query_exchange_rates

Instructions

Implementation Reference

• src/jexchange_mcp_server/server.py:17-47 (handler)

  The main handler function for the 'query_exchange_rates' tool. It takes from_code and to_code (3-letter currency codes), calls the JUHE exchange API via HTTP POST, and returns the exchange rate result or error message as text content.

  @mcp.tool(name="query_exchange_rates", description="根据货币的三位字母代码查询两者之间的兑换汇率")
  async def query_exchange_rates(
      from_code: str = Field(description="您希望转换的货币的三位字母货币代码。如：CNY"),
      to_code : str = Field(description="您希望转换为目标货币的三位字母货币代码。如：USD")
  ) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:
      """根据城市、地区、区县名称查询当地实时天气预报情况"""
      url = f"{JUHE_EXCHANGE_API_BASE}/currency"
      params = {
          "version": "2",
          "from": from_code,
          "to": to_code,
          "key": JUHE_EXCHANGE_API_KEY
      }
      async with httpx.AsyncClient() as client:
          response = await client.post(url, params=params)
          data = response.json()
          if data["error_code"] == 0:
              result = data["result"]
              return [
                  types.TextContent(
                      type="text",
                      text=f"{result}"
                  )
              ]
          else:
              return [
                  types.TextContent(
                      type="text",
                      text=f"Error: {data['reason']}"
                  )
              ]

• src/jexchange_mcp_server/server.py:17-17 (registration)

  Registration of the tool via @mcp.tool decorator with name='query_exchange_rates' and a description in Chinese.

  @mcp.tool(name="query_exchange_rates", description="根据货币的三位字母代码查询两者之间的兑换汇率")

• src/jexchange_mcp_server/server.py:18-21 (schema)

  Function signature and pydantic Field descriptions defining the input schema: from_code and to_code are both required strings (3-letter currency codes). The return type is list of TextContent | ImageContent | EmbeddedResource.

  async def query_exchange_rates(
      from_code: str = Field(description="您希望转换的货币的三位字母货币代码。如：CNY"),
      to_code : str = Field(description="您希望转换为目标货币的三位字母货币代码。如：USD")
  ) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:

• src/jexchange_mcp_server/server.py:14-15 (helper)

  Helper constants: API base URL and API key loaded from environment variable JUHE_EXCHANGE_API_KEY.

  JUHE_EXCHANGE_API_BASE = "http://op.juhe.cn/onebox/exchange/"
  JUHE_EXCHANGE_API_KEY = os.environ.get("JUHE_EXCHANGE_API_KEY")