feat: auto-fallback to SQLite when embedded SeekDB is unavailable

.env.example

@@ -4,10 +4,11 @@
 # These are the ONLY variables you need to start PowerMem. Everything else has
 # a safe default, so the system runs out of the box:
 #
-#   - Database  -> OceanBase provider with no host configured, which boots
-#                  embedded seekdb on disk at ./seekdb_data (same engine,
-#                  same SQL surface, no separate server). Set OCEANBASE_HOST
-#                  in `.env.example.full` to point at a remote cluster.
+#   - Database  -> platform-aware default. Linux with embedded SeekDB available
+#                  uses OceanBase/SeekDB on disk; other zero-config platforms
+#                  use SQLite at ./data/powermem_dev.db for basic CRUD/search.
+#                  Use OceanBase/SeekDB for Graph Store, sub_stores, sparse
+#                  vectors, and SkillStore.
 #   - Embedder  -> built-in local all-MiniLM-L6-v2 (no API key required;
 #                  model auto-downloads to ~/.cache on first use)
 #   - Reranker / graph store / telemetry / audit -> sensible defaults / off

.env.example.full

@@ -15,9 +15,10 @@
 #   cp .env.example.full .env
 #
 # Notes on defaults:
-#   - Database: DATABASE_PROVIDER=oceanbase with OCEANBASE_HOST left empty,
-#     which boots embedded seekdb on disk (same engine, no separate server).
-#     Set OCEANBASE_HOST to point at a real OceanBase cluster instead.
+#   - Database: platform-aware. Linux with embedded SeekDB available defaults
+#     to OceanBase/SeekDB on disk; other zero-config platforms default to
+#     SQLite for basic local memory CRUD/search. Use OceanBase/SeekDB for the
+#     full feature stack.
 #   - Embedder: built-in `all-MiniLM-L6-v2` (384 dims) running locally with no
 #     API key. Setting EMBEDDING_PROVIDER below switches to a cloud / self-
 #     hosted embedder instead.
@@ -36,14 +37,14 @@
 # =============================================================================
 #
 # DATABASE_PROVIDER — which storage engine PowerMem talks to.
-#   Recommended:  oceanbase  (the OceanBase backend covers both deployment
-#                             shapes: leave OCEANBASE_HOST empty for embedded
-#                             seekdb on disk — zero ops, no separate server —
+#   Recommended:  oceanbase  (full capability stack; leave OCEANBASE_HOST empty
+#                             for embedded SeekDB on supported Linux installs,
 #                             or set OCEANBASE_HOST to point at a remote
 #                             OceanBase cluster)
-#   Other options: sqlite     (smallest footprint, dev-only),
+#   Leave unset to use the platform-aware default.
+#   Other options: sqlite     (smallest footprint, basic local CRUD/search),
 #                  postgres / pgvector (if your stack already runs PostgreSQL)
-DATABASE_PROVIDER=oceanbase
+# DATABASE_PROVIDER=oceanbase
 
 # -----------------------------------------------------------------------------
 # OceanBase — used when DATABASE_PROVIDER=oceanbase. The same provider covers

apps/claude-code-plugin/SETUP.md

@@ -245,8 +245,9 @@ writing. Never silently patch `.env`.**
    with LLM_PROVIDER / LLM_API_KEY or LLM_AUTH_TOKEN / LLM_MODEL set to real
    values (not placeholders
    like `your_api_key_here`), REUSE it — skip directly to step 3a/3b. Only collect
-   what is missing. Use zero-config defaults for everything else (storage = embedded
-   seekdb, embedder = local all-MiniLM-L6-v2) unless I say otherwise.
+   what is missing. Use zero-config defaults for everything else (storage =
+   platform-aware: embedded SeekDB on supported Linux installs, otherwise SQLite
+   basic mode; embedder = local all-MiniLM-L6-v2) unless I say otherwise.
 
    **2a. Auto-detect or manual?** Use AskUserQuestion (single-select):
 
@@ -351,7 +352,9 @@ writing. Never silently patch `.env`.**
       ⚠️ All three extras are required: `[server]` adds fastapi/uvicorn; `[mcp]` adds
       fastmcp, which is checked at import time and calls sys.exit(1) if missing —
       this kills the HTTP server before it can start even in HTTP-only mode;
-      `[seekdb]` adds the embedded seekdb storage backend (default).
+      `[seekdb]` adds the embedded seekdb storage backend. Without it, platforms
+      where embedded SeekDB is unavailable default to SQLite basic mode; use
+      OceanBase/SeekDB for the full capability stack.
     - Immediately after `uv pip install`, detect which Python interpreter was used. Read
       the shebang from the freshly-installed `powermem-server` entry point — this is
       the only reliable way to guarantee that the model-download script, the uv call

dashboard/src/components/system-health-card.tsx

@@ -94,6 +94,12 @@ export function SystemHealthCard({ status }: SystemHealthCardProps) {
 
   const systemStatus = getStatusDisplay(status.status);
   const StatusIcon = systemStatus.icon;
+  const storageCapabilities = status.storage_capabilities;
+  const storageLimitations = storageCapabilities?.limitations ?? [];
+  const showStorageWarning =
+    status.storage_type?.toLowerCase() === "sqlite" ||
+    (storageCapabilities?.provider === "sqlite" &&
+      storageCapabilities.full_stack_available === false);
 
   return (
     <Card>
@@ -143,6 +149,25 @@ export function SystemHealthCard({ status }: SystemHealthCardProps) {
             </div>
           )}
 
+          {showStorageWarning && (
+            <div className="rounded-md border border-yellow-200 bg-yellow-50 px-3 py-2 text-sm text-yellow-900 dark:border-yellow-900/60 dark:bg-yellow-950/40 dark:text-yellow-100">
+              <div className="flex items-start gap-2">
+                <AlertCircle className="mt-0.5 size-4 shrink-0" />
+                <div className="space-y-1">
+                  <p className="font-medium">
+                    {t("dashboard.systemHealth.sqliteWarningTitle")}
+                  </p>
+                  <p>{t("dashboard.systemHealth.sqliteWarningDescription")}</p>
+                  {storageLimitations.length > 0 && (
+                    <p className="text-xs">
+                      {storageLimitations.join("; ")}
+                    </p>
+                  )}
+                </div>
+              </div>
+            </div>
+          )}
+
           {/* Dependencies Table */}
           {status.dependencies &&
             Object.keys(status.dependencies).length > 0 && (

dashboard/src/i18n/locales/en.json

@@ -47,7 +47,9 @@
       "statusDown": "Down",
       "latency": "latency",
       "noStatus": "No status available",
-      "loading": "Loading system status..."
+      "loading": "Loading system status...",
+      "sqliteWarningTitle": "SQLite basic mode",
+      "sqliteWarningDescription": "PowerMem is running on SQLite. Basic memory CRUD and search are available, but the full capability stack requires OceanBase or embedded SeekDB."
     },
     "charts": {
       "growthTrend": "Growth Trend",

dashboard/src/i18n/locales/zh.json

@@ -47,7 +47,9 @@
       "statusDown": "故障",
       "latency": "延迟",
       "noStatus": "暂无状态信息",
-      "loading": "加载系统状态中..."
+      "loading": "加载系统状态中...",
+      "sqliteWarningTitle": "SQLite 基础模式",
+      "sqliteWarningDescription": "PowerMem 当前使用 SQLite。基础记忆 CRUD 与搜索可用，完整能力栈需要切换到 OceanBase 或嵌入式 SeekDB。"
     },
     "charts": {
       "growthTrend": "增长趋势",

dashboard/src/types/api.ts

@@ -15,6 +15,15 @@ export interface SystemStatus {
   version: string;
   storage_type?: string;
   llm_provider?: string;
+  memory_service_ready?: boolean;
+  startup_error?: string;
+  storage_capabilities?: {
+    provider?: string;
+    defaulted: boolean;
+    full_stack_available: boolean;
+    limitations: string[];
+    recommendation?: string;
+  };
   uptime_seconds: number;
   started_at: string;
   dependencies: Record<string, DependencyStatus>;

docs/guides/0003-configuration.md

@@ -91,17 +91,17 @@ memory = Memory(config=config)
 
 ## 1. Database Configuration (Required)
 
-PowerMem requires a database provider to store memories and vectors. Choose one of the supported providers: SQLite (development), OceanBase (production), or PostgreSQL.
+PowerMem requires a database provider to store memories and vectors. The zero-config default is platform-aware: Linux with embedded SeekDB available uses the OceanBase provider in embedded mode; other platforms fall back to SQLite for basic local memory CRUD/search. Choose OceanBase/SeekDB for the full capability stack, or PostgreSQL/pgvector when your deployment already runs PostgreSQL.
 
 ### Common Database Settings
 
 | Configuration | Type | Required | Default | Description |
 |--------------|------|----------|---------|-------------|
-| `DATABASE_PROVIDER` | string | Yes | `sqlite` | Database provider to use. Options: `sqlite`, `oceanbase`, `postgres` |
+| `DATABASE_PROVIDER` | string | No | platform-aware | Database provider to use. Options: `sqlite`, `oceanbase`, `postgres` |
 
 ### SQLite Configuration
 
-SQLite is the default database provider, recommended for development and single-user applications.
+SQLite is the fallback default when embedded SeekDB is unavailable. It is recommended for development and single-user basic memory CRUD/search. Graph Store, sub_stores, sparse vector search, and SkillStore require OceanBase or embedded SeekDB.
 
 | Configuration | Type | Required | Default | Description |
 |--------------|------|----------|---------|-------------|
@@ -147,15 +147,15 @@ config = {
 
 ### OceanBase Configuration
 
-OceanBase is recommended for production deployments and enterprise applications with high-scale requirements.
+OceanBase is recommended for production deployments and for the full PowerMem capability stack. With `OCEANBASE_HOST` empty, the OceanBase provider uses embedded SeekDB when the native dependency is available. Set `OCEANBASE_HOST` for a remote OceanBase cluster.
 
 | Configuration | Type | Required | Default | Description |
 |--------------|------|----------|---------|-------------|
-| `OCEANBASE_HOST` | string | Yes* | `127.0.0.1` | OceanBase server hostname or IP address. Required when `DATABASE_PROVIDER=oceanbase` |
-| `OCEANBASE_PORT` | integer | Yes* | `2881` | OceanBase server port. Required when `DATABASE_PROVIDER=oceanbase` |
-| `OCEANBASE_USER` | string | Yes* | `root` | Database username. Required when `DATABASE_PROVIDER=oceanbase` |
-| `OCEANBASE_PASSWORD` | string | Yes* | - | Database password. Required when `DATABASE_PROVIDER=oceanbase` |
-| `OCEANBASE_DATABASE` | string | Yes* | `powermem` | Database name. Required when `DATABASE_PROVIDER=oceanbase` |
+| `OCEANBASE_HOST` | string | No* | empty | OceanBase server hostname or IP address. Empty means embedded SeekDB mode; remote mode requires a host |
+| `OCEANBASE_PORT` | integer | Yes* | `2881` | OceanBase server port. Required in remote mode |
+| `OCEANBASE_USER` | string | Yes* | `root@test` | Database username. Required in remote mode |
+| `OCEANBASE_PASSWORD` | string | No | - | Database password. Required if your remote cluster needs one |
+| `OCEANBASE_DATABASE` | string | Yes* | `test` | Database name |
 | `OCEANBASE_COLLECTION` | string | No | `memories` | Collection/table name for storing memories |
 | `OCEANBASE_INDEX_TYPE` | string | No | `IVF_FLAT` | Vector index type. Options: `IVF_FLAT`, `HNSW`, etc. |
 | `OCEANBASE_VECTOR_METRIC_TYPE` | string | No | `cosine` | Vector similarity metric. Options: `cosine`, `euclidean`, `dot_product` |

src/powermem/cli/commands/config.py

@@ -23,6 +23,12 @@
     print_warning,
     print_info,
 )
+from powermem.platform_defaults import (
+    default_database_provider,
+    embedded_seekdb_available,
+    embedded_seekdb_unavailable_message,
+    sqlite_capability_warning,
+)
 
 logger = logging.getLogger(__name__)
 from ..utils.envfile import read_env_file, update_env_file
@@ -295,11 +301,19 @@ def _validate_loaded_config(config: Dict[str, Any], strict: bool) -> Dict[str, A
         provider = vector_store_config.get("provider", "")
         inner_config = vector_store_config.get("config", {})
         if provider == "oceanbase":
-            required_fields = ["host", "port", "user", "db_name"]
             conn_args = inner_config.get("connection_args", {})
-            for field in required_fields:
-                if not conn_args.get(field):
-                    errors.append(f"OceanBase connection missing: {field}")
+            host = conn_args.get("host") or inner_config.get("host")
+            if host:
+                required_fields = ["port", "user", "db_name"]
+                for field in required_fields:
+                    if not (conn_args.get(field) or inner_config.get(field)):
+                        errors.append(f"OceanBase connection missing: {field}")
+            elif not embedded_seekdb_available():
+                errors.append(embedded_seekdb_unavailable_message())
+        elif provider == "sqlite":
+            warning = sqlite_capability_warning(provider, defaulted=not bool(os.environ.get("DATABASE_PROVIDER")))
+            if warning:
+                warnings.append(warning)
         elif provider in ("postgres", "pgvector"):
             required_fields = ["host", "port", "user", "dbname"]
             for field in required_fields:
@@ -795,7 +809,7 @@ def _discover_env_example(start_dir: Path, max_parent_levels: int = 8) -> Option
 
 def _wizard_database(existing: Dict[str, str]) -> Dict[str, str]:
     updates: Dict[str, str] = {}
-    provider_default = existing.get("DATABASE_PROVIDER") or "sqlite"
+    provider_default = existing.get("DATABASE_PROVIDER") or default_database_provider()
     provider = click.prompt(
         "Database provider",
         type=click.Choice(["oceanbase", "postgres", "sqlite"], case_sensitive=False),
@@ -909,7 +923,7 @@ def _wizard_database_quickstart(existing: Dict[str, str]) -> Dict[str, str]:
     This intentionally avoids optional knobs (WAL/timeout/collection/etc.).
     """
     updates: Dict[str, str] = {}
-    provider_default = existing.get("DATABASE_PROVIDER") or "sqlite"
+    provider_default = existing.get("DATABASE_PROVIDER") or default_database_provider()
     provider = click.prompt(
         "Database provider",
         type=click.Choice(["sqlite", "oceanbase", "postgres"], case_sensitive=False),
@@ -1278,7 +1292,7 @@ def init_cmd(ctx: CLIContext, env_file: Optional[str], dry_run: bool, test: bool
             emb_updates = _wizard_embedder_quickstart(existing, llm_updates=llm_updates)
             updates.update(emb_updates)
 
-            db_provider = updates.get("DATABASE_PROVIDER") or existing.get("DATABASE_PROVIDER") or "sqlite"
+            db_provider = updates.get("DATABASE_PROVIDER") or existing.get("DATABASE_PROVIDER") or default_database_provider()
             dims = emb_updates.get("EMBEDDING_DIMS")
             if dims:
                 updates.update(_sync_vector_dims_quickstart(db_provider=db_provider, dims=dims))
@@ -1293,7 +1307,7 @@ def init_cmd(ctx: CLIContext, env_file: Optional[str], dry_run: bool, test: bool
                 emb_updates = _wizard_embedder(existing, llm_updates=llm_updates)
                 updates.update(emb_updates)
 
-                db_provider = updates.get("DATABASE_PROVIDER") or existing.get("DATABASE_PROVIDER") or "sqlite"
+                db_provider = updates.get("DATABASE_PROVIDER") or existing.get("DATABASE_PROVIDER") or default_database_provider()
                 dims = emb_updates.get("EMBEDDING_DIMS")
                 if dims:
                     updates.update(_maybe_sync_vector_dims(db_provider=db_provider, dims=dims))