s3-mcp

Instructions

Implementation Reference

• src/s3_mcp.py:353-372 (handler)

  The primary handler function for the 'upload_file' tool, registered via @mcp.tool() decorator. It calls the helper logic and formats a success response.

  @mcp.tool()
  def upload_file(
      filename: str,
      bucket: str,
      key: str,
  ) -> str:
      """Uploads a file to an S3 object.
  
      Args:
          filename (str): The path to the file to upload.
          bucket (str): The name of the bucket to upload to.
          key (str): The name of the key to upload to.
  
      Returns:
          str: JSON formatted success message.
      """
      _upload_file_logic(filename=filename, bucket=bucket, key=key)
      return format_response(
          {"status": "success", "message": f"File '{filename}' uploaded to '{bucket}/{key}'."}
      )

• src/s3_mcp.py:330-351 (helper)

  Helper function containing the core S3 upload logic using boto3's client.upload_file method.

  def _upload_file_logic(
      filename: str,
      bucket: str,
      key: str,
      extra_args: Optional[Dict[str, Any]] = None,
  ) -> None:
      """Core logic to upload a file to an S3 bucket.
  
      Args:
          filename (str): The path to the file to upload.
          bucket (str): The S3 bucket name.
          key (str): The S3 object key.
          extra_args (Optional[Dict[str, Any]]): Extra arguments for the upload.
      """
      client = get_s3_client()
      client.upload_file(
          Filename=filename,
          Bucket=bucket,
          Key=key,
          ExtraArgs=extra_args,
      )