Function saveAttachment

src/runtime/adapters/attachment-utils.ts:36–59

(
  rootDir: string,
  channelId: string,
  filename: string,
  buffer: Buffer,
  mimeType?: string,
)

 * Save a buffer as an attachment file and return a ChannelAttachment descriptor.
 */
export async function saveAttachment(
  rootDir: string,
  channelId: string,
  filename: string,
  buffer: Buffer,
  mimeType?: string,
): Promise<ChannelAttachment> {
  const dir = getAttachmentDir(rootDir, channelId);
  fs.mkdirSync(dir, { recursive: true });

  const ts = Date.now();
  const safeName = sanitizeFilename(filename);
  const storedName = `${ts}-${safeName}`;
  const fullPath = path.join(dir, storedName);

  fs.writeFileSync(fullPath, buffer);

  return {
    filename,
    localPath: fullPath,
    mimeType,
    size: buffer.byteLength,
  };
}

/**
 * Download a file from a URL and save it as an attachment.