diff --git a/apps/client-standalone/src/test_setup.ts b/apps/client-standalone/src/test_setup.ts
new file mode 100644
index 0000000000..4e81a69f35
--- /dev/null
+++ b/apps/client-standalone/src/test_setup.ts
@@ -0,0 +1,102 @@
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+
+import { initializeCore } from "@triliumnext/core";
+import schemaSql from "@triliumnext/core/src/assets/schema.sql?raw";
+import { beforeAll } from "vitest";
+
+import BrowserExecutionContext from "./lightweight/cls_provider.js";
+import BrowserCryptoProvider from "./lightweight/crypto_provider.js";
+import BrowserSqlProvider from "./lightweight/sql_provider.js";
+import BrowserZipProvider from "./lightweight/zip_provider.js";
+
+// =============================================================================
+// SQLite WASM compatibility shims
+// =============================================================================
+// The @sqlite.org/sqlite-wasm package loads its .wasm via fetch, and its
+// bundled `instantiateWasm` hook overrides any user-supplied alternative.
+// Two things go wrong under vitest + happy-dom:
+//   1. happy-dom's `fetch()` refuses `file://` URLs.
+//   2. happy-dom installs its own Response global, which Node's
+//      `WebAssembly.instantiateStreaming` rejects ("Received an instance of
+//      Response" — it wants undici's Response).
+// We intercept fetch for file:// URLs ourselves and force instantiateStreaming
+// to fall back to the ArrayBuffer path.
+const fileFetchCache = new Map<string, ArrayBuffer>();
+
+function readFileAsArrayBuffer(url: string): ArrayBuffer {
+    let cached = fileFetchCache.get(url);
+    if (!cached) {
+        const bytes = readFileSync(fileURLToPath(url));
+        cached = bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + bytes.byteLength) as ArrayBuffer;
+        fileFetchCache.set(url, cached);
+    }
+    return cached;
+}
+
+const originalFetch = globalThis.fetch;
+globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+    const url = typeof input === "string"
+        ? input
+        : input instanceof URL
+            ? input.href
+            : input.url;
+
+    if (url.startsWith("file://")) {
+        const body = readFileAsArrayBuffer(url);
+        return new Response(body, {
+            status: 200,
+            headers: { "Content-Type": "application/wasm" }
+        });
+    }
+
+    return originalFetch(input as RequestInfo, init);
+}) as typeof fetch;
+
+WebAssembly.instantiateStreaming = (async (source, importObject) => {
+    const response = await source;
+    const bytes = await response.arrayBuffer();
+    return WebAssembly.instantiate(bytes, importObject);
+}) as typeof WebAssembly.instantiateStreaming;
+
+// =============================================================================
+// Core initialization for standalone-flavored tests
+// =============================================================================
+// Mirror what apps/client-standalone/src/local-server-worker.ts does at
+// startup, but without messaging / requests / OPFS / demo archives. We just
+// need core to be initialized so that pure-becca / pure-search tests can run.
+
+beforeAll(async () => {
+    const sqlProvider = new BrowserSqlProvider();
+    await sqlProvider.initWasm();
+    sqlProvider.loadFromMemory();
+    // Apply the schema so search/becca tests that touch SQL find real tables.
+    sqlProvider.exec(schemaSql);
+
+    await initializeCore({
+        executionContext: new BrowserExecutionContext(),
+        crypto: new BrowserCryptoProvider(),
+        zip: new BrowserZipProvider(),
+        zipExportProviderFactory: (
+            await import("./lightweight/zip_export_provider_factory.js")
+        ).standaloneZipExportProviderFactory,
+        // Stub translations: pure-becca tests don't need real i18n strings.
+        translations: async () => undefined,
+        platform: {
+            isElectron: false,
+            isMac: false,
+            isWindows: false,
+            crash: (msg: string) => {
+                throw new Error(`Platform crash: ${msg}`);
+            },
+            getEnv: () => undefined
+        },
+        schema: schemaSql,
+        dbConfig: {
+            provider: sqlProvider,
+            isReadOnly: false,
+            onTransactionCommit: () => {},
+            onTransactionRollback: () => {}
+        }
+    });
+});
diff --git a/apps/client-standalone/vite.config.mts b/apps/client-standalone/vite.config.mts
index 5f004c6047..ea92dd7855 100644
--- a/apps/client-standalone/vite.config.mts
+++ b/apps/client-standalone/vite.config.mts
@@ -183,7 +183,27 @@ export default defineConfig(() => ({
         }
     },
     test: {
-        environment: "happy-dom"
+        environment: "happy-dom",
+        setupFiles: [join(__dirname, "src/test_setup.ts")],
+        dir: join(__dirname),
+        include: [
+            "src/**/*.{test,spec}.{ts,tsx}",
+            "../../packages/trilium-core/src/**/*.{test,spec}.{ts,tsx}"
+        ],
+        server: {
+            deps: {
+                inline: ["@sqlite.org/sqlite-wasm"]
+            }
+        },
+        alias: {
+            // The package's `node.mjs` entry references a non-existent
+            // `sqlite3-node.mjs`. Force the browser-style entry which works
+            // under Node + happy-dom too.
+            "@sqlite.org/sqlite-wasm": join(
+                __dirname,
+                "../../node_modules/@sqlite.org/sqlite-wasm/index.mjs"
+            )
+        }
     },
     define: {
         "process.env.IS_PREACT": JSON.stringify("true"),