text-gray-400 italic text-center py-2">
+          No fields configured. Edit the experiment's Record Template to add fields.
+        </p>
+      )}
+
       <div className="flex justify-end gap-3 pt-2">
-        <Button variant="secondary" type="button" onClick={onCancel} disabled={loading}>
-          Cancel
-        </Button>
-        <Button type="submit" loading={loading}>
-          {existing ? 'Save Changes' : 'Log Status'}
-        </Button>
+        <Button variant="secondary" type="button" onClick={onCancel} disabled={loading}>Cancel</Button>
+        <Button type="submit" loading={loading}>{existing ? 'Save Changes' : 'Log Status'}</Button>
       </div>
     </form>
   );

frontend/src/components/TemplateEditor.jsx

@@ -0,0 +1,233 @@
+import React, { useState, useEffect } from 'react';
+import { experimentsApi } from '../api/client';
+import Button from './ui/Button';
+import Alert from './ui/Alert';
+
+// Slugify a label into a valid field key
+function toKey(label) {
+  return label
+    .toLowerCase()
+    .trim()
+    .replace(/[^a-z0-9]+/g, '_')
+    .replace(/^_+|_+$/g, '')
+    .slice(0, 64);
+}
+
+function FieldRow({ field, onChange, onToggle, onRemove, allKeys }) {
+  const [labelDraft, setLabelDraft] = useState(field.label);
+  const [labelError, setLabelError] = useState('');
+
+  useEffect(() => { setLabelDraft(field.label); }, [field.label]);
+
+  function commitLabel() {
+    const trimmed = labelDraft.trim();
+    if (!trimmed) { setLabelError('Label cannot be empty'); return; }
+    if (trimmed.length > 128) { setLabelError('Label must be ≤128 characters'); return; }
+
+    // For custom fields, also ensure the derived key is unique
+    if (!field.builtin) {
+      const newKey = toKey(trimmed);
+      if (!newKey) { setLabelError('Label must contain at least one alphanumeric character'); return; }
+      const duplicate = allKeys.find((k) => k !== field.key && k === newKey);
+      if (duplicate) { setLabelError('A field with this name already exists'); return; }
+    }
+
+    setLabelError('');
+    onChange({ ...field, label: trimmed, key: field.builtin ? field.key : toKey(trimmed) });
+  }
+
+  return (
+    <div className={`flex items-center gap-3 px-4 py-3 rounded-lg border transition-colors ${field.active ? 'bg-white border-gray-200' : 'bg-gray-50 border-gray-100 opacity-60'}`}>
+      {/* Drag handle placeholder (visual only) */}
+      <span className="text-gray-300 cursor-default select-none text-lg leading-none">⠿</span>
+
+      {/* Label input */}
+      <div className="flex-1 min-w-0">
+        <input
+          aria-label={`Field label for ${field.key}`}
+          className={`w-full text-sm rounded border px-2 py-1 focus:outline-none focus:ring-2 focus:ring-blue-500 ${labelError ? 'border-red-400' : 'border-gray-300'} ${!field.active ? 'bg-gray-100' : 'bg-white'}`}
+          value={labelDraft}
+          disabled={!field.active}
+          onChange={(e) => { setLabelDraft(e.target.value); setLabelError(''); }}
+          onBlur={commitLabel}
+          onKeyDown={(e) => { if (e.key === 'Enter') { e.preventDefault(); commitLabel(); } }}
+        />
+        {labelError && <p className="text-xs text-red-500 mt-0.5">{labelError}</p>}
+        <p className="text-xs text-gray-400 mt-0.5 font-mono">
+          key: {field.key}
+          {field.fieldId && (
+            <span className="ml-2 text-gray-300" title={`Stable field ID: ${field.fieldId}`}>
+              · id: {field.fieldId.slice(0, 8)}…
+            </span>
+          )}
+        </p>
+      </div>
+
+      {/* Type badge */}
+      <select
+        aria-label={`Field type for ${field.key}`}
+        className="text-xs border border-gray-200 rounded px-2 py-1 bg-white focus:outline-none focus:ring-1 focus:ring-blue-400 disabled:bg-gray-100"
+        value={field.type}
+        disabled={!field.active}
+        onChange={(e) => onChange({ ...field, type: e.target.value })}
+      >
+        <option value="text">Short text</option>
+        <option value="textarea">Long text</option>
+      </select>
+
+      {/* Toggle active */}
+      <button
+        title={field.active ? 'Hide field' : 'Show field'}
+        aria-label={field.active ? `Hide field ${field.label}` : `Show field ${field.label}`}
+        onClick={() => onToggle(field.key)}
+        className={`text-sm px-2 py-1 rounded border transition-colors ${
+          field.active
+            ? 'border-gray-200 text-gray-500 hover:bg-yellow-50 hover:border-yellow-300 hover:text-yellow-700'
+            : 'border-green-200 text-green-600 hover:bg-green-50'
+        }`}
+      >
+        {field.active ? 'Hide' : 'Show'}
+      </button>
+
+      {/* Remove — only for custom fields */}
+      {!field.builtin && (
+        <button
+          title="Remove field permanently"
+          aria-label={`Remove field ${field.label}`}
+          onClick={() => onRemove(field.key)}
+          className="text-sm px-2 py-1 rounded border border-red-200 text-red-500 hover:bg-red-50 transition-colors"
+        >
+          ✕
+        </button>
+      )}
+    </div>
+  );
+}
+
+export default function TemplateEditor({ experimentId, onClose }) {
+  const [fields, setFields] = useState([]);
+  const [loading, setLoading] = useState(true);
+  const [saving, setSaving] = useState(false);
+  const [error, setError] = useState(null);
+  const [success, setSuccess] = useState(false);
+  const [newLabel, setNewLabel] = useState('');
+  const [newType, setNewType] = useState('text');
+  const [addError, setAddError] = useState('');
+
+  useEffect(() => {
+    experimentsApi.getTemplate(experimentId)
+      .then(setFields)
+      .catch((e) => setError(e.message))
+      .finally(() => setLoading(false));
+  }, [experimentId]);
+
+  function updateField(updated) {
+    setFields((prev) => prev.map((f) => f.key === updated.key ? updated : f));
+  }
+
+  function toggleField(key) {
+    setFields((prev) => prev.map((f) => f.key === key ? { ...f, active: !f.active } : f));
+  }
+
+  function removeField(key) {
+    setFields((prev) => prev.filter((f) => f.key !== key));
+  }
+
+  function addField() {
+    const trimmed = newLabel.trim();
+    if (!trimmed) { setAddError('Field name is required'); return; }
+    const key = toKey(trimmed);
+    if (!key) { setAddError('Name must contain at least one alphanumeric character'); return; }
+    if (fields.some((f) => f.key === key)) { setAddError(`A field with key "${key}" already exists`); return; }
+    setAddError('');
+    const fieldId = crypto.randomUUID();
+    setFields((prev) => [...prev, { fieldId, key, label: trimmed, type: newType, builtin: false, active: true }]);
+    setNewLabel('');
+    setNewType('text');
+  }
+
+  async function save() {
+    setSaving(true);
+    setError(null);
+    try {
+      await experimentsApi.updateTemplate(experimentId, fields);
+      setSuccess(true);
+      setTimeout(() => { setSuccess(false); onClose(fields); }, 800);
+    } catch (e) {
+      setError(e.message);
+    } finally {
+      setSaving(false);
+    }
+  }
+
+  const allKeys = fields.map((f) => f.key);
+
+  return (
+    <div className="space-y-4">
+      {loading && <p className="text-sm text-gray-400">Loading template…</p>}
+      {error && <Alert type="error" message={error} onDismiss={() => setError(null)} />}
+      {success && <Alert type="success" message="Template saved!" />}
+
+      {!loading && (
+        <>
+          {/* Field list */}
+          <div className="space-y-2">
+            {fields.length === 0 && (
+              <p className="text-sm text-gray-400 italic text-center py-4">No fields yet. Add one below.</p>
+            )}
+            {fields.map((field) => (
+              <FieldRow
+                key={field.key}
+                field={field}
+                onChange={updateField}
+                onToggle={toggleField}
+                onRemove={removeField}
+                allKeys={allKeys}
+              />
+            ))}
+          </div>
+
+          {/* Add new field */}
+          <div className="border-t pt-4">
+            <p className="text-xs font-semibold text-gray-500 uppercase tracking-wide mb-2">Add New Field</p>
+            <div className="flex gap-2 items-start">
+              <div className="flex-1">
+                <input
+                  aria-label="New field name"
+                  className={`w-full text-sm rounded border px-3 py-2 focus:outline-none focus:ring-2 focus:ring-blue-500 ${addError ? 'border-red-400' : 'border-gray-300'}`}
+                  placeholder="Field name, e.g. Blood Pressure"
+                  value={newLabel}
+                  onChange={(e) => { setNewLabel(e.target.value); setAddError(''); }}
+                  onKeyDown={(e) => { if (e.key === 'Enter') { e.preventDefault(); addField(); } }}
+                />
+                {addError && <p className="text-xs text-red-500 mt-0.5">{addError}</p>}
+              </div>
+              <select
+                aria-label="New field type"
+                className="text-sm border border-gray-300 rounded px-2 py-2 bg-white focus:outline-none focus:ring-1 focus:ring-blue-400"
+                value={newType}
+                onChange={(e) => setNewType(e.target.value)}
+              >
+                <option value="text">Short text</option>
+                <option value="textarea">Long text</option>
+              </select>
+              <Button size="sm" onClick={addField} type="button">+ Add</Button>
+            </div>
+          </div>
+
+          {/* Info note */}
+          <p className="text-xs text-gray-400">
+            <strong>Hide</strong> removes a builtin field from forms while preserving its data.
+            <strong className="ml-1">✕</strong> permanently removes a custom field (data in existing records is not deleted).
+          </p>
+
+          {/* Actions */}
+          <div className="flex justify-end gap-3 border-t pt-4">
+            <Button variant="secondary" onClick={() => onClose(null)} disabled={saving}>Cancel</Button>
+            <Button onClick={save} loading={saving}>Save Template</Button>
+          </div>
+        </>
+      )}
+    </div>
+  );
+}

frontend/src/pages/AnimalDetail.jsx

@@ -1,6 +1,6 @@
 import React, { useEffect, useState } from 'react';
-import { useParams, useNavigate, Link } from 'react-router-dom';
-import { animalsApi, dailyStatusesApi } from '../api/client';
+import { useParams, useNavigate, Link, useLocation } from 'react-router-dom';
+import { animalsApi, dailyStatusesApi, experimentsApi } from '../api/client';
 import { format } from 'date-fns';
 import Button from '../components/ui/Button';
 import Modal from '../components/ui/Modal';
@@ -9,12 +9,21 @@ import DailyStatusForm from '../components/DailyStatusForm';
 import Alert from '../components/ui/Alert';
 import AuditLogSection from '../components/AuditLogSection';
 
+/** Read the value for a template field from a status record.
+ *  Custom fields are keyed by fieldId, not by the display key. */
+function getFieldValue(status, field) {
+  if (field.builtin) return status[field.key];
+  return status.custom_fields?.[field.fieldId];
+}
+
 export default function AnimalDetail() {
   const { id } = useParams();
   const navigate = useNavigate();
+  const location = useLocation();
 
   const [animal, setAnimal] = useState(null);
   const [statuses, setStatuses] = useState([]);
+  const [template, setTemplate] = useState(location.state?.template ?? []);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState(null);
   const [successMsg, setSuccessMsg] = useState(null);
@@ -34,6 +43,12 @@ export default function AnimalDetail() {
       ]);
       setAnimal(animalData);
       setStatuses(statusData);
+
+      // Fetch template if not passed via navigation state
+      if (!location.state?.template) {
+        const tmpl = await experimentsApi.getTemplate(animalData.experiment_id);
+        setTemplate(tmpl);
+      }
     } catch (err) {
       setError(err.message);
     } finally {
@@ -70,7 +85,7 @@ export default function AnimalDetail() {
     }
   }
 
-  if (loading) return <div className="max-w-5xl mx-auto px-4 py-8 text-gray-400">Loading…</div>;
+  if (loading) return <div className="max-w-5xl mx-auto px-4 py-8 text-gray-400" aria-live="polite" aria-busy="true">Loading…</div>;
   if (error) return (
     <div className="max-w-5xl mx-auto px-4 py-8">
       <Alert type="error" message={error} />
@@ -78,15 +93,15 @@ export default function AnimalDetail() {
     </div>
   );
 
+  const activeFields = template.filter((f) => f.active);
+
   return (
     <div className="max-w-5xl mx-auto px-4 py-8">
       {/* Breadcrumb */}
       <nav className="text-sm text-gray-500 mb-4">
         <Link to="/" className="hover:text-blue-600">Experiments</Link>
         <span className="mx-2">/</span>
-        <Link to={`/experiments/${animal.experiment_id}`} className="hover:text-blue-600">
-          Experiment
-        </Link>
+        <Link to={`/experiments/${animal.experiment_id}`} className="hover:text-blue-600">Experiment</Link>
         <span className="mx-2">/</span>
         <span className="text-gray-900 font-medium">{animal.animal_name}</span>
       </nav>
@@ -124,22 +139,40 @@ export default function AnimalDetail() {
                   <Button size="sm" variant="danger" onClick={() => setDeleteStatus(s)}>Delete</Button>
                 </div>
               </div>
+
+              {activeFields.length > 0 ? (
+                <dl className="grid grid-cols-1 sm:grid-cols-2 gap-x-6 gap-y-2 text-sm">
+                  {activeFields
+                    .map((f) => ({ field: f, value: getFieldValue(s, f) }))
+                    .filter(({ value }) => value)
+                    .map(({ field, value }) => (
+                      <div key={field.key} className={field.type === 'textarea' ? 'sm:col-span-2' : ''}>
+                        <dt className="text-xs font-medium text-gray-500 uppercase tracking-wide">{field.label}</dt>
+                        <dd className="text-gray-800 mt-0.5 whitespace-pre-wrap">{value}</dd>
+                      </div>
+                    ))}
+                </dl>
+              ) : null}
+
+              {/* Fallback: show raw builtin fields if template is empty */}
+              {activeFields.length === 0 && (
                 <dl className="grid grid-cols-1 sm:grid-cols-2 gap-x-6 gap-y-2 text-sm">
                   {[
                     ['Experiment Description', s.experiment_description],
                     ['Vitals', s.vitals],
                     ['Treatment', s.treatment],
                     ['Notes', s.notes],
-                ]
-                  .filter(([, v]) => v)
-                  .map(([label, value]) => (
-                    <div key={label} className="flex flex-col">
+                  ].filter(([, v]) => v).map(([label, value]) => (
+                    <div key={label}>
                       <dt className="text-xs font-medium text-gray-500 uppercase tracking-wide">{label}</dt>
                       <dd className="text-gray-800 mt-0.5 whitespace-pre-wrap">{value}</dd>
                     </div>
                   ))}
                 </dl>
-              {!s.experiment_description && !s.vitals && !s.treatment && !s.notes && (
+              )}
+
+              {activeFields.length > 0 &&
+                activeFields.every((f) => !getFieldValue(s, f)) && (
                   <p className="text-sm text-gray-400 italic">No details recorded for this date.</p>
                 )}
             </div>
@@ -147,16 +180,22 @@ export default function AnimalDetail() {
         </div>
       )}
 
-      <AuditLogSection tableName="daily_statuses" recordId={undefined} />
+      <AuditLogSection tableName="daily_statuses" />
 
       <Modal isOpen={showAddStatus} onClose={() => setShowAddStatus(false)} title="Log Daily Status" size="lg">
-        <DailyStatusForm animalId={id} onSuccess={handleStatusSaved} onCancel={() => setShowAddStatus(false)} />
+        <DailyStatusForm
+          animalId={id}
+          template={template}
+          onSuccess={handleStatusSaved}
+          onCancel={() => setShowAddStatus(false)}
+        />
       </Modal>
 
       <Modal isOpen={!!editStatus} onClose={() => setEditStatus(null)} title="Edit Daily Status" size="lg">
         <DailyStatusForm
           existing={editStatus}
           animalId={id}
+          template={template}
           onSuccess={handleStatusSaved}
           onCancel={() => setEditStatus(null)}
         />

frontend/src/pages/ExperimentDetail.jsx

@@ -5,6 +5,7 @@ import Button from '../components/ui/Button';
 import Modal from '../components/ui/Modal';
 import ConfirmDialog from '../components/ui/ConfirmDialog';
 import AnimalForm from '../components/AnimalForm';
+import TemplateEditor from '../components/TemplateEditor';
 import Alert from '../components/ui/Alert';
 import AuditLogSection from '../components/AuditLogSection';
 
@@ -22,6 +23,7 @@ export default function ExperimentDetail() {
   const [editAnimal, setEditAnimal] = useState(null);
   const [deleteAnimal, setDeleteAnimal] = useState(null);
   const [deleteLoading, setDeleteLoading] = useState(false);
+  const [showTemplate, setShowTemplate] = useState(false);
 
   async function load() {
     setLoading(true);
@@ -69,7 +71,16 @@ export default function ExperimentDetail() {
     }
   }
 
-  if (loading) return <div className="max-w-5xl mx-auto px-4 py-8 text-gray-400">Loading…</div>;
+  function handleTemplateSaved(updatedTemplate) {
+    setShowTemplate(false);
+    if (updatedTemplate) {
+      // Update local experiment state so everything downstream re-renders
+      setExperiment((prev) => ({ ...prev, template: updatedTemplate }));
+      flash('Record template updated.');
+    }
+  }
+
+  if (loading) return <div className="max-w-5xl mx-auto px-4 py-8 text-gray-400" aria-live="polite" aria-busy="true">Loading…</div>;
   if (error) return (
     <div className="max-w-5xl mx-auto px-4 py-8">
       <Alert type="error" message={error} />
@@ -93,12 +104,44 @@ export default function ExperimentDetail() {
             {animals.length} animal{animals.length !== 1 ? 's' : ''} enrolled
           </p>
         </div>
+        <div className="flex gap-2">
+          <Button variant="secondary" onClick={() => setShowTemplate(true)}>
+            <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2}
+                d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2" />
+            </svg>
+            Record Template
+          </Button>
           <Button onClick={() => setShowAddAnimal(true)}>+ Add Animal</Button>
         </div>
+      </div>
 
       {successMsg && <Alert type="success" message={successMsg} />}
       {error && <Alert type="error" message={error} onDismiss={() => setError(null)} />}
 
+      {/* Template summary strip */}
+      {experiment.template && experiment.template.length > 0 && (
+        <div className="mb-5 flex flex-wrap gap-1.5">
+          {experiment.template.map((f) => (
+            <span
+              key={f.key}
+              className={`inline-flex items-center gap-1 px-2 py-0.5 rounded-full text-xs font-medium border ${
+                f.active ? 'bg-blue-50 border-blue-200 text-blue-700' : 'bg-gray-100 border-gray-200 text-gray-400'
+              }`}
+            >
+              {f.active ? null : <span title="hidden">◌</span>}
+              {f.label}
+            </span>
+          ))}
+          <button
+            onClick={() => setShowTemplate(true)}
+            className="text-xs text-gray-400 hover:text-blue-600 underline underline-offset-2 transition-colors"
+          >
+            edit
+          </button>
+        </div>
+      )}
+
       {animals.length === 0 ? (
         <div className="text-center py-16 border-2 border-dashed border-gray-200 rounded-xl">
           <p className="text-gray-400 mb-3">No animals enrolled in this experiment yet.</p>
@@ -110,7 +153,7 @@ export default function ExperimentDetail() {
             <div
               key={animal.id}
               className="bg-white border border-gray-200 rounded-xl p-4 flex items-center justify-between hover:border-blue-300 hover:shadow-sm transition-all cursor-pointer group"
-              onClick={() => navigate(`/animals/${animal.id}`)}
+              onClick={() => navigate(`/animals/${animal.id}`, { state: { template: experiment.template } })}
             >
               <div>
                 <div className="font-semibold text-gray-900 group-hover:text-blue-700 transition-colors">
@@ -129,19 +172,19 @@ export default function ExperimentDetail() {
         </div>
       )}
 
-      <AuditLogSection tableName="animals" recordId={undefined} />
+      <AuditLogSection tableName="animals" />
+
+      {/* Template editor modal */}
+      <Modal isOpen={showTemplate} onClose={() => setShowTemplate(false)} title="Daily Record Template" size="lg">
+        <TemplateEditor experimentId={id} onClose={handleTemplateSaved} />
+      </Modal>
 
       <Modal isOpen={showAddAnimal} onClose={() => setShowAddAnimal(false)} title="Add Animal">
         <AnimalForm experimentId={id} onSuccess={handleAnimalSaved} onCancel={() => setShowAddAnimal(false)} />
       </Modal>
 
       <Modal isOpen={!!editAnimal} onClose={() => setEditAnimal(null)} title="Edit Animal">
-        <AnimalForm
-          existing={editAnimal}
-          experimentId={id}
-          onSuccess={handleAnimalSaved}
-          onCancel={() => setEditAnimal(null)}
-        />
+        <AnimalForm existing={editAnimal} experimentId={id} onSuccess={handleAnimalSaved} onCancel={() => setEditAnimal(null)} />
       </Modal>
 
       <ConfirmDialog