diff --git a/README.md b/README.md
index c2881d7c..42d45f93 100644
--- a/README.md
+++ b/README.md
@@ -100,12 +100,14 @@ For SQLite:
 
 ```bash
 npm install better-sqlite3
+npm install -D @types/better-sqlite3
 ```
 
 For Postgres:
 
 ```bash
-npm install pg
+npm install pg pg-connection-string
+npm install -D @types/pg
 ```
 
 ## Pushing schema to the database
@@ -132,14 +134,32 @@ A `schema.ts` file will be created inside the `zenstack` folder. The file should
 
 ## Creating ZenStack client
 
-Now you can use the compiled TypeScript schema to instantiate a database client:
+Now you can use the compiled TypeScript schema to instantiate a database client.
+
+### SQLite
 
 ```ts
 import { ZenStackClient } from '@zenstackhq/runtime';
 import { schema } from './zenstack/schema';
+import SQLite from 'better-sqlite3';
 
 const client = new ZenStackClient(schema, {
-    dialectConfig: { ... }
+    dialectConfig: { database: new SQLite('./dev.db') },
+});
+```
+
+### Postgres
+
+```ts
+import { ZenStackClient } from '@zenstackhq/runtime';
+import { schema } from './zenstack/schema';
+import { Pool } from 'pg';
+import { parseIntoClientConfig } from 'pg-connection-string';
+
+const client = new ZenStackClient(schema, {
+    dialectConfig: {
+        pool: new Pool(parseIntoClientConfig(process.env.DATABASE_URL)),
+    },
 });
 ```
 
@@ -376,6 +396,7 @@ See [Prisma Migrate](https://www.prisma.io/docs/orm/prisma-migrate) documentatio
 
 # Limitations
 
-1. Only SQLite (better-sqlite3) and Postgres (pg) database providers are supported.
+1. Only SQLite (better-sqlite3) and Postgres (pg) database providers are supported for now.
 1. Prisma client extensions are not supported.
 1. Prisma custom generators are not supported (may add support in the future).
+1. [Filtering on JSON fields](https://www.prisma.io/docs/orm/prisma-client/special-fields-and-types/working-with-json-fields#filter-on-a-json-field-advanced) is not supported yet.
diff --git a/TODO.md b/TODO.md
index ffaf68d7..fdc34f53 100644
--- a/TODO.md
+++ b/TODO.md
@@ -6,7 +6,7 @@
     -   [x] generate
     -   [x] migrate
     -   [x] info
-    -   [ ] init
+    -   [x] init
 -   [ ] ORM
     -   [x] Create
         -   [x] Input validation
@@ -36,6 +36,7 @@
             -   [x] Sorting
             -   [x] Pagination
         -   [x] Distinct
+        -   [ ] JSON filtering
     -   [x] Update
         -   [x] Input validation
         -   [x] Top-level
@@ -65,7 +66,6 @@
         -   [ ] Error system
         -   [x] Custom table name
         -   [x] Custom field name
-        -   [ ] Strict undefined check
         -   [ ] Implement changesets
 -   [ ] Polymorphism
 -   [ ] Validation
diff --git a/package.json b/package.json
index 3d7a55f5..171f319c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "zenstack-v3",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "ZenStack",
     "packageManager": "pnpm@10.12.1",
     "scripts": {
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 10bda869..d648d1eb 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -3,7 +3,7 @@
     "publisher": "zenstack",
     "displayName": "ZenStack CLI",
     "description": "FullStack database toolkit with built-in access control and automatic API generation.",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "type": "module",
     "author": {
         "name": "ZenStack Team"
diff --git a/packages/create-zenstack/package.json b/packages/create-zenstack/package.json
index 09577002..77fdbe70 100644
--- a/packages/create-zenstack/package.json
+++ b/packages/create-zenstack/package.json
@@ -1,6 +1,6 @@
 {
     "name": "create-zenstack",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "Create a new ZenStack project",
     "type": "module",
     "scripts": {
diff --git a/packages/language/package.json b/packages/language/package.json
index bc4a1614..3f68cf9b 100644
--- a/packages/language/package.json
+++ b/packages/language/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@zenstackhq/language",
     "description": "ZenStack ZModel language specification",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "license": "MIT",
     "author": "ZenStack Team",
     "files": [
diff --git a/packages/runtime/package.json b/packages/runtime/package.json
index f7860645..df8cddc3 100644
--- a/packages/runtime/package.json
+++ b/packages/runtime/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@zenstackhq/runtime",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "ZenStack Runtime",
     "type": "module",
     "scripts": {
diff --git a/packages/runtime/src/client/options.ts b/packages/runtime/src/client/options.ts
index 6300d86e..81f91528 100644
--- a/packages/runtime/src/client/options.ts
+++ b/packages/runtime/src/client/options.ts
@@ -24,7 +24,7 @@ import type { ToKyselySchema } from './query-builder';
 type DialectConfig<Provider extends DataSourceProvider> =
     Provider['type'] extends 'sqlite'
         ? Optional<SqliteDialectConfig, 'database'>
-        : Provider extends 'postgresql'
+        : Provider['type'] extends 'postgresql'
         ? Optional<PostgresDialectConfig, 'pool'>
         : never;
 
diff --git a/packages/runtime/test/client-api/filter.test.ts b/packages/runtime/test/client-api/filter.test.ts
index f4925442..9c27350b 100644
--- a/packages/runtime/test/client-api/filter.test.ts
+++ b/packages/runtime/test/client-api/filter.test.ts
@@ -549,6 +549,13 @@ describe.each(createClientSpecs(PG_DB_NAME))(
             ).toResolveTruthy();
         });
 
+        it('ignores undefined filters', async () => {
+            await createUser();
+            await expect(
+                client.user.findMany({ where: { id: undefined } })
+            ).toResolveWithLength(1);
+        });
+
         // TODO: filter for bigint, decimal, bytes
     }
 );
diff --git a/packages/runtime/test/client-api/find.test.ts b/packages/runtime/test/client-api/find.test.ts
index e63e6fba..80b59055 100644
--- a/packages/runtime/test/client-api/find.test.ts
+++ b/packages/runtime/test/client-api/find.test.ts
@@ -30,6 +30,7 @@ describe.each(createClientSpecs(PG_DB_NAME))(
             r = await client.user.findMany();
             expect(r).toHaveLength(1);
             expect(r[0]?.createdAt).toBeInstanceOf(Date);
+
             r = await client.user.findMany({ where: { id: user.id } });
             expect(r).toHaveLength(1);
 
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 5ba4a8f4..ee3331b5 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@zenstackhq/sdk",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "ZenStack SDK",
     "type": "module",
     "scripts": {
diff --git a/packages/tanstack-query/package.json b/packages/tanstack-query/package.json
index 70dabd37..08627453 100644
--- a/packages/tanstack-query/package.json
+++ b/packages/tanstack-query/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@zenstackhq/tanstack-query",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "",
     "main": "index.js",
     "type": "module",
diff --git a/packages/testtools/package.json b/packages/testtools/package.json
index df9f4fb4..290c771d 100644
--- a/packages/testtools/package.json
+++ b/packages/testtools/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@zenstackhq/testtools",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "ZenStack Test Tools",
     "type": "module",
     "scripts": {
diff --git a/packages/zod/package.json b/packages/zod/package.json
index 413c9202..254731b4 100644
--- a/packages/zod/package.json
+++ b/packages/zod/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@zenstackhq/zod",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "",
     "type": "module",
     "main": "index.js",
diff --git a/samples/blog/package.json b/samples/blog/package.json
index bbd6f6d9..db96353a 100644
--- a/samples/blog/package.json
+++ b/samples/blog/package.json
@@ -1,6 +1,6 @@
 {
     "name": "sample-todo",
-    "version": "3.0.0-alpha.2",
+    "version": "3.0.0-alpha.4",
     "description": "",
     "main": "index.js",
     "scripts": {