diff --git a/docs/reference/index.html b/docs/reference/index.html
index 76ca5c1c..03a1800e 100644
--- a/docs/reference/index.html
+++ b/docs/reference/index.html
@@ -3004,7 +3004,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
@@ -10268,7 +10268,7 @@ <h3>Methods</h3>
 <a href="https://api.slack.com/methods/chat.scheduledMessages.list">https://api.slack.com/methods/chat.scheduledMessages.list</a></p></div>
 </dd>
 <dt id="slack_sdk.WebClient.chat_startStream"><code class="name flex">
-<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str | None = None,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="web/slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
+<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="web/slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
 </code></dt>
 <dd>
 <details class="source">
@@ -10279,7 +10279,7 @@ <h3>Methods</h3>
     self,
     *,
     channel: str,
-    thread_ts: Optional[str] = None,
+    thread_ts: str,
     markdown_text: Optional[str] = None,
     recipient_team_id: Optional[str] = None,
     recipient_user_id: Optional[str] = None,
diff --git a/docs/reference/oauth/installation_store/file/index.html b/docs/reference/oauth/installation_store/file/index.html
index 7658ddd9..1091d357 100644
--- a/docs/reference/oauth/installation_store/file/index.html
+++ b/docs/reference/oauth/installation_store/file/index.html
@@ -48,7 +48,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
 <dl>
 <dt id="slack_sdk.oauth.installation_store.file.FileInstallationStore"><code class="flex name class">
 <span>class <span class="ident">FileInstallationStore</span></span>
-<span>(</span><span>*,<br>base_dir: str = '/Users/eden.zimbelman/.bolt-app-installation',<br>historical_data_enabled: bool = True,<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.installation_store.file (WARNING)&gt;)</span>
+<span>(</span><span>*,<br>base_dir: str = '/Users/michael.brooks/.bolt-app-installation',<br>historical_data_enabled: bool = True,<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.installation_store.file (WARNING)&gt;)</span>
 </code></dt>
 <dd>
 <details class="source">
diff --git a/docs/reference/oauth/installation_store/index.html b/docs/reference/oauth/installation_store/index.html
index 5865522c..aece243e 100644
--- a/docs/reference/oauth/installation_store/index.html
+++ b/docs/reference/oauth/installation_store/index.html
@@ -327,7 +327,7 @@ <h3>Methods</h3>
 </dd>
 <dt id="slack_sdk.oauth.installation_store.FileInstallationStore"><code class="flex name class">
 <span>class <span class="ident">FileInstallationStore</span></span>
-<span>(</span><span>*,<br>base_dir: str = '/Users/eden.zimbelman/.bolt-app-installation',<br>historical_data_enabled: bool = True,<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.installation_store.file (WARNING)&gt;)</span>
+<span>(</span><span>*,<br>base_dir: str = '/Users/michael.brooks/.bolt-app-installation',<br>historical_data_enabled: bool = True,<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.installation_store.file (WARNING)&gt;)</span>
 </code></dt>
 <dd>
 <details class="source">
diff --git a/docs/reference/oauth/state_store/file/index.html b/docs/reference/oauth/state_store/file/index.html
index 33ac16d8..d91be8db 100644
--- a/docs/reference/oauth/state_store/file/index.html
+++ b/docs/reference/oauth/state_store/file/index.html
@@ -48,7 +48,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
 <dl>
 <dt id="slack_sdk.oauth.state_store.file.FileOAuthStateStore"><code class="flex name class">
 <span>class <span class="ident">FileOAuthStateStore</span></span>
-<span>(</span><span>*,<br>expiration_seconds: int,<br>base_dir: str = '/Users/eden.zimbelman/.bolt-app-oauth-state',<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.state_store.file (WARNING)&gt;)</span>
+<span>(</span><span>*,<br>expiration_seconds: int,<br>base_dir: str = '/Users/michael.brooks/.bolt-app-oauth-state',<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.state_store.file (WARNING)&gt;)</span>
 </code></dt>
 <dd>
 <details class="source">
diff --git a/docs/reference/oauth/state_store/index.html b/docs/reference/oauth/state_store/index.html
index efb7d1cf..a2f5a251 100644
--- a/docs/reference/oauth/state_store/index.html
+++ b/docs/reference/oauth/state_store/index.html
@@ -77,7 +77,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
 <dl>
 <dt id="slack_sdk.oauth.state_store.FileOAuthStateStore"><code class="flex name class">
 <span>class <span class="ident">FileOAuthStateStore</span></span>
-<span>(</span><span>*,<br>expiration_seconds: int,<br>base_dir: str = '/Users/eden.zimbelman/.bolt-app-oauth-state',<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.state_store.file (WARNING)&gt;)</span>
+<span>(</span><span>*,<br>expiration_seconds: int,<br>base_dir: str = '/Users/michael.brooks/.bolt-app-oauth-state',<br>client_id: str | None = None,<br>logger: logging.Logger = &lt;Logger slack_sdk.oauth.state_store.file (WARNING)&gt;)</span>
 </code></dt>
 <dd>
 <details class="source">
diff --git a/docs/reference/web/async_client.html b/docs/reference/web/async_client.html
index e87f6550..a75296b8 100644
--- a/docs/reference/web/async_client.html
+++ b/docs/reference/web/async_client.html
@@ -2900,7 +2900,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
@@ -10164,7 +10164,7 @@ <h3>Methods</h3>
 <a href="https://api.slack.com/methods/chat.scheduledMessages.list">https://api.slack.com/methods/chat.scheduledMessages.list</a></p></div>
 </dd>
 <dt id="slack_sdk.web.async_client.AsyncWebClient.chat_startStream"><code class="name flex">
-<span>async def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str | None = None,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.async_slack_response.AsyncSlackResponse" href="async_slack_response.html#slack_sdk.web.async_slack_response.AsyncSlackResponse">AsyncSlackResponse</a></span>
+<span>async def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.async_slack_response.AsyncSlackResponse" href="async_slack_response.html#slack_sdk.web.async_slack_response.AsyncSlackResponse">AsyncSlackResponse</a></span>
 </code></dt>
 <dd>
 <details class="source">
@@ -10175,7 +10175,7 @@ <h3>Methods</h3>
     self,
     *,
     channel: str,
-    thread_ts: Optional[str] = None,
+    thread_ts: str,
     markdown_text: Optional[str] = None,
     recipient_team_id: Optional[str] = None,
     recipient_user_id: Optional[str] = None,
diff --git a/docs/reference/web/client.html b/docs/reference/web/client.html
index a6c282b4..b2d44f9e 100644
--- a/docs/reference/web/client.html
+++ b/docs/reference/web/client.html
@@ -2900,7 +2900,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
@@ -10164,7 +10164,7 @@ <h3>Methods</h3>
 <a href="https://api.slack.com/methods/chat.scheduledMessages.list">https://api.slack.com/methods/chat.scheduledMessages.list</a></p></div>
 </dd>
 <dt id="slack_sdk.web.client.WebClient.chat_startStream"><code class="name flex">
-<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str | None = None,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
+<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
 </code></dt>
 <dd>
 <details class="source">
@@ -10175,7 +10175,7 @@ <h3>Methods</h3>
     self,
     *,
     channel: str,
-    thread_ts: Optional[str] = None,
+    thread_ts: str,
     markdown_text: Optional[str] = None,
     recipient_team_id: Optional[str] = None,
     recipient_user_id: Optional[str] = None,
diff --git a/docs/reference/web/index.html b/docs/reference/web/index.html
index 1e49e8dd..17315ee9 100644
--- a/docs/reference/web/index.html
+++ b/docs/reference/web/index.html
@@ -3261,7 +3261,7 @@ <h2 id="raises">Raises</h2>
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
@@ -10525,7 +10525,7 @@ <h3>Methods</h3>
 <a href="https://api.slack.com/methods/chat.scheduledMessages.list">https://api.slack.com/methods/chat.scheduledMessages.list</a></p></div>
 </dd>
 <dt id="slack_sdk.web.WebClient.chat_startStream"><code class="name flex">
-<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str | None = None,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
+<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> <a title="slack_sdk.web.slack_response.SlackResponse" href="slack_response.html#slack_sdk.web.slack_response.SlackResponse">SlackResponse</a></span>
 </code></dt>
 <dd>
 <details class="source">
@@ -10536,7 +10536,7 @@ <h3>Methods</h3>
     self,
     *,
     channel: str,
-    thread_ts: Optional[str] = None,
+    thread_ts: str,
     markdown_text: Optional[str] = None,
     recipient_team_id: Optional[str] = None,
     recipient_user_id: Optional[str] = None,
diff --git a/docs/reference/web/legacy_client.html b/docs/reference/web/legacy_client.html
index 1cc44266..ad9ae4b9 100644
--- a/docs/reference/web/legacy_client.html
+++ b/docs/reference/web/legacy_client.html
@@ -2899,7 +2899,7 @@ <h2 class="section-title" id="header-classes">Classes</h2>
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
@@ -10163,7 +10163,7 @@ <h3>Methods</h3>
 <a href="https://api.slack.com/methods/chat.scheduledMessages.list">https://api.slack.com/methods/chat.scheduledMessages.list</a></p></div>
 </dd>
 <dt id="slack_sdk.web.legacy_client.LegacyWebClient.chat_startStream"><code class="name flex">
-<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str | None = None,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> _asyncio.Future | <a title="slack_sdk.web.legacy_slack_response.LegacySlackResponse" href="legacy_slack_response.html#slack_sdk.web.legacy_slack_response.LegacySlackResponse">LegacySlackResponse</a></span>
+<span>def <span class="ident">chat_startStream</span></span>(<span>self,<br>*,<br>channel: str,<br>thread_ts: str,<br>markdown_text: str | None = None,<br>recipient_team_id: str | None = None,<br>recipient_user_id: str | None = None,<br>unfurl_links: bool | None = None,<br>unfurl_media: bool | None = None,<br>**kwargs) ‑> _asyncio.Future | <a title="slack_sdk.web.legacy_slack_response.LegacySlackResponse" href="legacy_slack_response.html#slack_sdk.web.legacy_slack_response.LegacySlackResponse">LegacySlackResponse</a></span>
 </code></dt>
 <dd>
 <details class="source">
@@ -10174,7 +10174,7 @@ <h3>Methods</h3>
     self,
     *,
     channel: str,
-    thread_ts: Optional[str] = None,
+    thread_ts: str,
     markdown_text: Optional[str] = None,
     recipient_team_id: Optional[str] = None,
     recipient_user_id: Optional[str] = None,
diff --git a/slack_sdk/web/async_client.py b/slack_sdk/web/async_client.py
index 84a49092..5b4a474a 100644
--- a/slack_sdk/web/async_client.py
+++ b/slack_sdk/web/async_client.py
@@ -2878,7 +2878,7 @@ async def chat_startStream(
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
diff --git a/slack_sdk/web/client.py b/slack_sdk/web/client.py
index cdce5f97..fa9683b1 100644
--- a/slack_sdk/web/client.py
+++ b/slack_sdk/web/client.py
@@ -2868,7 +2868,7 @@ def chat_startStream(
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
diff --git a/slack_sdk/web/legacy_client.py b/slack_sdk/web/legacy_client.py
index 10d2c7af..55859880 100644
--- a/slack_sdk/web/legacy_client.py
+++ b/slack_sdk/web/legacy_client.py
@@ -2880,7 +2880,7 @@ def chat_startStream(
         self,
         *,
         channel: str,
-        thread_ts: Optional[str] = None,
+        thread_ts: str,
         markdown_text: Optional[str] = None,
         recipient_team_id: Optional[str] = None,
         recipient_user_id: Optional[str] = None,
diff --git a/tests/slack_sdk_async/web/test_web_client_coverage.py b/tests/slack_sdk_async/web/test_web_client_coverage.py
index d7451dd7..998c0bb3 100644
--- a/tests/slack_sdk_async/web/test_web_client_coverage.py
+++ b/tests/slack_sdk_async/web/test_web_client_coverage.py
@@ -568,10 +568,10 @@ async def run_method(self, method_name, method, async_method):
                 self.api_methods_to_call.remove(method()["method"])
                 await async_method()
             elif method_name == "chat_startStream":
-                self.api_methods_to_call.remove(method(channel="C123")["method"])
-                method(channel="C123", recipient_team_id="T123", recipient_user_id="U123")
-                await async_method(channel="C123")
-                await async_method(channel="C123", recipient_team_id="T123", recipient_user_id="U123")
+                self.api_methods_to_call.remove(method(channel="C123", thread_ts="123.123")["method"])
+                await async_method(channel="C123", thread_ts="123.123")
+                method(channel="C123", thread_ts="123.123", recipient_team_id="T123", recipient_user_id="U123")
+                await async_method(channel="C123", thread_ts="123.123", recipient_team_id="T123", recipient_user_id="U123")
             elif method_name == "chat_stopStream":
                 self.api_methods_to_call.remove(
                     method(channel="C123", ts="123.123", blocks=[{"type": "markdown", "text": "**twelve**"}])["method"]