📁 feat: Send Attachments Directly to Provider (OpenAI) (#9098)

* refactor: change references from direct upload to direct attach to better reflect functionality

since we are just using base64 encoding strategy now rather than Files/File API for sending our attachments directly to the provider, the upload nomenclature no longer makes sense. direct_attach better describes the different methods of sending attachments to providers anyways even if we later introduce direct upload support

* feat: add upload to provider option for openai (and agent) ui

* chore: move anthropic pdf validator over to packages/api

* feat: simple pdf validation according to openai docs

* feat: add provider agnostic validatePdf logic to start handling multiple endpoints

* feat: add handling for openai specific documentPart formatting

* refactor: move require statement to proper place at top of file

* chore: add in openAI endpoint for the rest of the document handling logic

* feat: add direct attach support for azureOpenAI endpoint and agents

* feat: add pdf validation for azureOpenAI endpoint

* refactor: unify all the endpoint checks with isDocumentSupportedEndpoint

* refactor: consolidate Upload to Provider vs Upload image logic for clarity

* refactor: remove anthropic from anthropic_multimodal fileType since we support multiple providers now

packages/api/src/files/index.ts

@@ -2,3 +2,4 @@ export * from './mistral/crud';
 export * from './audio';
 export * from './text';
 export * from './parse';
+export * from './validation';

packages/api/src/files/validation.ts

@@ -0,0 +1,98 @@
+import { anthropicPdfSizeLimit, EModelEndpoint } from 'librechat-data-provider';
+
+export interface PDFValidationResult {
+  isValid: boolean;
+  error?: string;
+}
+
+export async function validatePdf(
+  pdfBuffer: Buffer,
+  fileSize: number,
+  endpoint: EModelEndpoint,
+): Promise<PDFValidationResult> {
+  if (endpoint === EModelEndpoint.anthropic) {
+    return validateAnthropicPdf(pdfBuffer, fileSize);
+  }
+
+  if (endpoint === EModelEndpoint.openAI || endpoint === EModelEndpoint.azureOpenAI) {
+    return validateOpenAIPdf(fileSize);
+  }
+
+  return { isValid: true };
+}
+
+/**
+ * Validates if a PDF meets Anthropic's requirements
+ * @param pdfBuffer - The PDF file as a buffer
+ * @param fileSize - The file size in bytes
+ * @returns Promise that resolves to validation result
+ */
+async function validateAnthropicPdf(
+  pdfBuffer: Buffer,
+  fileSize: number,
+): Promise<PDFValidationResult> {
+  try {
+    if (fileSize > anthropicPdfSizeLimit) {
+      return {
+        isValid: false,
+        error: `PDF file size (${Math.round(fileSize / (1024 * 1024))}MB) exceeds Anthropic's 32MB limit`,
+      };
+    }
+
+    if (!pdfBuffer || pdfBuffer.length < 5) {
+      return {
+        isValid: false,
+        error: 'Invalid PDF file: too small or corrupted',
+      };
+    }
+
+    const pdfHeader = pdfBuffer.subarray(0, 5).toString();
+    if (!pdfHeader.startsWith('%PDF-')) {
+      return {
+        isValid: false,
+        error: 'Invalid PDF file: missing PDF header',
+      };
+    }
+
+    const pdfContent = pdfBuffer.toString('binary');
+    if (
+      pdfContent.includes('/Encrypt ') ||
+      pdfContent.includes('/U (') ||
+      pdfContent.includes('/O (')
+    ) {
+      return {
+        isValid: false,
+        error: 'PDF is password-protected or encrypted. Anthropic requires unencrypted PDFs.',
+      };
+    }
+
+    const pageMatches = pdfContent.match(/\/Type[\s]*\/Page[^s]/g);
+    const estimatedPages = pageMatches ? pageMatches.length : 1;
+
+    if (estimatedPages > 100) {
+      return {
+        isValid: false,
+        error: `PDF has approximately ${estimatedPages} pages, exceeding Anthropic's 100-page limit`,
+      };
+    }
+
+    return { isValid: true };
+  } catch (error) {
+    console.error('PDF validation error:', error);
+    return {
+      isValid: false,
+      error: 'Failed to validate PDF file',
+    };
+  }
+}
+
+async function validateOpenAIPdf(fileSize: number): Promise<PDFValidationResult> {
+  if (fileSize > 10 * 1024 * 1024) {
+    return {
+      isValid: false,
+      error: "PDF file size exceeds OpenAI's 10MB limit",
+    };
+  }
+
+  return { isValid: true };
+}