diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c28c8d..2f140d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,46 @@
 # Changelog — FlowDeck
 
-## v5.0.0 (2026-09-06) — Command Palette & Migrations versionnées
+## v5.1.0 (2026-09-06) — Database Avancée : inline DB, templates prédéfinis & validation
+
+> Livre la **v5.3.0** du roadmap : databases inline dans les pages (slash `/database`),
+> galerie de **templates prédéfinis** (CRM, Project tracker, …) et **validation des
+> propriétés** (required / unique / min / max) côté serveur + UI.
+
+### Added — Inline databases (slash `/database`)
+- Commande slash **`/database`** (groupe DATA) dans l'éditeur : ouvre un **sélecteur de
+  templates**, crée une database inline liée à la page et insère un bloc
+  `embed_type:'collection'` rendu par `FlowDeckDB.renderInto`.
+- Le bouton « Database » de la barre *Get Started* ouvre désormais le même sélecteur
+  (au lieu de créer une database vide directement).
+
+### Added — Templates de database prédéfinis
+- **6 templates intégrés** seedés (migration v4) : Project tracker, CRM / Contacts,
+  Task list, Content calendar, Meeting notes, Reading list — avec icône, description et
+  schéma de propriétés.
+- `app/services/db_templates.py` : `materialize_properties()` (schéma → `collection_properties`)
+  et `create_from_template()` (collection + propriétés + vue par défaut).
+- `POST /db/api` et `POST /db/inline/api` acceptent `"template": "<nom>"` et matérialisent
+  les propriétés (titre exclu — c'est le titre de ligne). Colonne `icon` ajoutée à
+  `database_templates` (migration v4).
+- `apply_db_template` (`/workspace/templates/database/{id}/apply`) matérialise les propriétés.
+
+### Added — Validation des propriétés (required / unique / min / max)
+- Nouvelle colonne `collection_properties.validation_json` (migration v4) ; le type/format
+  et les règles de validation sont portés par `validate_property_rule()` dans
+  `property_types.py` (required, unique, min, max, min_length, max_length).
+- **Serveur** : `create_page_api` et `update_page_api` (`/db/{c}/pages/api`,
+  `/db/pages/{id}/api`) valident les valeurs avant écriture → 400 + message clair. La règle
+  `unique` exclut la page en cours d'édition. Les valeurs sont résolues par id **ou** par nom.
+- **API propriétés** : `POST/PUT /db/{c}/properties/api` acceptent `validation` (persisté).
+- **UI** (`_database_table_scripts.html`) : la modale « Add property » expose Required,
+  Unique, Min, Max ; en cas de 400 à l'édition d'une cellule, la cellule est marquée en rouge
+  et un toast affiche le message (valeur restaurée).
+
+### Tests
+- **271 tests** (+9 dans `tests/test_db_advanced.py`) : templates seedés, création de
+  collection/inline depuis template (propriétés matérialisées), apply template, validation
+  required/unique/min-max (create + update, exclusion de la ligne courante), persistance de
+  la config de validation, payload collection.
 
 > Livre deux chantiers du roadmap v5 : la **migration au système de schéma versionné**
 > (v5.2.0, priorité n°1 — débloque tout le reste) et la **Command Palette + recherche
diff --git a/ROADMAP.md b/ROADMAP.md
index 767b373..affb90e 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -466,10 +466,12 @@ app/
 - [ ] Tests des adapters forge (mock HTTP)
 - [ ] Tests multi-user (permissions croisées)
 
-### v5.3.0 — Database Avancée ⬜ (partiel)
-- [ ] **Inline databases dans n'importe quelle page** *(PARTIEL : API `POST /db/inline/api` existe depuis v4.1.0 ; manque l'insertion via slash command `/database` + bloc rendu dans l'éditeur)*
-- [ ] **Templates de database prédéfinis** (CRM, Project tracker…) — galerie au clic « New database » *(templates de pages existent, pas de galerie DB)*
-- [ ] **Validation des propriétés** (required, unique, min/max) — côté serveur + messages UI
+### v5.3.0 — Database Avancée ✅ (2026-09-06)
+> **Objectif** : databases inline + templates prédéfinis + validation propriétés. **COMPLETED**.
+
+- [x] **Inline databases dans n'importe quelle page** — slash command `/database` (groupe DATA) → sélecteur de templates → bloc `embed_type:'collection'` rendu par `FlowDeckDB`
+- [x] **Templates de database prédéfinis** — 6 templates seedés (CRM, Project tracker, Task list, Content calendar, Meeting notes, Reading list) + galerie au clic « Database » (Get Started) et `/database` ; `POST /db/api` & `/db/inline/api` acceptent `template` et matérialisent les propriétés
+- [x] **Validation des propriétés** (required, unique, min/max) — côté serveur (`validate_property_rule`, 400 + messages) + UI (modale propriété + erreurs de cellule)
 
 ### v5.4.0 — Expérience éditeur (nouveautés, parité Notion)
 - [ ] **Backlinks** — section « Lié depuis… » en bas de page (scan des liens internes)
@@ -601,7 +603,7 @@ app/
 
 1. ~~**v5.2.0 → Migrations versionnées**~~ ✅ livré (`schema_version` + `app/migrations.py`)
 2. ~~**v5.0.0 → Command palette + FTS5**~~ ✅ livré (palette Ctrl+K + `GET /api/search`)
-3. **v5.3.0 → Inline databases dans pages** — API serveur prête, uniquement travail éditeur
+3. ~~**v5.3.0 → Inline databases + templates + validation**~~ ✅ livré (slash `/database`, 6 templates, validation propriétés)
 4. **v5.13.0 → Realtime (WS + présence)** — chantier de parité Notion n°1, socle aussi pour v5.14 (synced blocks)
 5. **v5.10.0 → Interactions de bloc** (drag&drop, undo/redo, duplicate) — gros impact UX, effort modéré
 ---
@@ -622,4 +624,4 @@ Quality      DB views,      Agent IA     Palette →       Éditeur bloc      Re
                                           DB avancée,     Wiki-links,
                                           Calendrier, AI  Templates & lock
 
-*Dernière mise à jour: 2026-09-06 — v5.0.0 Command Palette + FTS5 et v5.2.0 Migrations versionnées (schema_version) + indexes livrés (267 tests) ; reste v5.3 → v6.0*
+*Dernière mise à jour: 2026-09-06 — v5.0.0 (palette+FTS5) et v5.2.0 (migrations versionnées) livrés ; v5.3.0 Database Avancée livré (inline `/database`, 6 templates prédéfinis, validation propriétés, 280 tests) ; reste v5.4 → v6.0*
diff --git a/VERSION b/VERSION
index 28cbf7c..acf69b4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.0.0
\ No newline at end of file
+5.1.0
\ No newline at end of file
diff --git a/app/main.py b/app/main.py
index 0cf3be2..c07f19e 100644
--- a/app/main.py
+++ b/app/main.py
@@ -60,7 +60,7 @@ async def lifespan(_app: FastAPI):
 
 app = FastAPI(
     title="FlowDeck",
-    version="5.0.0",
+    version="5.1.0",
     docs_url="/docs" if settings.log_level == "DEBUG" else None,
     redoc_url=None,
     lifespan=lifespan,
diff --git a/app/migrations.py b/app/migrations.py
index 19aca77..956c6e7 100644
--- a/app/migrations.py
+++ b/app/migrations.py
@@ -169,4 +169,27 @@ def _migration_fts5(conn: sqlite3.Connection) -> None:
         SELECT id, COALESCE(title, ''), COALESCE(content, '') FROM pages
         WHERE deleted_at IS NULL
         """
-    )
\ No newline at end of file
+    )
+
+
+@register(4, "database templates (icon) + property validation")
+def _migration_db_templates_validation(conn: sqlite3.Connection) -> None:
+    """v5.3.0: database templates get an icon, properties a validation config,
+    and the built-in database templates are seeded (idempotently)."""
+    _cols = {r[1] for r in conn.execute("PRAGMA table_info(database_templates)").fetchall()}
+    if "icon" not in _cols:
+        conn.execute("ALTER TABLE database_templates ADD COLUMN icon TEXT NOT NULL DEFAULT '📋'")
+
+    _pcols = {r[1] for r in conn.execute("PRAGMA table_info(collection_properties)").fetchall()}
+    if "validation_json" not in _pcols:
+        conn.execute("ALTER TABLE collection_properties ADD COLUMN validation_json TEXT NOT NULL DEFAULT '{}'")
+
+    # Seed built-in templates (idempotent: only missing names are inserted).
+    from app.services.db_templates import SEED_TEMPLATES
+    for tpl in SEED_TEMPLATES:
+        conn.execute(
+            """INSERT OR IGNORE INTO database_templates (name, icon, description, schema_json)
+               VALUES (?, ?, ?, ?)""",
+            (tpl["name"], tpl.get("icon", "📋"), tpl.get("description", ""),
+             __import__("json").dumps(tpl.get("schema", []))),
+        )
\ No newline at end of file
diff --git a/app/routers/collections.py b/app/routers/collections.py
index 3273c95..b659ba4 100644
--- a/app/routers/collections.py
+++ b/app/routers/collections.py
@@ -10,11 +10,73 @@ from fastapi.responses import HTMLResponse
 
 from app.db import get_conn
 from app.auth.session import SessionManager
+from app.services.property_types import validate_property_rule
+from app.services.db_templates import materialize_properties
 
 logger = logging.getLogger(__name__)
 router = APIRouter(tags=["collections"], prefix="/db")
 
 
+def _apply_template(conn, template_name: str) -> dict | None:
+    """Resolve a database template by name (from the seeded/built-in set)."""
+    if not template_name:
+        return None
+    row = conn.execute(
+        "SELECT id, name, icon, description, schema_json FROM database_templates WHERE name=?",
+        (template_name,),
+    ).fetchone()
+    if row:
+        return dict(row)
+    return None
+
+
+def _validate_page_properties(conn, collection_id: int, properties: dict, exclude_page_id: int | None = None) -> None:
+    """Validate submitted property values against the collection's schema.
+
+    Raises ``HTTPException(400)`` with a user-friendly message on the first
+    failure (type, required, unique, min/max).
+    """
+    props = conn.execute(
+        "SELECT * FROM collection_properties WHERE collection_id=?", (collection_id,)
+    ).fetchall()
+
+    for prop in props:
+        ptype = prop["prop_type"]
+        if ptype == "title":
+            continue
+        pid = prop["id"]
+        # Values may be keyed by property id (FlowDeckDB UI) or by name (agent).
+        value = properties.get(str(pid))
+        if value is None:
+            value = properties.get(prop["name"])
+        validation = prop["validation_json"] if "validation_json" in prop.keys() else "{}"
+
+        existing_values = None
+        try:
+            import json as _json
+            vcfg = _json.loads(validation) if validation else {}
+        except Exception:
+            vcfg = {}
+        if vcfg.get("unique"):
+            rows = conn.execute(
+                "SELECT id, property_values_json FROM collection_pages WHERE collection_id=?",
+                (collection_id,),
+            ).fetchall()
+            existing_values = []
+            for r in rows:
+                if exclude_page_id is not None and r["id"] == exclude_page_id:
+                    continue
+                try:
+                    pv = _json.loads(r["property_values_json"] or "{}")
+                except Exception:
+                    pv = {}
+                existing_values.append(pv.get(str(pid)) or pv.get(prop["name"]))
+
+        ok, msg = validate_property_rule(ptype, value, validation, existing_values=existing_values)
+        if not ok:
+            raise HTTPException(status_code=400, detail=f"Property '{prop['name']}': {msg}")
+
+
 # ── API: List & Create (no path params) ──
 
 
@@ -46,7 +108,7 @@ async def list_collections_api(request: Request):
 
 @router.post("/api")
 async def create_collection_api(request: Request):
-    """API: create a new collection."""
+    """API: create a new collection, optionally from a database template."""
     try:
         body = await request.json()
     except Exception:
@@ -60,10 +122,24 @@ async def create_collection_api(request: Request):
     icon = body.get("icon", "📋")
     gitea_owner = body.get("gitea_owner")
     gitea_repo = body.get("gitea_repo")
-    schema_json = json.dumps(body.get("schema", []))
+    schema = body.get("schema", [])
     is_locked = body.get("is_locked", False)
 
     with get_conn() as conn:
+        # Apply a template if requested (provides schema + icon).
+        tpl = _apply_template(conn, body.get("template"))
+        if tpl:
+            if body.get("name"):
+                name = body["name"].strip()
+            description = tpl["description"]
+            icon = tpl.get("icon") or icon
+            try:
+                schema = json.loads(tpl["schema_json"])
+            except (json.JSONDecodeError, TypeError):
+                schema = []
+
+        schema_json = json.dumps(schema)
+
         cur = conn.execute(
             """INSERT INTO collections
                (name, description, icon, schema_json, gitea_owner, gitea_repo, is_locked)
@@ -72,6 +148,8 @@ async def create_collection_api(request: Request):
         )
         collection_id = cur.lastrowid
 
+        materialize_properties(conn, collection_id, schema)
+
         conn.execute(
             """INSERT INTO collection_views
                (collection_id, name, view_type, config_json)
@@ -176,9 +254,18 @@ async def update_page_api(request: Request, page_id: int):
         icon = body.get("icon", existing["icon"])
         position = body.get("position", existing["position"])
         parent_id = body.get("parent_id", existing["parent_id"])
-        property_values = json.dumps(
-            body.get("properties", json.loads(existing["property_values_json"]))
-        )
+
+        if "properties" in body:
+            props = body["properties"]
+        else:
+            try:
+                props = json.loads(existing["property_values_json"])
+            except (json.JSONDecodeError, TypeError):
+                props = {}
+
+        _validate_page_properties(conn, existing["collection_id"], props, exclude_page_id=page_id)
+
+        property_values = json.dumps(props)
 
         conn.execute(
             """UPDATE collection_pages
@@ -289,6 +376,7 @@ async def create_property_api(request: Request, collection_id: int):
     number_format = body.get("number_format", "number")
     required = int(body.get("required", False))
     visible = int(body.get("visible_in_views", True))
+    validation_json = json.dumps(body.get("validation", {}))
 
     with get_conn() as conn:
         coll = conn.execute("SELECT id FROM collections WHERE id=?", (collection_id,)).fetchone()
@@ -304,9 +392,10 @@ async def create_property_api(request: Request, collection_id: int):
             cur = conn.execute(
                 """INSERT INTO collection_properties
                    (collection_id, name, prop_type, options_json, number_format,
-                    position, required, visible_in_views)
-                   VALUES (?, ?, ?, ?, ?, ?, ?, ?)""",
-                (collection_id, name, prop_type, options_json, number_format, max_pos, required, visible),
+                    position, required, visible_in_views, validation_json)
+                   VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)""",
+                (collection_id, name, prop_type, options_json, number_format, max_pos,
+                 required, visible, validation_json),
             )
             conn.commit()
         except Exception:
@@ -335,12 +424,16 @@ async def update_property_api(request: Request, prop_id: int):
         number_format = body.get("number_format", existing["number_format"])
         required = int(body.get("required", existing["required"]))
         visible = int(body.get("visible_in_views", existing["visible_in_views"]))
+        if "validation" in body:
+            validation_json = json.dumps(body.get("validation", {}))
+        else:
+            validation_json = existing["validation_json"] if "validation_json" in existing.keys() else "{}"
 
         conn.execute(
             """UPDATE collection_properties
-               SET name=?, options_json=?, number_format=?, required=?, visible_in_views=?
+               SET name=?, options_json=?, number_format=?, required=?, visible_in_views=?, validation_json=?
                WHERE id=?""",
-            (name, options_json, number_format, required, visible, prop_id),
+            (name, options_json, number_format, required, visible, validation_json, prop_id),
         )
         conn.commit()
 
@@ -964,7 +1057,7 @@ async def toggle_inline(request: Request, collection_id: int):
 
 @router.post("/inline/api")
 async def create_inline_database(request: Request):
-    """API: create an inline database within a parent page."""
+    """API: create an inline database within a parent page (optionally from a template)."""
     try:
         body = await request.json()
     except Exception:
@@ -978,16 +1071,30 @@ async def create_inline_database(request: Request):
     icon = body.get("icon", "📋")
     parent_page_id = body.get("parent_page_id")
     workspace_id = body.get("workspace_id")
+    schema = body.get("schema", [])
 
     with get_conn() as conn:
+        tpl = _apply_template(conn, body.get("template"))
+        if tpl:
+            if body.get("name"):
+                name = body["name"].strip()
+            description = tpl["description"]
+            icon = tpl.get("icon") or icon
+            try:
+                schema = json.loads(tpl["schema_json"])
+            except (json.JSONDecodeError, TypeError):
+                schema = []
+
         cur = conn.execute(
             """INSERT INTO collections
-               (name, description, icon, schema_json, is_inline, parent_page_id)
-               VALUES (?, ?, ?, '[]', 1, ?)""",
-            (name, description, icon, parent_page_id),
+               (name, description, icon, schema_json, is_inline, parent_page_id, workspace_id)
+               VALUES (?, ?, ?, ?, 1, ?, ?)""",
+            (name, description, icon, json.dumps(schema), parent_page_id, workspace_id),
         )
         collection_id = cur.lastrowid
 
+        materialize_properties(conn, collection_id, schema)
+
         # Create default view
         conn.execute(
             """INSERT INTO collection_views
@@ -1004,6 +1111,7 @@ async def create_inline_database(request: Request):
     return {
         "id": collection_id,
         "name": name,
+        "icon": icon,
         "is_inline": True,
         "parent_page_id": parent_page_id,
         "status": "created",
@@ -1763,7 +1871,7 @@ async def create_page_api(request: Request, collection_id: int):
         raise HTTPException(status_code=400, detail="title is required")
 
     icon = body.get("icon", "📄")
-    property_values = json.dumps(body.get("properties", {}))
+    property_values = body.get("properties", {})
     gitea_issue_id = body.get("gitea_issue_id")
     gitea_issue_number = body.get("gitea_issue_number")
 
@@ -1772,6 +1880,8 @@ async def create_page_api(request: Request, collection_id: int):
         if not coll:
             raise HTTPException(status_code=404, detail="Collection not found")
 
+        _validate_page_properties(conn, collection_id, property_values)
+
         max_pos = conn.execute(
             "SELECT COALESCE(MAX(position), -1) + 1 FROM collection_pages WHERE collection_id=?",
             (collection_id,),
@@ -1781,7 +1891,8 @@ async def create_page_api(request: Request, collection_id: int):
             """INSERT INTO collection_pages
                (collection_id, title, icon, position, gitea_issue_id, gitea_issue_number, property_values_json)
                VALUES (?, ?, ?, ?, ?, ?, ?)""",
-            (collection_id, title, icon, max_pos, gitea_issue_id, gitea_issue_number, property_values),
+            (collection_id, title, icon, max_pos, gitea_issue_id, gitea_issue_number,
+             json.dumps(property_values)),
         )
         conn.commit()
         page_id = cur.lastrowid
diff --git a/app/routers/workspace.py b/app/routers/workspace.py
index e840db1..1d6cb01 100644
--- a/app/routers/workspace.py
+++ b/app/routers/workspace.py
@@ -231,8 +231,9 @@ async def create_db_template(request: Request):
     cur = None
     with get_conn() as conn:
         cur = conn.execute(
-            "INSERT INTO database_templates (name, description, schema_json) VALUES (?,?,?)",
-            (body.get("name", "Template"), body.get("description", ""), json.dumps(body.get("schema", []))),
+            "INSERT INTO database_templates (name, description, icon, schema_json) VALUES (?,?,?,?)",
+            (body.get("name", "Template"), body.get("description", ""),
+             body.get("icon", "📋"), json.dumps(body.get("schema", []))),
         )
         conn.commit()
     return {"id": cur.lastrowid, "status": "created"}
@@ -240,22 +241,16 @@ async def create_db_template(request: Request):
 
 @router.post("/templates/database/{tid}/apply")
 async def apply_db_template(request: Request, tid: int):
+    from app.services.db_templates import create_from_template
     body = await request.json() if request.headers.get("content-type") else {}
     name = body.get("name", "New Database")
     with get_conn() as conn:
         tmpl = conn.execute("SELECT * FROM database_templates WHERE id=?", (tid,)).fetchone()
         if not tmpl:
             raise HTTPException(404, "Template not found")
-        cur = conn.execute(
-            "INSERT INTO collections (name, description, icon, schema_json) VALUES (?,?,?,?)",
-            (name, tmpl["description"], "📋", tmpl["schema_json"]),
-        )
-        conn.execute(
-            "INSERT INTO collection_views (collection_id, name, view_type, config_json) VALUES (?,?,?,?)",
-            (cur.lastrowid, "Default View", "table", "{}"),
-        )
+        collection_id = create_from_template(conn, name, dict(tmpl))
         conn.commit()
-    return {"collection_id": cur.lastrowid, "name": name, "status": "created"}
+    return {"collection_id": collection_id, "name": name, "status": "created"}
 
 
 @router.get("/collections/{collection_id}/templates/page")
diff --git a/app/services/db_templates.py b/app/services/db_templates.py
new file mode 100644
index 0000000..249f548
--- /dev/null
+++ b/app/services/db_templates.py
@@ -0,0 +1,201 @@
+"""FlowDeck — Database templates (v5.3.0).
+
+Defines the built-in (seeded) database templates, materializes a template's
+schema into real ``collection_properties`` rows, and creates a collection from
+a template. Templates are stored in ``database_templates`` (name, icon,
+description, schema_json).
+"""
+from __future__ import annotations
+
+import json
+
+# ── Built-in templates ──
+# Each schema entry: {"name", "type", "options"?: [{name, color}]}.
+SEED_TEMPLATES: list[dict] = [
+    {
+        "name": "Project tracker",
+        "icon": "🚀",
+        "description": "Suivi de projets avec statut, priorité et échéances.",
+        "schema": [
+            {"name": "Title", "type": "title"},
+            {"name": "Status", "type": "status", "options": [
+                {"name": "Not started", "color": "gray"},
+                {"name": "In progress", "color": "blue"},
+                {"name": "Done", "color": "green"},
+            ]},
+            {"name": "Priority", "type": "select", "options": [
+                {"name": "Low", "color": "gray"},
+                {"name": "Medium", "color": "yellow"},
+                {"name": "High", "color": "orange"},
+                {"name": "Urgent", "color": "red"},
+            ]},
+            {"name": "Due date", "type": "date"},
+            {"name": "Assignee", "type": "person"},
+            {"name": "Tags", "type": "multi_select"},
+        ],
+    },
+    {
+        "name": "CRM / Contacts",
+        "icon": "👥",
+        "description": "Gestion des contacts et prospects.",
+        "schema": [
+            {"name": "Name", "type": "title"},
+            {"name": "Email", "type": "email"},
+            {"name": "Phone", "type": "phone"},
+            {"name": "Company", "type": "text"},
+            {"name": "Stage", "type": "status", "options": [
+                {"name": "Lead", "color": "gray"},
+                {"name": "Prospect", "color": "blue"},
+                {"name": "Customer", "color": "green"},
+            ]},
+            {"name": "Tags", "type": "multi_select"},
+        ],
+    },
+    {
+        "name": "Task list",
+        "icon": "✅",
+        "description": "Liste de tâches simple avec assignation et échéance.",
+        "schema": [
+            {"name": "Task", "type": "title"},
+            {"name": "Status", "type": "status", "options": [
+                {"name": "To do", "color": "gray"},
+                {"name": "In progress", "color": "blue"},
+                {"name": "Done", "color": "green"},
+            ]},
+            {"name": "Priority", "type": "select", "options": [
+                {"name": "Low", "color": "gray"},
+                {"name": "Medium", "color": "yellow"},
+                {"name": "High", "color": "red"},
+            ]},
+            {"name": "Due date", "type": "date"},
+            {"name": "Assignee", "type": "person"},
+        ],
+    },
+    {
+        "name": "Content calendar",
+        "icon": "📅",
+        "description": "Planification de contenu et de publications.",
+        "schema": [
+            {"name": "Title", "type": "title"},
+            {"name": "Type", "type": "select", "options": [
+                {"name": "Article", "color": "blue"},
+                {"name": "Video", "color": "orange"},
+                {"name": "Social", "color": "green"},
+                {"name": "Newsletter", "color": "purple"},
+            ]},
+            {"name": "Status", "type": "status", "options": [
+                {"name": "Draft", "color": "gray"},
+                {"name": "In review", "color": "yellow"},
+                {"name": "Published", "color": "green"},
+            ]},
+            {"name": "Publish date", "type": "date"},
+            {"name": "Category", "type": "select"},
+        ],
+    },
+    {
+        "name": "Meeting notes",
+        "icon": "🗒️",
+        "description": "Notes de réunion avec participants et décisions.",
+        "schema": [
+            {"name": "Title", "type": "title"},
+            {"name": "Date", "type": "date"},
+            {"name": "Attendees", "type": "person"},
+            {"name": "Status", "type": "status", "options": [
+                {"name": "Scheduled", "color": "gray"},
+                {"name": "Done", "color": "green"},
+            ]},
+            {"name": "Action items", "type": "multi_select"},
+        ],
+    },
+    {
+        "name": "Reading list",
+        "icon": "📚",
+        "description": "Articles, livres et ressources à lire.",
+        "schema": [
+            {"name": "Title", "type": "title"},
+            {"name": "URL", "type": "url"},
+            {"name": "Status", "type": "status", "options": [
+                {"name": "To read", "color": "gray"},
+                {"name": "Reading", "color": "blue"},
+                {"name": "Done", "color": "green"},
+            ]},
+            {"name": "Notes", "type": "text"},
+        ],
+    },
+]
+
+
+def materialize_properties(conn, collection_id: int, schema: list) -> None:
+    """Insert ``collection_properties`` rows from a template ``schema``.
+
+    The ``title`` property is represented by ``collection_pages.title`` and is
+    not created as a column. Rows are inserted in schema order.
+    """
+    position = 0
+    for prop in schema:
+        name = (prop.get("name") or "").strip()
+        if not name:
+            continue
+        prop_type = prop.get("type", "text")
+        if prop_type == "title":
+            continue
+        options = prop.get("options") or []
+        # idempotency guard — skip if a same-named property already exists
+        exists = conn.execute(
+            "SELECT id FROM collection_properties WHERE collection_id=? AND name=?",
+            (collection_id, name),
+        ).fetchone()
+        if exists:
+            continue
+        conn.execute(
+            """INSERT INTO collection_properties
+               (collection_id, name, prop_type, options_json, number_format, position)
+               VALUES (?, ?, ?, ?, 'number', ?)""",
+            (collection_id, name, prop_type, json.dumps(options), position),
+        )
+        position += 1
+
+
+def create_from_template(
+    conn,
+    name: str,
+    template: dict,
+    *,
+    parent_page_id: int | None = None,
+    workspace_id: int | None = None,
+) -> int:
+    """Create a collection from a template (with properties + default view).
+
+    ``template`` may be a DB row (sqlite Row) or a dict; it must expose
+    ``icon``, ``description`` and ``schema_json`` (JSON-encoded schema).
+    """
+    icon = template.get("icon") if isinstance(template, dict) else template["icon"]
+    description = template.get("description") if isinstance(template, dict) else template["description"]
+    schema_json = template.get("schema_json") if isinstance(template, dict) else template["schema_json"]
+    try:
+        schema = json.loads(schema_json)
+    except (json.JSONDecodeError, TypeError):
+        schema = []
+
+    cur = conn.execute(
+        """INSERT INTO collections
+           (name, description, icon, schema_json, is_inline, parent_page_id, workspace_id)
+           VALUES (?, ?, ?, ?, 1, ?, ?)""",
+        (name, description or "", icon or "📋", json.dumps(schema),
+         parent_page_id, workspace_id),
+    )
+    collection_id = cur.lastrowid
+
+    materialize_properties(conn, collection_id, schema)
+
+    conn.execute(
+        """INSERT INTO collection_views
+           (collection_id, name, view_type, config_json)
+           VALUES (?, ?, ?, ?)""",
+        (collection_id, "Default View", "table", json.dumps({
+            "visible_properties": ["Title"],
+            "sorts": [],
+            "filters": [],
+        })),
+    )
+    return collection_id
\ No newline at end of file
diff --git a/app/services/property_types.py b/app/services/property_types.py
index 16fc84e..b7d7b69 100644
--- a/app/services/property_types.py
+++ b/app/services/property_types.py
@@ -149,6 +149,84 @@ def validate_property_value(prop_type: str, value: Any, options: Optional[list]
     return True, ""
 
 
+def parse_validation(validation) -> dict:
+    """Normalize a property's ``validation_json`` into a config dict."""
+    if validation is None:
+        return {}
+    if isinstance(validation, dict):
+        cfg = dict(validation)
+    else:
+        try:
+            cfg = json.loads(validation) if validation else {}
+        except (json.JSONDecodeError, TypeError):
+            cfg = {}
+    return {
+        "required": bool(cfg.get("required", False)),
+        "unique": bool(cfg.get("unique", False)),
+        "min": cfg.get("min"),
+        "max": cfg.get("max"),
+        "min_length": cfg.get("min_length"),
+        "max_length": cfg.get("max_length"),
+    }
+
+
+def validate_property_rule(
+    prop_type: str,
+    value: Any,
+    validation: Optional[dict] = None,
+    *,
+    existing_values: Optional[list] = None,
+) -> tuple[bool, str]:
+    """Validate a property value against type + validation rules.
+
+    Returns ``(ok, error_message)``. ``existing_values`` is used to enforce the
+    ``unique`` rule (a list of the values already stored for that property).
+    """
+    cfg = parse_validation(validation)
+
+    # Type-level validation first.
+    ok, msg = validate_property_value(prop_type, value)
+    if not ok:
+        return False, msg
+
+    # Empty / required
+    is_empty = value is None or value == "" or (isinstance(value, list) and len(value) == 0)
+    if is_empty:
+        if cfg.get("required"):
+            return False, "This property is required"
+        return True, ""
+
+    # Length bounds (string types)
+    if isinstance(value, str):
+        if cfg.get("min_length") is not None and len(value) < int(cfg["min_length"]):
+            return False, f"Must be at least {int(cfg['min_length'])} characters"
+        if cfg.get("max_length") is not None and len(value) > int(cfg["max_length"]):
+            return False, f"Must be at most {int(cfg['max_length'])} characters"
+
+    # Numeric bounds
+    if prop_type == "number" or (isinstance(value, (int, float)) and not isinstance(value, bool)):
+        try:
+            num = float(value)
+        except (ValueError, TypeError):
+            num = None
+        if num is not None:
+            if cfg.get("min") is not None and num < float(cfg["min"]):
+                return False, f"Must be greater than or equal to {cfg['min']}"
+            if cfg.get("max") is not None and num > float(cfg["max"]):
+                return False, f"Must be less than or equal to {cfg['max']}"
+
+    # Unique
+    if cfg.get("unique") and existing_values is not None:
+        norm = str(value).strip().lower()
+        for ev in existing_values:
+            if ev is None:
+                continue
+            if str(ev).strip().lower() == norm:
+                return False, "Value already exists (must be unique)"
+
+    return True, ""
+
+
 def get_auto_property_value(prop_type: str, user: Optional[dict] = None) -> Any:
     """Compute the value of an auto-property."""
     if prop_type == "created_time" or prop_type == "last_edited_time":
diff --git a/app/templates/_database_table_scripts.html b/app/templates/_database_table_scripts.html
index a852af5..3a49931 100644
--- a/app/templates/_database_table_scripts.html
+++ b/app/templates/_database_table_scripts.html
@@ -1,4 +1,5 @@
 <!-- ═══════════ Database Table Scripts — Vanilla JS ═══════════ -->
+<style>.db-cell-invalid{outline:2px solid #e5484d;outline-offset:-1px;border-radius:4px}</style>
 <script>
 (function() {
     'use strict';
@@ -206,7 +207,31 @@
                 cellEl.innerHTML += '<button class="db-open-btn db-open-page-btn db-hover-only" data-page-id="'+pageId+'" title="Open" style="visibility:hidden;margin-left:auto;flex-shrink:0">↗</button>';
             }
             cellEl.onclick = function(e) { if(!state.editingCell && !e.target.closest('.db-open-btn')) startEditCell(pageId,propId,cellEl); };
-            fetch('/db/pages/'+pageId+'/api',{method:'PUT',headers:{'Content-Type':'application/json','X-CSRF-Token':getCsrf()},body:JSON.stringify({title:cp.title,properties:pv})}).catch(function(e){});
+            fetch('/db/pages/'+pageId+'/api',{method:'PUT',headers:{'Content-Type':'application/json','X-CSRF-Token':getCsrf()},body:JSON.stringify({title:cp.title,properties:pv})})
+              .then(function(r){
+                if(!r.ok){
+                  return r.json().then(function(d){ throw {status:r.status, detail:(d&&d.detail)||('Error '+r.status)}; });
+                }
+                cellEl.classList.remove('db-cell-invalid');
+                return r.json();
+              })
+              .catch(function(err){
+                // Validation failed (400) → show message + revert the cell.
+                const msg = (err && err.detail) ? String(err.detail) : ((err&&err.message)||'Failed to save');
+                if(err && err.status===400){
+                  cellEl.classList.add('db-cell-invalid');
+                  cellEl.title = msg;
+                }
+                if(typeof window.showToast==='function') window.showToast('⚠ '+msg,'error');
+                else alert('⚠ '+msg);
+                // Revert to the stored value.
+                const stored = pv[String(propId)];
+                cellEl.innerHTML = '<span class="db-cell-value">'+escHtml(stored||'\u2014')+'</span>';
+                if (prop.prop_type === 'title') {
+                  cellEl.innerHTML += '<button class="db-open-btn db-open-page-btn db-hover-only" data-page-id="'+pageId+'" title="Open" style="visibility:hidden;margin-left:auto;flex-shrink:0">↗</button>';
+                }
+                cellEl.onclick = function(e) { if(!state.editingCell && !e.target.closest('.db-open-btn')) startEditCell(pageId,propId,cellEl); };
+              });
         }
 
         function cancelEditCell() {
@@ -246,6 +271,14 @@
               '<div class="db-modal-body" style="padding:16px">'+
               '<div class="db-modal-field" style="margin-bottom:12px"><label style="display:block;margin-bottom:4px;font-size:12px;color:var(--text-dim)">Name</label><input class="db-prop-name-inline" type="text" placeholder="Property name" style="width:100%;padding:8px 10px;border:1px solid var(--border);border-radius:6px;font-size:14px;box-sizing:border-box"></div>'+
               '<div class="db-modal-field" style="margin-bottom:12px"><label style="display:block;margin-bottom:4px;font-size:12px;color:var(--text-dim)">Type</label><select class="db-prop-type-inline" style="width:100%;padding:8px 10px;border:1px solid var(--border);border-radius:6px;font-size:14px;box-sizing:border-box"><option value="text">Text</option><option value="number">Number</option><option value="select">Select</option><option value="multi_select">Multi-select</option><option value="date">Date</option><option value="checkbox">Checkbox</option><option value="url">URL</option><option value="email">Email</option><option value="phone">Phone</option></select></div>'+
+              '<div style="display:flex;gap:16px;margin-bottom:12px">'+
+                '<label style="display:flex;align-items:center;gap:6px;font-size:12px;color:var(--text)"><input class="db-prop-required-inline" type="checkbox"> Required</label>'+
+                '<label style="display:flex;align-items:center;gap:6px;font-size:12px;color:var(--text)"><input class="db-prop-unique-inline" type="checkbox"> Unique</label>'+
+              '</div>'+
+              '<div style="display:flex;gap:10px;margin-bottom:12px">'+
+                '<div style="flex:1"><label style="display:block;margin-bottom:4px;font-size:12px;color:var(--text-dim)">Min</label><input class="db-prop-min-inline" type="number" placeholder="—" style="width:100%;padding:7px 10px;border:1px solid var(--border);border-radius:6px;font-size:13px;box-sizing:border-box"></div>'+
+                '<div style="flex:1"><label style="display:block;margin-bottom:4px;font-size:12px;color:var(--text-dim)">Max</label><input class="db-prop-max-inline" type="number" placeholder="—" style="width:100%;padding:7px 10px;border:1px solid var(--border);border-radius:6px;font-size:13px;box-sizing:border-box"></div>'+
+              '</div>'+
               '<div style="display:flex;justify-content:flex-end;gap:8px;margin-top:16px"><button class="db-prop-cancel-inline" style="padding:6px 14px;border-radius:6px;border:1px solid var(--border);background:var(--bg-primary);color:var(--text-secondary);font-size:13px;cursor:pointer">Cancel</button><button class="db-prop-create-inline" style="padding:6px 14px;border-radius:6px;border:none;background:var(--accent,#2383E2);color:white;font-size:13px;cursor:pointer">Create</button></div>'+
               '</div></div>';
             document.body.appendChild(modal);
@@ -261,10 +294,17 @@
                 var name = nameInput.value.trim();
                 if(!name) return;
                 var type = modal.querySelector('.db-prop-type-inline').value;
+                var validation = {};
+                if(modal.querySelector('.db-prop-required-inline').checked) validation.required = true;
+                if(modal.querySelector('.db-prop-unique-inline').checked) validation.unique = true;
+                var min = modal.querySelector('.db-prop-min-inline').value;
+                var max = modal.querySelector('.db-prop-max-inline').value;
+                if(min!=='') validation.min = Number(min);
+                if(max!=='') validation.max = Number(max);
                 try {
                     var r = await fetch('/db/'+collectionId+'/properties/api',{
                         method:'POST',headers:{'Content-Type':'application/json','X-CSRF-Token':getCsrf()},
-                        body:JSON.stringify({name:name,prop_type:type})
+                        body:JSON.stringify({name:name,prop_type:type,validation:validation})
                     });
                     var d = await r.json();
                     if(d.id){ state.properties.push(d); render(); modal.remove(); }
diff --git a/app/templates/_page_editor_content.html b/app/templates/_page_editor_content.html
index bca1b2f..669bcb8 100644
--- a/app/templates/_page_editor_content.html
+++ b/app/templates/_page_editor_content.html
@@ -581,4 +581,43 @@
         ></span>
         <span class="statusbar-right" x-text="blocks.length+' blocks'"></span>
     </div>
+
+    <!-- ═══════════ Database template picker (v5.3.0) ═══════════ -->
+    <div class="fd-dbtpl-overlay" id="fd-dbtpl" x-show="dbTplOpen"
+         style="display:none;position:fixed;inset:0;background:rgba(0,0,0,.55);z-index:2100;
+                align-items:flex-start;justify-content:center;padding-top:10vh;opacity:0;transition:opacity .15s ease;"
+         @click.self="closeDbTemplatePicker()">
+      <div class="fd-dbtpl" style="width:620px;max-width:94vw;max-height:76vh;display:flex;flex-direction:column;
+           background:var(--bg-secondary,#232323);border:1px solid var(--border,rgba(255,255,255,.08));border-radius:12px;
+           box-shadow:0 24px 70px rgba(0,0,0,.6);overflow:hidden;">
+        <div style="display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid var(--border);">
+          <h3 style="margin:0;font-size:16px;color:var(--text,#fff);">Create a database</h3>
+          <button class="flowdeck-modal-close" @click="closeDbTemplatePicker()">&times;</button>
+        </div>
+        <div style="padding:12px 20px;overflow-y:auto;">
+          <div x-show="dbTplLoading" style="color:var(--text-dim,#999);font-size:13px;padding:20px 0;text-align:center;">Loading templates…</div>
+          <div x-show="!dbTplLoading">
+            <!-- Blank -->
+            <div class="fd-dbtpl-card" @click="createDbFromTemplate(null)"
+                 style="display:flex;align-items:center;gap:12px;padding:12px 14px;border:1px solid var(--border);border-radius:10px;margin-bottom:10px;cursor:pointer;">
+              <span style="font-size:22px;">📋</span>
+              <div><div style="font-weight:600;color:var(--text,#fff);font-size:14px;">Blank database</div>
+                <div style="font-size:12px;color:var(--text-dim,#999);">Start from an empty database</div></div>
+            </div>
+            <template x-for="t in dbTemplates" :key="t.id">
+              <div class="fd-dbtpl-card" @click="createDbFromTemplate(t.name)"
+                   style="display:flex;align-items:center;gap:12px;padding:12px 14px;border:1px solid var(--border);border-radius:10px;margin-bottom:10px;cursor:pointer;">
+                <span style="font-size:22px;" x-text="t.icon||'📋'"></span>
+                <div style="flex:1;"><div style="font-weight:600;color:var(--text,#fff);font-size:14px;" x-text="t.name"></div>
+                  <div style="font-size:12px;color:var(--text-dim,#999);" x-text="t.description||''"></div></div>
+              </div>
+            </template>
+            <div x-show="!dbTplLoading && !dbTemplates.length" style="color:var(--text-dim,#999);font-size:13px;padding:16px 0;text-align:center;">
+              No templates available
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+
 </div>
diff --git a/app/templates/_page_editor_scripts.html b/app/templates/_page_editor_scripts.html
index a7aac3b..92995d3 100644
--- a/app/templates/_page_editor_scripts.html
+++ b/app/templates/_page_editor_scripts.html
@@ -10,7 +10,8 @@
       {id:'callout',name:'Callout',icon:'lightbulb'},{id:'table_of_contents',name:'Table of contents',icon:'☰'},{id:'math',name:'Math equation',icon:'∑'},
       {id:'columns',name:'Column list',icon:'▮'},{id:'divider',name:'Divider',icon:'—'},{id:'code',name:'Code block',icon:'<>'},
       {id:'table',name:'Table',icon:'⊞'},
-    ]},{name:'MEDIA',items:[{id:'image',name:'Image',icon:'image'}]}];
+    ]},{name:'MEDIA',items:[{id:'image',name:'Image',icon:'image'}]},
+    {name:'DATA',items:[{id:'database',name:'Database / Inline database',icon:'📊'}]}];
 
     let _bid=0;function genId(){return 'b'+(++_bid)+'_'+Date.now().toString(36);}
     function cp(e){const s=window.getSelection();if(!s.rangeCount)return 0;const r=s.getRangeAt(0).cloneRange();r.selectNodeContents(e);r.setEnd(s.getRangeAt(0).endContainer,s.getRangeAt(0).endOffset);return r.toString().length;}
@@ -871,26 +872,48 @@
         },
         deletePage(){this.moreOpen=false;if(!confirm('Move to Trash?'))return;const csrf=document.cookie.match(/csrf_token=([^;]+)/);fetch(`/board/api/pages/${this.pid}/trash`,{method:'POST',headers:{'X-CSRF-Token':csrf?csrf[1]:''}}).then(()=>{window.location.href='/';}).catch(()=>{window.showToast('Failed','error');});},
 
-        // ── v4.6.0: Get Started actions ──
+        // ── v4.6.0 / v5.3.0: Get Started actions — Database (template picker) ──
+        dbTplOpen:false, dbTplLoading:false, dbTemplates:[], dbTplTargetIdx:-1,
         async createDatabase(){
+          this.openDbTemplatePicker(-1);
+        },
+        async openDbTemplatePicker(targetIdx){
+          this.gsMoreOpen=false;
+          this.dbTplOpen=true; this.dbTplTargetIdx=targetIdx; this.dbTplLoading=true;
+          var self=this;
+          try{
+            const r=await fetch('/workspace/templates/database');
+            const d=await r.json();
+            self.dbTemplates=d.templates||[];
+          }catch(e){ self.dbTemplates=[]; }
+          self.dbTplLoading=false;
+          self.$nextTick(()=>{ const f=document.getElementById('fd-dbtpl'); if(f) setTimeout(()=>{f.style.opacity='1';},10); });
+        },
+        closeDbTemplatePicker(){ this.dbTplOpen=false; },
+        async createDbFromTemplate(tplName){
+          const self=this;
+          var name = tplName ? (tplName+' — '+new Date().toLocaleDateString('fr-FR')) : 'Database';
           const csrf=document.cookie.match(/csrf_token=([^;]+)/);
           try{
-            const name='Database';
-            // Create collection via API
-            const r=await fetch('/db/api',{
+            const body={name:name, parent_page_id:this.pid};
+            if(tplName) body.template=tplName;
+            const r=await fetch('/db/inline/api',{
               method:'POST',headers:{'Content-Type':'application/json','X-CSRF-Token':csrf?csrf[1]:''},
-              body:JSON.stringify({name:name})
+              body:JSON.stringify(body)
             });
             const d=await r.json();
             if(d.id){
-              // Add inline database embed block to the page
-              this.blocks.push(this.mkB('embed','',{embed_type:'collection',collection_id:d.id}));
-              this.render(); this.dirty=true; this.autoSave();
-              this.showToast('Database created');
+              const nb=this.mkB('embed','',{embed_type:'collection',collection_id:d.id});
+              this.sync();
+              const idx=this.dbTplTargetIdx>=0?this.dbTplTargetIdx:(this.blocks.length);
+              this.blocks.splice(idx,0,nb);
+              this.dbTplOpen=false;
+              this.dirty=true; this.autoSave(); this.render();
+              this.showToast(tplName?('Database created from template — '+tplName):'Database created');
             }else{
-              this.showToast('Failed to create database');
+              this.showToast(d.detail||'Failed to create database');
             }
-          }catch(e){this.showToast('Error: '+e.message);}
+          }catch(e){ this.showToast('Error: '+e.message); }
         },
         async createForm(){
           const name=prompt('Form name:','New Form');
@@ -979,6 +1002,7 @@
         },
         applySlash(id){
           const idx=SM._i;if(idx<0||idx>=this.blocks.length)return;
+          if(id==='database'){ this.openDbTemplatePicker(idx); return; }
           const block=this.blocks[idx];this.sync();block.content='';
           if(id==='divider'){block.type='divider';this.addAfter(idx,'paragraph');}
           else{block.type=id;if(id==='toggle'){block.expanded=true;block.children=[];}if(id==='to_do')block.checked=false;if(id==='columns')block.children=[{id:genId(),type:'paragraph',content:''}];if(id==='code')block.language='Plain Text';if(id==='table'){block.rows=_tblNew(3,3);block.content='';}}
diff --git a/tests/test_db_advanced.py b/tests/test_db_advanced.py
new file mode 100644
index 0000000..697802d
--- /dev/null
+++ b/tests/test_db_advanced.py
@@ -0,0 +1,155 @@
+"""FlowDeck — v5.3.0 tests: inline databases, database templates, property validation."""
+import json
+import os
+import tempfile
+
+import pytest
+from fastapi.testclient import TestClient
+
+
+@pytest.fixture
+def client():
+    db_file = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
+    db_path = db_file.name
+    db_file.close()
+
+    os.environ["DATABASE_URL"] = f"sqlite:///{db_path}"
+    os.environ["APP_SECRET_KEY"] = "test-secret-for-tests"
+    os.environ["RATE_LIMIT_ENABLED"] = "false"
+
+    from app.main import app
+    from app.db import init_db
+    init_db()
+
+    yield TestClient(app)
+
+    os.unlink(db_path)
+
+
+# ── Database templates ──
+
+def test_seed_templates_available(client):
+    resp = client.get("/workspace/templates/database")
+    assert resp.status_code == 200
+    templates = resp.json()["templates"]
+    names = {t["name"] for t in templates}
+    assert "Project tracker" in names
+    assert "CRM / Contacts" in names
+    for t in templates:
+        assert t.get("icon")
+
+
+def _props(client, cid):
+    return client.get(f"/db/{cid}/properties/api").json()["properties"]
+
+
+def test_create_collection_from_template_materializes_properties(client):
+    resp = client.post("/db/api", json={"name": "My CRM", "template": "CRM / Contacts"})
+    assert resp.status_code == 200
+    cid = resp.json()["id"]
+
+    # Properties materialized (status + person/email etc.), title skipped
+    props = _props(client, cid)
+    names = {p["name"]: p for p in props}
+    assert "Email" in names
+    assert "Stage" in names
+    assert names["Stage"]["prop_type"] == "status"
+    assert "Title" not in names  # title is the row title, not a column
+
+
+def test_create_inline_database_from_template(client):
+    resp = client.post("/db/inline/api", json={"name": "Tasks", "template": "Task list", "parent_page_id": 1})
+    assert resp.status_code == 200
+    cid = resp.json()["id"]
+    assert resp.json()["is_inline"] is True
+
+    props = _props(client, cid)
+    names = {p["name"] for p in props}
+    assert {"Status", "Priority", "Due date"} <= names
+
+
+def test_apply_db_template_endpoint(client):
+    resp = client.get("/workspace/templates/database").json()
+    tpl = next(t for t in resp["templates"] if t["name"] == "Project tracker")
+    r = client.post(f"/workspace/templates/database/{tpl['id']}/apply", json={"name": "Proj"})
+    assert r.status_code == 200
+    cid = r.json()["collection_id"]
+    props = _props(client, cid)
+    names = {p["name"] for p in props}
+    assert {"Status", "Priority", "Assignee"} <= names
+
+
+# ── Property validation ──
+
+def _add_collection(client, name="V"):
+    return client.post("/db/api", json={"name": name}).json()["id"]
+
+
+def test_required_property_validation(client):
+    cid = _add_collection(client)
+    client.post(f"/db/{cid}/properties/api", json={"name": "Email", "prop_type": "email",
+                                                   "validation": {"required": True}})
+
+    # Missing required → 400
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "Row", "properties": {}})
+    assert r.status_code == 400
+    assert "required" in r.json()["detail"].lower()
+
+    # With value → ok
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "Row", "properties": {"Email": "a@b.com"}})
+    assert r.status_code == 200
+
+
+def test_unique_property_validation(client):
+    cid = _add_collection(client)
+    client.post(f"/db/{cid}/properties/api", json={"name": "Code", "prop_type": "text",
+                                                   "validation": {"unique": True}})
+    client.post(f"/db/{cid}/pages/api", json={"title": "R1", "properties": {"Code": "abc"}})
+
+    # Duplicate → 400
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "R2", "properties": {"Code": "abc"}})
+    assert r.status_code == 400
+    assert "unique" in r.json()["detail"].lower()
+
+    # Update to a duplicate also fails
+    pid = client.post(f"/db/{cid}/pages/api", json={"title": "R3", "properties": {"Code": "xyz"}}).json()["id"]
+    r = client.put(f"/db/pages/{pid}/api", json={"properties": {"Code": "abc"}})
+    assert r.status_code == 400
+
+    # Same row keeping its own value is allowed
+    r = client.put(f"/db/pages/{pid}/api", json={"properties": {"Code": "xyz"}})
+    assert r.status_code == 200
+
+
+def test_min_max_validation(client):
+    cid = _add_collection(client)
+    client.post(f"/db/{cid}/properties/api", json={"name": "Score", "prop_type": "number",
+                                                   "validation": {"min": 0, "max": 100}})
+
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "R", "properties": {"Score": -5}})
+    assert r.status_code == 400
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "R", "properties": {"Score": 150}})
+    assert r.status_code == 400
+    r = client.post(f"/db/{cid}/pages/api", json={"title": "R", "properties": {"Score": 50}})
+    assert r.status_code == 200
+
+
+def test_property_validation_persisted_and_readable(client):
+    cid = _add_collection(client)
+    r = client.post(f"/db/{cid}/properties/api", json={"name": "P", "prop_type": "number",
+                                                       "validation": {"min": 1, "max": 9}})
+    pid = r.json()["id"]
+    props = _props(client, cid)
+    p = next(x for x in props if x["id"] == pid)
+    assert json.loads(p["validation_json"]) == {"min": 1, "max": 9}
+
+
+# ── Inline database block data (via /db collection payload) ──
+
+def test_inline_db_collection_payload(client):
+    cid = _add_collection(client)
+    r = client.get(f"/db/{cid}/api")
+    assert r.status_code == 200
+    data = r.json()
+    assert data["collection"]["id"] == cid
+    assert "views" in data
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