⏸ refactor: Improve UX for Parallel Streams (Multi-Convo) (#11096)

* 🌊 feat: Implement multi-conversation feature with added conversation context and payload adjustments

* refactor: Replace isSubmittingFamily with isSubmitting across message components for consistency

* feat: Add loadAddedAgent and processAddedConvo for multi-conversation agent execution

* refactor: Update ContentRender usage to conditionally render PlaceholderRow based on isLast and isSubmitting

* WIP: first pass, sibling index

* feat: Enhance multi-conversation support with agent tracking and display improvements

* refactor: Introduce isEphemeralAgentId utility and update related logic for agent handling

* refactor: Implement createDualMessageContent utility for sibling message display and enhance useStepHandler for added conversations

* refactor: duplicate tools for added agent if ephemeral and primary agent is also ephemeral

* chore: remove deprecated multimessage rendering

* refactor: enhance dual message content creation and agent handling for parallel rendering

* refactor: streamline message rendering and submission handling by removing unused state and optimizing conditional logic

* refactor: adjust content handling in parallel mode to utilize existing content for improved agent display

* refactor: update @librechat/agents dependency to version 3.0.53

* refactor: update @langchain/core and @librechat/agents dependencies to latest versions

* refactor: remove deprecated @langchain/core dependency from package.json

* chore: remove unused SearchToolConfig and GetSourcesParams types from web.ts

* refactor: remove unused message properties from Message component

* refactor: enhance parallel content handling with groupId support in ContentParts and useStepHandler

* refactor: implement parallel content styling in Message, MessageRender, and ContentRender components. use explicit model name

* refactor: improve agent ID handling in createDualMessageContent for dual message display

* refactor: simplify title generation in AddedConvo by removing unused sender and preset logic

* refactor: replace string interpolation with cn utility for className in HoverButtons component

* refactor: enhance agent ID handling by adding suffix management for parallel agents and updating related components

* refactor: enhance column ordering in ContentParts by sorting agents with suffix management

* refactor: update @librechat/agents dependency to version 3.0.55

* feat: implement parallel content rendering with metadata support

- Added `ParallelContentRenderer` and `ParallelColumns` components for rendering messages in parallel based on groupId and agentId.
- Introduced `contentMetadataMap` to store metadata for each content part, allowing efficient parallel content detection.
- Updated `Message` and `ContentRender` components to utilize the new metadata structure for rendering.
- Modified `useStepHandler` to manage content indices and metadata during message processing.
- Enhanced `IJobStore` interface and its implementations to support storing and retrieving content metadata.
- Updated data schemas to include `contentMetadataMap` for messages, enabling multi-agent and parallel execution scenarios.

* refactor: update @librechat/agents dependency to version 3.0.56

* refactor: remove unused EPHEMERAL_AGENT_ID constant and simplify agent ID check

* refactor: enhance multi-agent message processing and primary agent determination

* refactor: implement branch message functionality for parallel responses

* refactor: integrate added conversation retrieval into message editing and regeneration processes

* refactor: remove unused isCard and isMultiMessage props from MessageRender and ContentRender components

* refactor: update @librechat/agents dependency to version 3.0.60

* refactor: replace usage of EPHEMERAL_AGENT_ID constant with isEphemeralAgentId function for improved clarity and consistency

* refactor: standardize agent ID format in tests for consistency

* chore: move addedConvo property to the correct position in payload construction

* refactor: rename agent_id values in loadAgent tests for clarity

* chore: reorder props in ContentParts component for improved readability

* refactor: rename variable 'content' to 'result' for clarity in RedisJobStore tests

* refactor: streamline useMessageActions by removing duplicate handleFeedback assignment

* chore: revert placeholder rendering logic MessageRender and ContentRender components to original

* refactor: implement useContentMetadata hook for optimized content metadata handling

* refactor: remove contentMetadataMap and related logic from the codebase and revert back to agentId/groupId in content parts

- Eliminated contentMetadataMap from various components and services, simplifying the handling of message content.
- Updated functions to directly access agentId and groupId from content parts instead of relying on a separate metadata map.
- Adjusted related hooks and components to reflect the removal of contentMetadataMap, ensuring consistent handling of message content.
- Updated tests and documentation to align with the new structure of message content handling.

* refactor: remove logging from groupParallelContent function to clean up output

* refactor: remove model parameter from TBranchMessageRequest type for simplification

* refactor: enhance branch message creation by stripping metadata for standalone content

* chore: streamline branch message creation by simplifying content filtering and removing unnecessary metadata checks

* refactor: include attachments in branch message creation for improved content handling

* refactor: streamline agent content processing by consolidating primary agent identification and filtering logic

* refactor: simplify multi-agent message processing by creating a dedicated mapping method and enhancing content filtering

* refactor: remove unused parameter from loadEphemeralAgent function for cleaner code

* refactor: update groupId handling in metadata to only set when provided by the server

api/server/routes/messages.js

@@ -1,4 +1,5 @@
 const express = require('express');
+const { v4: uuidv4 } = require('uuid');
 const { logger } = require('@librechat/data-schemas');
 const { ContentTypes } = require('librechat-data-provider');
 const { unescapeLaTeX, countTokens } = require('@librechat/api');
@@ -111,6 +112,91 @@ router.get('/', async (req, res) => {
   }
 });
 
+/**
+ * Creates a new branch message from a specific agent's content within a parallel response message.
+ * Filters the original message's content to only include parts attributed to the specified agentId.
+ * Only available for non-user messages with content attributions.
+ *
+ * @route POST /branch
+ * @param {string} req.body.messageId - The ID of the source message
+ * @param {string} req.body.agentId - The agentId to filter content by
+ * @returns {TMessage} The newly created branch message
+ */
+router.post('/branch', async (req, res) => {
+  try {
+    const { messageId, agentId } = req.body;
+    const userId = req.user.id;
+
+    if (!messageId || !agentId) {
+      return res.status(400).json({ error: 'messageId and agentId are required' });
+    }
+
+    const sourceMessage = await getMessage({ user: userId, messageId });
+    if (!sourceMessage) {
+      return res.status(404).json({ error: 'Source message not found' });
+    }
+
+    if (sourceMessage.isCreatedByUser) {
+      return res.status(400).json({ error: 'Cannot branch from user messages' });
+    }
+
+    if (!Array.isArray(sourceMessage.content)) {
+      return res.status(400).json({ error: 'Message does not have content' });
+    }
+
+    const hasAgentMetadata = sourceMessage.content.some((part) => part?.agentId);
+    if (!hasAgentMetadata) {
+      return res
+        .status(400)
+        .json({ error: 'Message does not have parallel content with attributions' });
+    }
+
+    /** @type {Array<import('librechat-data-provider').TMessageContentParts>} */
+    const filteredContent = [];
+    for (const part of sourceMessage.content) {
+      if (part?.agentId === agentId) {
+        const { agentId: _a, groupId: _g, ...cleanPart } = part;
+        filteredContent.push(cleanPart);
+      }
+    }
+
+    if (filteredContent.length === 0) {
+      return res.status(400).json({ error: 'No content found for the specified agentId' });
+    }
+
+    const newMessageId = uuidv4();
+    /** @type {import('librechat-data-provider').TMessage} */
+    const newMessage = {
+      messageId: newMessageId,
+      conversationId: sourceMessage.conversationId,
+      parentMessageId: sourceMessage.parentMessageId,
+      attachments: sourceMessage.attachments,
+      isCreatedByUser: false,
+      model: sourceMessage.model,
+      endpoint: sourceMessage.endpoint,
+      sender: sourceMessage.sender,
+      iconURL: sourceMessage.iconURL,
+      content: filteredContent,
+      unfinished: false,
+      error: false,
+      user: userId,
+    };
+
+    const savedMessage = await saveMessage(req, newMessage, {
+      context: 'POST /api/messages/branch',
+    });
+
+    if (!savedMessage) {
+      return res.status(500).json({ error: 'Failed to save branch message' });
+    }
+
+    res.status(201).json(savedMessage);
+  } catch (error) {
+    logger.error('Error creating branch message:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
 router.post('/artifact/:messageId', async (req, res) => {
   try {
     const { messageId } = req.params;