Feature/sse (#3125)

* Base changes for ServerSide Events (instead of socket.io)

* lint fixes

* adding of interface and separate methods for streaming events

* lint

* first draft, handles both internal and external prediction end points.

* lint fixes

* additional internal end point for streaming and associated changes

* return streamresponse as true to build agent flow

* 1) JSON formatting for internal events
2) other fixes

* 1) convert internal event to metadata to maintain consistency with external response

* fix action and metadata streaming

* fix for error when agent flow is aborted

* prevent subflows from streaming and other code cleanup

* prevent streaming from enclosed tools

* add fix for preventing chaintool streaming

* update lock file

* add open when hidden to sse

* Streaming errors

* Streaming errors

* add fix for showing error message

---------

Co-authored-by: Henry <hzj94@hotmail.com>

packages/components/nodes/tools/ChatflowTool/ChatflowTool.ts

@@ -7,6 +7,7 @@ import { StructuredTool } from '@langchain/core/tools'
 import { ICommonObject, IDatabaseEntity, INode, INodeData, INodeOptionsValue, INodeParams } from '../../../src/Interface'
 import { availableDependencies, defaultAllowBuiltInDep, getCredentialData, getCredentialParam } from '../../../src/utils'
 import { v4 as uuidv4 } from 'uuid'
+import { CustomChainHandler } from '../../../src'
 
 class ChatflowTool_Tools implements INode {
     label: string
@@ -248,6 +249,15 @@ class ChatflowTool extends StructuredTool {
         } catch (e) {
             throw new Error(`Received tool input did not match expected schema: ${JSON.stringify(arg)}`)
         }
+        // iterate over the callbacks and the sse streamer
+        if (config.callbacks instanceof CallbackManager) {
+            const callbacks = config.callbacks.handlers
+            for (let i = 0; i < callbacks.length; i += 1) {
+                if (callbacks[i] instanceof CustomChainHandler) {
+                    ;(callbacks[i] as any).sseStreamer = undefined
+                }
+            }
+        }
         const callbackManager_ = await CallbackManager.configure(
             config.callbacks,
             this.callbacks,