docs[patch]: Add custom callback event guide to index page

docs/core_docs/.gitignore

@@ -155,6 +155,10 @@ docs/how_to/document_loader_html.md
 docs/how_to/document_loader_html.mdx
 docs/how_to/custom_tools.md
 docs/how_to/custom_tools.mdx
+docs/how_to/custom_llm.md
+docs/how_to/custom_llm.mdx
+docs/how_to/custom_chat.md
+docs/how_to/custom_chat.mdx
 docs/how_to/custom_callbacks.md
 docs/how_to/custom_callbacks.mdx
 docs/how_to/code_splitter.md
@@ -171,6 +175,8 @@ docs/how_to/character_text_splitter.md
 docs/how_to/character_text_splitter.mdx
 docs/how_to/callbacks_runtime.md
 docs/how_to/callbacks_runtime.mdx
+docs/how_to/callbacks_custom_events.md
+docs/how_to/callbacks_custom_events.mdx
 docs/how_to/callbacks_constructor.md
 docs/how_to/callbacks_constructor.mdx
 docs/how_to/callbacks_backgrounding.md

docs/core_docs/docs/concepts.mdx

@@ -765,7 +765,8 @@ for await (const event of eventStream) {
 
 You can roughly think of it as an iterator over callback events (though the format differs) - and you can use it on almost all LangChain components!
 
-See [this guide](/docs/how_to/streaming/#using-stream-events) for more detailed information on how to use `.streamEvents()`.
+See [this guide](/docs/how_to/streaming/#using-stream-events) for more detailed information on how to use `.streamEvents()`,
+or [this guide](/docs/how_to/callbacks_custom_events) for how to stream custom events from within a chain.
 
 #### Tokens
 

docs/core_docs/docs/how_to/callbacks_custom_events.ipynb

@@ -42,11 +42,13 @@
     "\n",
     "We can use the `dispatchCustomEvent` API to emit custom events from this method. \n",
     "\n",
+    "```{=mdx}\n",
     ":::caution Compatibility\n",
     "Dispatching custom callback events requires `@langchain/core>=0.2.16`. See [this guide](/docs/how_to/installation/#installing-integration-packages) for some considerations to take when upgrading `@langchain/core`.\n",
     "\n",
     "The default entrypoint below triggers an import and initialization of [`async_hooks`](https://nodejs.org/api/async_hooks.html) to enable automatic `RunnableConfig` passing, which is not supported in all environments. If you see import issues, you must import from `@langchain/callbacks/dispatch/web` and propagate the `RunnableConfig` object manually (see example below).\n",
-    ":::"
+    ":::\n",
+    "```"
    ]
   },
   {

docs/core_docs/docs/how_to/index.mdx

@@ -184,6 +184,7 @@ For in depth how-to guides for agents, please check out [LangGraph](https://lang
 - [How to: pass callbacks into a module constructor](/docs/how_to/callbacks_constructor)
 - [How to: create custom callback handlers](/docs/how_to/custom_callbacks)
 - [How to: make callbacks run in the background](/docs/how_to/callbacks_backgrounding)
+- [How to: dispatch custom callback events](/docs/how_to/callbacks_custom_events)
 
 ### Custom
 
@@ -193,8 +194,9 @@ All of LangChain components can easily be extended to support your own versions.
 - [How to: create a custom LLM class](/docs/how_to/custom_llm)
 - [How to: write a custom retriever class](/docs/how_to/custom_retriever)
 - [How to: write a custom document loader](/docs/how_to/document_loader_custom)
-- [How to: define a custom tool](/docs/how_to/custom_tools)
 - [How to: create custom callback handlers](/docs/how_to/custom_callbacks)
+- [How to: define a custom tool](/docs/how_to/custom_tools)
+- [How to: dispatch custom callback events](/docs/how_to/callbacks_custom_events)
 
 ### Generative UI
 

docs/core_docs/docs/how_to/streaming.ipynb

@@ -2028,13 +2028,22 @@
     "\n",
     "Chat model chunk: {"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Related\n",
+    "\n",
+    "- [Dispatching custom events](/docs/how_to/callbacks_custom_events)"
+   ]
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "TypeScript",
+   "display_name": "Deno",
    "language": "typescript",
-   "name": "tslab"
+   "name": "deno"
   },
   "language_info": {
    "codemirror_mode": {