sys_base64

Instructions

Implementation Reference

• src/onion_mcp_server/tools/system.py:254-276 (handler)

  The _sys_base64 function implements the core Base64 encode/decode logic. It takes 'text', 'action' (encode/decode), and 'url_safe' parameters. For encoding, it uses base64.b64encode or base64.urlsafe_b64encode. For decoding, it handles padding and uses base64.b64decode or base64.urlsafe_b64decode. On error, it returns an error message with ❌ prefix.

  def _sys_base64(args: dict) -> list[types.TextContent]:
      text     = args["text"]
      action   = args.get("action", "encode")
      url_safe = bool(args.get("url_safe", False))
  
      try:
          if action == "encode":
              data = text.encode("utf-8")
              result = (
                  base64.urlsafe_b64encode(data)
                  if url_safe else base64.b64encode(data)
              ).decode()
          else:
              padding = 4 - len(text) % 4
              padded  = text + ("=" * (padding % 4))
              result  = (
                  base64.urlsafe_b64decode(padded)
                  if url_safe else base64.b64decode(padded)
              ).decode("utf-8")
      except Exception as e:
          return [types.TextContent(type="text", text=f"❌ {action} 失败: {e}")]
  
      return [types.TextContent(type="text", text=result)]

• src/onion_mcp_server/tools/system.py:99-123 (schema)

  The Tool definition for 'sys_base64' including the inputSchema. It defines three properties: 'text' (required string), 'action' (optional enum encode/decode, default encode), and 'url_safe' (optional boolean, default false).

  types.Tool(
      name="sys_base64",
      description="Base64 编码或解码文本。",
      inputSchema={
          "type": "object",
          "properties": {
              "text": {
                  "type":        "string",
                  "description": "要处理的文本",
              },
              "action": {
                  "type":        "string",
                  "description": "encode（编码）或 decode（解码）",
                  "enum":        ["encode", "decode"],
                  "default":     "encode",
              },
              "url_safe": {
                  "type":        "boolean",
                  "description": "是否使用 URL-safe Base64（默认 false）",
                  "default":     False,
              },
          },
          "required": ["text"],
      },
  ),

• src/onion_mcp_server/tools/system.py:175-187 (registration)

  The handle_system function acts as the dispatcher/router. It maps the tool name 'sys_base64' to the handler function _sys_base64 and calls it with the arguments dict.

  async def handle_system(name: str, arguments: dict) -> list[types.TextContent]:
      handlers = {
          "sys_time":       _sys_time,
          "sys_uuid":       _sys_uuid,
          "sys_hash":       _sys_hash,
          "sys_base64":     _sys_base64,
          "sys_url_encode": _sys_url_encode,
          "sys_json_valid": _sys_json_valid,
      }
      fn = handlers.get(name)
      if fn is None:
          raise ValueError(f"未知 system 工具: {name}")
      return fn(arguments)

• src/onion_mcp_server/tools/system.py:13-21 (helper)

  Import of the 'base64' standard library module, which provides the underlying b64encode, b64decode, urlsafe_b64encode, and urlsafe_b64decode functions used by the handler.

  import base64
  import hashlib
  import json
  import urllib.parse
  import uuid as _uuid
  from datetime import datetime
  from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
  
  import mcp.types as types