File Input in MCP Tools

{
  fileName: string;       // original filename, e.g. "report.pdf"
  mimeType: string;       // e.g. "image/jpeg", "application/pdf"
  base64: string;         // full file content, base64-encoded
  size: number;           // byte length
  lastModified: Date;
}

server.registerTool(
  "process-file",
  {
    inputSchema: {
      file: z
        .object({
          fileName: z.string(),
          mimeType: z.string(),
          base64: z.string(),
          size: z.number().optional(),
        })
        .describe("File to process")
        .meta({ format: "file" }), // tells Langdock to resolve the reference
    },
  },
  async ({ file }) => {
    const buffer = Buffer.from(file.base64, "base64");
    // use buffer, file.fileName, file.mimeType, etc.
    return {
      content: [{ type: "text", text: `Processed: ${file.fileName} (${file.size} bytes)` }],
    };
  },
);

{
  "file": {
    "fileName": "example.txt",
    "mimeType": "text/plain",
    "base64": "SGVsbG8gd29ybGQ=",
    "size": 11
  }
}

{
  "success": true,
  "filename": "example.txt",
  "mimeType": "text/plain",
  "sizeBytes": 11
}