diff --git a/packages/client-common/__tests__/integration/auth.test.ts b/packages/client-common/__tests__/integration/auth.test.ts
index 3a734cc3..9e014617 100644
--- a/packages/client-common/__tests__/integration/auth.test.ts
+++ b/packages/client-common/__tests__/integration/auth.test.ts
@@ -1,18 +1,21 @@
 import { type ClickHouseClient } from '@clickhouse/client-common'
-import { createTestClient } from '../utils'
+import { createSimpleTable } from '@test/fixtures/simple_table'
+import { getAuthFromEnv } from '@test/utils/env'
+import { createTestClient, guid } from '../utils'
 
 describe('authentication', () => {
   let client: ClickHouseClient
-  afterEach(async () => {
-    await client.close()
-  })
-
-  it('provides authentication error details', async () => {
+  beforeEach(() => {
     client = createTestClient({
       username: 'gibberish',
       password: 'gibberish',
     })
+  })
+  afterEach(async () => {
+    await client.close()
+  })
 
+  it('provides authentication error details', async () => {
     await expectAsync(
       client.query({
         query: 'SELECT number FROM system.numbers LIMIT 3',
@@ -25,4 +28,70 @@ describe('authentication', () => {
       }),
     )
   })
+
+  describe('auth override', () => {
+    let defaultClient: ClickHouseClient
+    beforeAll(() => {
+      defaultClient = createTestClient()
+    })
+    afterAll(async () => {
+      await defaultClient.close()
+    })
+
+    let tableName: string
+    const values = [
+      {
+        id: '1',
+        name: 'foo',
+        sku: [3, 4],
+      },
+    ]
+    const auth = getAuthFromEnv()
+
+    it('should with with insert and select', async () => {
+      tableName = `simple_table_${guid()}`
+      await createSimpleTable(defaultClient, tableName)
+      await client.insert({
+        table: tableName,
+        format: 'JSONEachRow',
+        values,
+        auth,
+      })
+      const rs = await client.query({
+        query: `SELECT * FROM ${tableName} ORDER BY id ASC`,
+        format: 'JSONEachRow',
+        auth,
+      })
+      expect(await rs.json()).toEqual(values)
+    })
+
+    it('should work with command and select', async () => {
+      tableName = `simple_table_${guid()}`
+      await createSimpleTable(defaultClient, tableName)
+      await client.command({
+        query: `INSERT INTO ${tableName} VALUES (1, 'foo', [3, 4])`,
+        auth,
+      })
+      const rs = await client.query({
+        query: `SELECT * FROM ${tableName} ORDER BY id ASC`,
+        format: 'JSONEachRow',
+        auth,
+      })
+      expect(await rs.json()).toEqual(values)
+    })
+
+    it('should work with exec', async () => {
+      const { stream } = await client.exec({
+        query: 'SELECT 42, 144 FORMAT CSV',
+        auth,
+      })
+      let result = ''
+      const textDecoder = new TextDecoder()
+      // @ts-expect-error - ReadableStream (Web) or Stream.Readable (Node.js); same API.
+      for await (const chunk of stream) {
+        result += textDecoder.decode(chunk, { stream: true })
+      }
+      expect(result).toEqual('42,144\n')
+    })
+  })
 })
diff --git a/packages/client-common/__tests__/utils/client.ts b/packages/client-common/__tests__/utils/client.ts
index f3e906d7..a29bd5dd 100644
--- a/packages/client-common/__tests__/utils/client.ts
+++ b/packages/client-common/__tests__/utils/client.ts
@@ -4,7 +4,7 @@ import type {
   ClickHouseClient,
   ClickHouseSettings,
 } from '@clickhouse/client-common'
-import { getFromEnv } from './env'
+import { EnvKeys, getFromEnv } from './env'
 import { guid } from './guid'
 import {
   getClickHouseTestEnvironment,
@@ -55,8 +55,8 @@ export function createTestClient<Stream = unknown>(
   }
   if (isCloudTestEnv()) {
     const cloudConfig: BaseClickHouseClientConfigOptions = {
-      url: `https://${getFromEnv('CLICKHOUSE_CLOUD_HOST')}:8443`,
-      password: getFromEnv('CLICKHOUSE_CLOUD_PASSWORD'),
+      url: `https://${getFromEnv(EnvKeys.host)}:8443`,
+      password: getFromEnv(EnvKeys.password),
       database: databaseName,
       ...logging,
       ...config,
diff --git a/packages/client-common/__tests__/utils/env.ts b/packages/client-common/__tests__/utils/env.ts
index 981897bc..c1d7955c 100644
--- a/packages/client-common/__tests__/utils/env.ts
+++ b/packages/client-common/__tests__/utils/env.ts
@@ -1,3 +1,9 @@
+export const EnvKeys = {
+  host: 'CLICKHOUSE_CLOUD_HOST',
+  username: 'CLICKHOUSE_CLOUD_USERNAME',
+  password: 'CLICKHOUSE_CLOUD_PASSWORD',
+}
+
 export function getFromEnv(key: string): string {
   const value = process.env[key]
   if (value === undefined) {
@@ -5,3 +11,9 @@ export function getFromEnv(key: string): string {
   }
   return value
 }
+
+export function getAuthFromEnv() {
+  const username = process.env[EnvKeys.username]
+  const password = process.env[EnvKeys.password]
+  return { username: username ?? 'default', password: password ?? '' }
+}
diff --git a/packages/client-web/src/connection/web_connection.ts b/packages/client-web/src/connection/web_connection.ts
index 9a9214d1..d91085d3 100644
--- a/packages/client-web/src/connection/web_connection.ts
+++ b/packages/client-web/src/connection/web_connection.ts
@@ -168,7 +168,13 @@ export class WebConnection implements Connection<ReadableStream> {
 
     try {
       const headers = withCompressionHeaders({
-        headers: this.defaultHeaders,
+        headers:
+          params?.auth !== undefined
+            ? {
+                ...this.defaultHeaders,
+                Authorization: `Basic ${btoa(`${params.auth.username}:${params.auth.password}`)}`,
+              }
+            : this.defaultHeaders,
         compress_request: false,
         decompress_response: this.params.compression.decompress_response,
       })