Unit Converter MCP

Instructions

Implementation Reference

• src/unit_converter_mcp/server.py:283-298 (handler)

  MCP tool handler named 'convert_time' that executes the tool logic by calling the core convert_time_tool and formatting the response.

  @app.tool()
  def convert_time(
      value: Annotated[float, Field(description="Time value to convert")],
      from_unit: Annotated[TIME_UNIT, Field(description="Source unit")],
      to_unit: Annotated[TIME_UNIT, Field(description="Target unit")],
  ) -> dict:
      """Convert time between units."""
      converted_value = convert_time_tool(value, from_unit, to_unit)
      return {
          "original_value": value,
          "original_unit": from_unit,
          "converted_value": converted_value,
          "converted_unit": to_unit,
          "conversion_type": "time",
      }

• src/unit_converter_mcp/tools/time.py:27-63 (helper)

  Core helper function implementing the time conversion logic by normalizing to seconds.

  def convert_time_tool(
      value: float,
      from_unit: TIME_UNIT,
      to_unit: TIME_UNIT,
  ) -> float:
      """Convert time between units."""
  
      # Convert to seconds first
      to_seconds = {
          # sub‑second
          "picoseconds": 1e-12,
          "femtoseconds": 1e-15,
          "nanoseconds": 1e-09,
          "microseconds": 1e-06,
          "milliseconds": 0.001,
          # second and above
          "seconds": 1.0,
          "minutes": 60.0,
          "hours": 3_600.0,
          "days": 86_400.0,
          "weeks": 604_800.0,
          "fortnights": 1_209_600.0,
          # calendar averages
          "months": 2_628_000.0,  # 1/12 of avg Gregorian year
          "quarters": 7_884_000.0,  # 3 × avg month
          # optional lunar unit (keep or drop as you wish)
          "synodic months": 2_551_442.8896,  # mean lunation
          # years & multiples — now ONE canonical value
          "years": 31_556_952.0,  # average Gregorian (365.2425 d)
          "decades": 315_569_520.0,  # 10 × year
          "centuries": 3_155_695_200.0,  # 100 × year
          "millennia": 31_556_952_000.0,  # 1 000 × year
      }
  
      seconds = value * to_seconds[from_unit]
      return seconds / to_seconds[to_unit]

• src/unit_converter_mcp/tools/time.py:5-24 (schema)

  Pydantic/Literal type schema defining valid time units for input validation in the convert_time tool.

  TIME_UNIT = Literal[
      "picoseconds",
      "femtoseconds",
      "nanoseconds",
      "microseconds",
      "milliseconds",
      "seconds",
      "minutes",
      "hours",
      "days",
      "weeks",
      "fortnights",
      "months",
      "quarters",
      "synodic months",
      "years",
      "decades",
      "centuries",
      "millennia",
  ]