🔢 fix: Unescape LaTeX Numbers in Artifact Content Edit (#10476)

api/server/routes/messages.js

@@ -1,4 +1,5 @@
 const express = require('express');
+const { unescapeLaTeX } = require('@librechat/api');
 const { logger } = require('@librechat/data-schemas');
 const { ContentTypes } = require('librechat-data-provider');
 const {
@@ -134,17 +135,32 @@ router.post('/artifact/:messageId', async (req, res) => {
       return res.status(400).json({ error: 'Artifact index out of bounds' });
     }
 
+    // Unescape LaTeX preprocessing done by the frontend
+    // The frontend escapes $ signs for display, but the database has unescaped versions
+    const unescapedOriginal = unescapeLaTeX(original);
+    const unescapedUpdated = unescapeLaTeX(updated);
+
     const targetArtifact = artifacts[index];
     let updatedText = null;
 
     if (targetArtifact.source === 'content') {
       const part = message.content[targetArtifact.partIndex];
-      updatedText = replaceArtifactContent(part.text, targetArtifact, original, updated);
+      updatedText = replaceArtifactContent(
+        part.text,
+        targetArtifact,
+        unescapedOriginal,
+        unescapedUpdated,
+      );
       if (updatedText) {
         part.text = updatedText;
       }
     } else {
-      updatedText = replaceArtifactContent(message.text, targetArtifact, original, updated);
+      updatedText = replaceArtifactContent(
+        message.text,
+        targetArtifact,
+        unescapedOriginal,
+        unescapedUpdated,
+      );
       if (updatedText) {
         message.text = updatedText;
       }

packages/api/src/utils/index.ts

@@ -7,6 +7,7 @@ export * from './events';
 export * from './files';
 export * from './generators';
 export * from './key';
+export * from './latex';
 export * from './llm';
 export * from './math';
 export * from './openid';

packages/api/src/utils/latex.spec.ts

@@ -0,0 +1,122 @@
+import { unescapeLaTeX } from './latex';
+
+describe('unescapeLaTeX', () => {
+  describe('currency dollar signs', () => {
+    it('should unescape single backslash dollar signs', () => {
+      const input = 'Price: \\$14';
+      const expected = 'Price: $14';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+
+    it('should unescape double backslash dollar signs', () => {
+      const input = 'Price: \\\\$14';
+      const expected = 'Price: $14';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+
+    it('should unescape multiple currency values', () => {
+      const input = '**Crispy Calamari** - *\\\\$14*\n**Truffle Fries** - *\\\\$12*';
+      const expected = '**Crispy Calamari** - *$14*\n**Truffle Fries** - *$12*';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+
+    it('should handle currency with commas and decimals', () => {
+      const input = 'Total: \\\\$1,234.56';
+      const expected = 'Total: $1,234.56';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+  });
+
+  describe('mhchem notation', () => {
+    it('should unescape mhchem ce notation', () => {
+      const input = '$$\\\\ce{H2O}$$';
+      const expected = '$\\ce{H2O}$';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+
+    it('should unescape mhchem pu notation', () => {
+      const input = '$$\\\\pu{123 kJ/mol}$$';
+      const expected = '$\\pu{123 kJ/mol}$';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+
+    it('should handle multiple mhchem expressions', () => {
+      const input = '$$\\\\ce{H2O}$$ and $$\\\\ce{CO2}$$';
+      const expected = '$\\ce{H2O}$ and $\\ce{CO2}$';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+  });
+
+  describe('edge cases', () => {
+    it('should handle empty string', () => {
+      expect(unescapeLaTeX('')).toBe('');
+    });
+
+    it('should handle null', () => {
+      expect(unescapeLaTeX(null)).toBe(null);
+    });
+
+    it('should handle undefined', () => {
+      expect(unescapeLaTeX(undefined)).toBe(undefined);
+    });
+
+    it('should handle string with no dollar signs', () => {
+      const input = 'Hello world';
+      expect(unescapeLaTeX(input)).toBe(input);
+    });
+
+    it('should handle mixed escaped and unescaped content', () => {
+      const input = 'Price \\\\$14 and some text';
+      const expected = 'Price $14 and some text';
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+  });
+
+  describe('real-world example from bug report', () => {
+    it('should correctly unescape restaurant menu content', () => {
+      const input = `# The Golden Spoon
+## *Contemporary American Cuisine*
+
+---
+
+### STARTERS
+
+**Crispy Calamari** - *\\\\$14*  
+Lightly fried, served with marinara & lemon aioli
+
+**Truffle Fries** - *\\\\$12*  
+Hand-cut fries, parmesan, truffle oil, fresh herbs
+
+**Burrata & Heirloom Tomatoes** - *\\\\$16*  
+Fresh burrata, basil pesto, balsamic reduction, grilled sourdough
+
+**Thai Chicken Lettuce Wraps** - *\\\\$13*  
+Spicy ground chicken, water chestnuts, ginger-soy glaze
+
+**Soup of the Day** - *\\\\$9`;
+
+      const expected = `# The Golden Spoon
+## *Contemporary American Cuisine*
+
+---
+
+### STARTERS
+
+**Crispy Calamari** - *$14*  
+Lightly fried, served with marinara & lemon aioli
+
+**Truffle Fries** - *$12*  
+Hand-cut fries, parmesan, truffle oil, fresh herbs
+
+**Burrata & Heirloom Tomatoes** - *$16*  
+Fresh burrata, basil pesto, balsamic reduction, grilled sourdough
+
+**Thai Chicken Lettuce Wraps** - *$13*  
+Spicy ground chicken, water chestnuts, ginger-soy glaze
+
+**Soup of the Day** - *$9`;
+
+      expect(unescapeLaTeX(input)).toBe(expected);
+    });
+  });
+});

packages/api/src/utils/latex.ts

@@ -0,0 +1,27 @@
+/**
+ * Unescapes LaTeX preprocessing done by the frontend preprocessLaTeX function.
+ * This reverses the escaping of currency dollar signs and other LaTeX transformations.
+ *
+ * The frontend escapes dollar signs for proper LaTeX rendering (e.g., $14 → \\$14),
+ * but the database stores the original unescaped versions. This function reverses
+ * that transformation to match database content.
+ *
+ * @param text - The escaped text from the frontend
+ * @returns The unescaped text matching the database format
+ */
+export function unescapeLaTeX(text: string | null | undefined): string | null | undefined {
+  if (!text || typeof text !== 'string') {
+    return text;
+  }
+
+  // Unescape currency dollar signs (\\$ or \$ → $)
+  // This is the main transformation done by preprocessLaTeX for currency
+  let result = text.replace(/\\\\?\$/g, '$');
+
+  // Unescape mhchem notation if present
+  // Convert $$\\ce{...}$$ back to $\ce{...}$
+  result = result.replace(/\$\$\\\\ce\{([^}]*)\}\$\$/g, '$\\ce{$1}$');
+  result = result.replace(/\$\$\\\\pu\{([^}]*)\}\$\$/g, '$\\pu{$1}$');
+
+  return result;
+}