{"record":{"id":"9548499edd69f3bf","repo":"danny-avila/LibreChat","slug":"remote-file-response-too-large-buffer-length-b-954849","errorCode":null,"errorMessage":"Remote file response too large: ${buffer.length} bytes","messagePattern":"Remote file response too large: (.+?) bytes","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"api/server/services/Files/Firebase/crud.js","lineNumber":78,"sourceCode":"  const storage = getFirebaseStorage();\n  if (!storage) {\n    logger.error('Firebase is not initialized. Cannot save file to Firebase Storage.');\n    return null;\n  }\n\n  const storageRef = ref(storage, `${basePath}/${userId.toString()}/${fileName}`);\n  const maxBytes = getRemoteFileFetchMaxBytes();\n  const response = await fetch(assertRemoteFileURL(URL), {\n    timeout: getRemoteFileFetchTimeoutMs(),\n    size: maxBytes,\n  });\n  if (!response.ok) {\n    throw new Error(`Failed to fetch URL: ${response.status} ${response.statusText}`);\n  }\n  assertRemoteFileContentLength(response.headers, maxBytes);\n  const buffer = await response.buffer();\n  if (buffer.length > maxBytes) {\n    throw new Error(`Remote file response too large: ${buffer.length} bytes`);\n  }\n\n  try {\n    await uploadBytes(storageRef, buffer);\n    return await getBufferMetadata(buffer);\n  } catch (error) {\n    logger.error('Error uploading file to Firebase Storage:', error.message);\n    return null;\n  }\n}\n\n/**\n * Retrieves the download URL for a specified file from Firebase Storage. This function initializes the\n * Firebase Storage and generates a reference to the file based on the provided basePath and file name. If\n * Firebase Storage is not initialized or if there is an error in fetching the URL, the error is logged\n * to the console.\n *\n * @param {Object} params - The parameters object.","sourceCodeStart":60,"sourceCodeEnd":96,"githubUrl":"https://github.com/danny-avila/LibreChat/blob/5ff282f9006c436e561de1afd39a481bea1ef0d8/api/server/services/Files/Firebase/crud.js#L60-L96","documentation":"Thrown by saveURLToFirebase after fetching a remote URL with node-fetch when the downloaded buffer exceeds the configured maximum (REMOTE_FILE_FETCH_MAX_BYTES, default 512 MB). The node-fetch `size` option should reject oversized responses mid-stream, but this check fires when the final buffer length exceeds the limit anyway — a defense-in-depth guard for when the remote server lies about Content-Length or omits it entirely.","triggerScenarios":"Calling saveURLToFirebase({ URL }) where the remote host serves a file larger than REMOTE_FILE_FETCH_MAX_BYTES. This triggers when the response body is fully buffered and its length exceeds maxBytes, even though assertRemoteFileContentLength already inspected the header and node-fetch's `size` option was set.","commonSituations":"A user provides a URL to a very large image or document for upload. The remote CDN serves chunked encoding with no Content-Length, so the header-based pre-check passes but the actual body is oversized. Alternatively, REMOTE_FILE_FETCH_MAX_BYTES was lowered in .env to a restrictive value (e.g., 5 MB) and legitimate files now exceed it.","solutions":["Check whether the source URL legitimately needs to serve a large file; if so, raise REMOTE_FILE_FETCH_MAX_BYTES in your .env to accommodate it.","Verify the remote URL is correct and not accidentally pointing to a download page, HTML wrapper, or redirect chain that inflates the payload.","If the limit is intentional, validate file size before calling saveURLToFirebase by issuing a HEAD request and checking Content-Length against getRemoteFileFetchMaxBytes().","Wrap the call in a try/catch and present a user-facing error indicating the file exceeds the maximum allowed size."],"exampleFix":"// before\nconst result = await saveURLToFirebase({ userId, URL, fileName });\n\n// after — pre-check with HEAD request\nconst maxBytes = getRemoteFileFetchMaxBytes();\nconst head = await fetch(assertRemoteFileURL(URL), { method: 'HEAD', timeout: 5000 });\nconst contentLength = parseInt(head.headers.get('content-length') ?? '0', 10);\nif (contentLength > maxBytes) {\n  throw new Error(`File exceeds maximum size of ${maxBytes} bytes`);\n}\nconst result = await saveURLToFirebase({ userId, URL, fileName });","handlingStrategy":"validation","validationCode":"const maxBytes = getRemoteFileFetchMaxBytes();\nconst head = await fetch(assertRemoteFileURL(URL), { method: 'HEAD', timeout: 5000 });\nconst contentLength = parseInt(head.headers.get('content-length') ?? '0', 10);\nif (contentLength > maxBytes) {\n  throw new Error(`File exceeds maximum size of ${maxBytes} bytes`);\n}","typeGuard":null,"tryCatchPattern":"try {\n  const result = await saveURLToFirebase({ userId, URL, fileName });\n  if (!result) {\n    // handle null (init failure or upload error)\n  }\n} catch (error) {\n  if (error.message.includes('too large')) {\n    // surface user-friendly size error\n  }\n  throw error;\n}","preventionTips":["Pre-check remote file size with a HEAD request before initiating the full download.","Set REMOTE_FILE_FETCH_MAX_BYTES to a value that matches your application's actual file size needs.","Validate user-supplied URLs and reject known large-content sources at the API boundary."],"tags":["file-upload","firebase","size-limit","network","defense-in-depth"],"backgroundTag":null,"analyzedSha":"5ff282f9006c436e561de1afd39a481bea1ef0d8","analyzedAt":"2026-08-12T21:38:08.145Z","schemaVersion":2},"datasetVersion":"2026-08-12T23:17:12.415Z"}