🚀 feat: Artifact Editing & Downloads (danny-avila#5428)

* refactor: expand container

* chore: bump @codesandbox/sandpack-react to latest

* WIP: first pass, show editor

* feat: implement ArtifactCodeEditor and ArtifactTabs components for enhanced artifact management

* refactor: fileKey

* refactor: auto scrolling code editor and add messageId to artifact

* feat: first pass, editing artifact

* feat: first pass, robust artifact replacement

* fix: robust artifact replacement & re-render when expected

* feat: Download Artifacts

* refactor: improve artifact editing UX

* fix: layout shift of new download button

* fix: enhance missing output checks and logging in StreamRunManager

Author: danny-avila

api/server/routes/messages.js

@@ -1,13 +1,83 @@
 const express = require('express');
 const { ContentTypes } = require('librechat-data-provider');
-const { saveConvo, saveMessage, getMessages, updateMessage, deleteMessages } = require('~/models');
+const {
+  saveConvo,
+  saveMessage,
+  getMessage,
+  getMessages,
+  updateMessage,
+  deleteMessages,
+} = require('~/models');
+const { findAllArtifacts, replaceArtifactContent } = require('~/server/services/Artifacts/update');
 const { requireJwtAuth, validateMessageReq } = require('~/server/middleware');
 const { countTokens } = require('~/server/utils');
 const { logger } = require('~/config');
 
 const router = express.Router();
 router.use(requireJwtAuth);
 
+router.post('/artifact/:messageId', async (req, res) => {
+  try {
+    const { messageId } = req.params;
+    const { index, original, updated } = req.body;
+
+    if (typeof index !== 'number' || index < 0 || !original || !updated) {
+      return res.status(400).json({ error: 'Invalid request parameters' });
+    }
+
+    const message = await getMessage({ user: req.user.id, messageId });
+    if (!message) {
+      return res.status(404).json({ error: 'Message not found' });
+    }
+
+    const artifacts = findAllArtifacts(message);
+    if (index >= artifacts.length) {
+      return res.status(400).json({ error: 'Artifact index out of bounds' });
+    }
+
+    const targetArtifact = artifacts[index];
+    let updatedText = null;
+
+    if (targetArtifact.source === 'content') {
+      const part = message.content[targetArtifact.partIndex];
+      updatedText = replaceArtifactContent(part.text, targetArtifact, original, updated);
+      if (updatedText) {
+        part.text = updatedText;
+      }
+    } else {
+      updatedText = replaceArtifactContent(message.text, targetArtifact, original, updated);
+      if (updatedText) {
+        message.text = updatedText;
+      }
+    }
+
+    if (!updatedText) {
+      return res.status(400).json({ error: 'Original content not found in target artifact' });
+    }
+
+    const savedMessage = await saveMessage(
+      req,
+      {
+        messageId,
+        conversationId: message.conversationId,
+        text: message.text,
+        content: message.content,
+        user: req.user.id,
+      },
+      { context: 'POST /api/messages/artifact/:messageId' },
+    );
+
+    res.status(200).json({
+      conversationId: savedMessage.conversationId,
+      content: savedMessage.content,
+      text: savedMessage.text,
+    });
+  } catch (error) {
+    logger.error('Error editing artifact:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
 /* Note: It's necessary to add `validateMessageReq` within route definition for correct params */
 router.get('/:conversationId', validateMessageReq, async (req, res) => {
   try {

api/server/services/Artifacts/update.js

@@ -0,0 +1,81 @@
+const ARTIFACT_START = ':::artifact';
+const ARTIFACT_END = ':::';
+
+/**
+ * Find all artifact boundaries in the message
+ * @param {TMessage} message
+ * @returns {Array<{start: number, end: number, source: 'content'|'text', partIndex?: number}>}
+ */
+const findAllArtifacts = (message) => {
+  const artifacts = [];
+
+  // Check content parts first
+  if (message.content?.length) {
+    message.content.forEach((part, partIndex) => {
+      if (part.type === 'text' && typeof part.text === 'string') {
+        let currentIndex = 0;
+        let start = part.text.indexOf(ARTIFACT_START, currentIndex);
+
+        while (start !== -1) {
+          const end = part.text.indexOf(ARTIFACT_END, start + ARTIFACT_START.length);
+          artifacts.push({
+            start,
+            end: end !== -1 ? end + ARTIFACT_END.length : part.text.length,
+            source: 'content',
+            partIndex,
+            text: part.text,
+          });
+
+          currentIndex = end !== -1 ? end + ARTIFACT_END.length : part.text.length;
+          start = part.text.indexOf(ARTIFACT_START, currentIndex);
+        }
+      }
+    });
+  }
+
+  // Check message.text if no content parts
+  if (!artifacts.length && message.text) {
+    let currentIndex = 0;
+    let start = message.text.indexOf(ARTIFACT_START, currentIndex);
+
+    while (start !== -1) {
+      const end = message.text.indexOf(ARTIFACT_END, start + ARTIFACT_START.length);
+      artifacts.push({
+        start,
+        end: end !== -1 ? end + ARTIFACT_END.length : message.text.length,
+        source: 'text',
+        text: message.text,
+      });
+
+      currentIndex = end !== -1 ? end + ARTIFACT_END.length : message.text.length;
+      start = message.text.indexOf(ARTIFACT_START, currentIndex);
+    }
+  }
+
+  return artifacts;
+};
+
+const replaceArtifactContent = (originalText, artifact, original, updated) => {
+  const artifactContent = artifact.text.substring(artifact.start, artifact.end);
+  const relativeIndex = artifactContent.indexOf(original);
+
+  if (relativeIndex === -1) {
+    return null;
+  }
+
+  const absoluteIndex = artifact.start + relativeIndex;
+  const endText = originalText.substring(absoluteIndex + original.length);
+  const hasTrailingNewline = endText.startsWith('\n');
+
+  const updatedText =
+    originalText.substring(0, absoluteIndex) + updated + (hasTrailingNewline ? '' : '\n') + endText;
+
+  return updatedText.replace(/\n+(?=```\n:::)/g, '\n');
+};
+
+module.exports = {
+  ARTIFACT_START,
+  ARTIFACT_END,
+  findAllArtifacts,
+  replaceArtifactContent,
+};