🪙 fix: Count quote tokens on message edit so context stays accurate

The message-edit route recomputed a user message's tokenCount from the edited
`text` alone, ignoring its persisted `quotes`. But the send path re-prepends
those quotes into the prompt on every turn (mergeQuotedText), so after editing a
quoted message the stored tokenCount under-reported by the whole quote block,
skewing the context gauge and any other tokenCount consumer.

The full-recount path now fetches the message's quotes and counts the merged
text+quotes via a new `mergeQuotedTextForCount` helper in packages/api (mirrors
the send path), so the stored count stays authoritative. The incremental
content-part path is left as-is: it deltas only the edited part and preserves the
rest of the count (incl. the quote contribution), and applies to content-array
messages rather than text+quotes user turns.

Deferred follow-up from #13953.

api/server/routes/messages.js

@@ -7,6 +7,7 @@ const {
   countTokens,
   sendFeedbackScore,
   traceIdForMessage,
+  mergeQuotedTextForCount,
 } = require('@librechat/api');
 const { findAllArtifacts, replaceArtifactContent } = require('~/server/services/Artifacts/update');
 const { requireJwtAuth, validateMessageReq } = require('~/server/middleware');
@@ -329,7 +330,22 @@ router.put('/:conversationId/:messageId', validateMessageReq, async (req, res) =
     const { text, index, model } = req.body;
 
     if (index === undefined) {
-      const tokenCount = await countTokens(text, model);
+      /** A user turn's persisted `quotes` are re-prepended into the prompt on
+       *  every send, but this edit only changes `text`. Count the merged
+       *  text+quotes so the stored `tokenCount` stays authoritative (matching the
+       *  send path); a plain text-only count under-reports by the quote block. */
+      const existing = (
+        await db.getMessages(
+          { conversationId, messageId, user: req.user.id },
+          'quotes isCreatedByUser',
+        )
+      )?.[0];
+      const textToCount = mergeQuotedTextForCount(
+        text,
+        existing?.quotes,
+        existing?.isCreatedByUser === true,
+      );
+      const tokenCount = await countTokens(textToCount, model);
       const result = await db.updateMessage(req?.user?.id, { messageId, text, tokenCount });
       return res.status(200).json(result);
     }

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

@@ -0,0 +1,36 @@
+import { mergeQuotedTextForCount, QUOTE_MAX_COUNT } from './quotes';
+
+describe('mergeQuotedTextForCount', () => {
+  it('returns text unchanged for non-user messages', () => {
+    expect(mergeQuotedTextForCount('hi', ['quote'], false)).toBe('hi');
+  });
+
+  it('returns text unchanged when there are no usable quotes', () => {
+    expect(mergeQuotedTextForCount('hi', undefined, true)).toBe('hi');
+    expect(mergeQuotedTextForCount('hi', [], true)).toBe('hi');
+    expect(mergeQuotedTextForCount('hi', ['', '   '], true)).toBe('hi');
+    expect(mergeQuotedTextForCount('hi', 'not-an-array', true)).toBe('hi');
+  });
+
+  it('prepends merged quotes for a user message with quotes', () => {
+    const out = mergeQuotedTextForCount('my question', ['excerpt one'], true);
+    expect(out).toBe('> excerpt one\n\nmy question');
+    /** Longer than the bare text, so counting `out` exceeds counting text alone —
+     *  the under-report this fix addresses. */
+    expect(out.length).toBeGreaterThan('my question'.length);
+  });
+
+  it('normalizes quotes (drops non-strings and empties, trims) before merging', () => {
+    const out = mergeQuotedTextForCount('q', ['keep', 42, '', '  trim  '], true);
+    expect(out).toContain('> keep');
+    expect(out).toContain('> trim');
+    expect(out).not.toContain('42');
+  });
+
+  it('caps the number of merged excerpts at QUOTE_MAX_COUNT', () => {
+    const many = Array.from({ length: QUOTE_MAX_COUNT + 5 }, (_, i) => `q${i}`);
+    const out = mergeQuotedTextForCount('body', many, true);
+    const quoteBlocks = out.split('\n\n').filter((block) => block.startsWith('>'));
+    expect(quoteBlocks).toHaveLength(QUOTE_MAX_COUNT);
+  });
+});

packages/api/src/utils/quotes.ts

@@ -67,3 +67,22 @@ export function mergeQuotedText(text: string, quotes: string[]): string {
   const body = text ?? '';
   return body.length > 0 ? `${block}\n\n${body}` : block;
 }
+
+/**
+ * Resolves the prompt text to tokenize for a (possibly quoted) user turn,
+ * mirroring the send path: a user message's persisted `quotes` are prepended
+ * into the prompt on every turn, so an edit that only changes `text` must count
+ * the merged text+quotes to keep the stored `tokenCount` authoritative. Returns
+ * `text` unchanged for non-user messages or when there are no usable quotes.
+ */
+export function mergeQuotedTextForCount(
+  text: string,
+  rawQuotes: unknown,
+  isCreatedByUser: boolean,
+): string {
+  if (!isCreatedByUser) {
+    return text;
+  }
+  const quotes = getReferencedQuotes(rawQuotes);
+  return quotes ? mergeQuotedText(text, quotes) : text;
+}