🔗 feat: Agent Chain (Mixture-of-Agents) (#6374)

* wip: first pass, dropdown for selecting sequential agents

* refactor: Improve agent selection logic and enhance performance in SequentialAgents component

* wip: seq. agents working ideas

* wip: sequential agents style change

* refactor: move agent form options/submission outside of AgentConfig

* refactor: prevent repeating code

* refactor: simplify current agent display in SequentialAgents component

* feat: persist  form value handling in AgentSelect component for agent_ids

* feat: first pass, sequential agnets agent update

* feat: enhance message display with agent updates and empty text handling

* chore: update Icon component to use EModelEndpoint for agent endpoints

* feat: update content type checks in BaseClient to use constants for better readability

* feat: adjust max context tokens calculation to use 90% of the model's max tokens

* feat: first pass, agent run message pruning

* chore: increase max listeners for abort controller to prevent memory leaks

* feat: enhance runAgent function to include current index count map for improved token tracking

* chore: update @librechat/agents dependency to version 2.2.5

* feat: update icons and style of SequentialAgents component for improved UI consistency

* feat: add AdvancedButton and AdvancedPanel components for enhanced agent settings navigation, update styling for agent form

* chore: adjust minimum height of AdvancedPanel component for better layout consistency

* chore: update @librechat/agents dependency to version 2.2.6

* feat: enhance message formatting by incorporating tool set into agent message processing, in order to allow better mix/matching of agents (as tool calls for tools not found in set will be stringified)

* refactor: reorder components in AgentConfig for improved readability and maintainability

* refactor: enhance layout of AgentUpdate component for improved visual structure

* feat: add DeepSeek provider to Bedrock settings and schemas

* feat: enhance link styling in mobile.css for better visibility and accessibility

* fix: update banner model import in update banner script; export Banner model

* refactor: `duplicateAgentHandler` to include tool_resources only for OCR context files

* feat: add 'qwen-vl' to visionModels for enhanced model support

* fix: change image format from JPEG to PNG in DALLE3 response

* feat: reorganize Advanced components and add localizations

* refactor: simplify JSX structure in AgentChain component to defer container styling to parent

* feat: add FormInput component for reusable input handling

* feat: make agent recursion limit configurable from builder

* feat: add support for agent capabilities chain in AdvancedPanel and update data-provider version

* feat: add maxRecursionLimit configuration for agents and update related documentation

* fix: update CONFIG_VERSION to 1.2.3 in data provider configuration

* feat: replace recursion limit input with MaxAgentSteps component and enhance input handling

* feat: enhance AgentChain component with hover card for additional information and update related labels

* fix: pass request and response objects to `createActionTool` when using assistant actions to prevent auth error

* feat: update AgentChain component layout to include agent count display

* feat: increase default max listeners and implement capability check function for agent chain

* fix: update link styles in mobile.css for better visibility in dark mode

* chore: temp. remove agents package while bumping shared packages

* chore: update @langchain/google-genai package to version 0.1.11

* chore: update @langchain/google-vertexai package to version 0.2.2

* chore: add @librechat/agents package at version 2.2.8

* feat: add deepseek.r1 model with token rate and context values for bedrock

client/src/hooks/SSE/useStepHandler.ts

@@ -23,6 +23,7 @@ type TStepEvent = {
   event: string;
   data:
     | Agents.MessageDeltaEvent
+    | Agents.AgentUpdate
     | Agents.RunStep
     | Agents.ToolEndEvent
     | {
@@ -87,6 +88,17 @@ export default function useStepHandler({
       if (contentPart.tool_call_ids != null) {
         update.tool_call_ids = contentPart.tool_call_ids;
       }
+      updatedContent[index] = update;
+    } else if (
+      contentType.startsWith(ContentTypes.AGENT_UPDATE) &&
+      ContentTypes.AGENT_UPDATE in contentPart &&
+      contentPart.agent_update
+    ) {
+      const update: Agents.AgentUpdate = {
+        type: ContentTypes.AGENT_UPDATE,
+        agent_update: contentPart.agent_update,
+      };
+
       updatedContent[index] = update;
     } else if (
       contentType.startsWith(ContentTypes.THINK) &&
@@ -191,29 +203,20 @@ export default function useStepHandler({
           });
         }
       } else if (event === 'on_agent_update') {
-        const { runId, message } = data as { runId?: string; message: string };
-        const responseMessageId = runId ?? '';
+        const { agent_update } = data as Agents.AgentUpdate;
+        const responseMessageId = agent_update.runId || '';
         if (!responseMessageId) {
           console.warn('No message id found in agent update event');
           return;
         }
 
-        const responseMessage = messages[messages.length - 1] as TMessage;
-
-        const response = {
-          ...responseMessage,
-          parentMessageId: userMessage.messageId,
-          conversationId: userMessage.conversationId,
-          messageId: responseMessageId,
-          content: [
-            {
-              type: ContentTypes.TEXT,
-              text: message,
-            },
-          ],
-        } as TMessage;
-
-        setMessages([...messages.slice(0, -1), response]);
+        const response = messageMap.current.get(responseMessageId);
+        if (response) {
+          const updatedResponse = updateContent(response, agent_update.index, data);
+          messageMap.current.set(responseMessageId, updatedResponse);
+          const currentMessages = getMessages() || [];
+          setMessages([...currentMessages.slice(0, -1), updatedResponse]);
+        }
       } else if (event === 'on_message_delta') {
         const messageDelta = data as Agents.MessageDeltaEvent;
         const runStep = stepMap.current.get(messageDelta.id);