feat: add utilities/unit_converter skill

skills/utilities/unit_converter/instructions.md

@@ -0,0 +1,35 @@
+# Unit Converter Skill
+
+You have access to a unit conversion tool. Use it whenever the user asks to convert a value from one unit to another.
+
+## When to use this skill
+
+- The user mentions a numeric value alongside a unit (e.g. "100km", "70kg", "32°F")
+- The user asks "how much is X in Y"
+- The user needs a unit conversion as part of a larger calculation
+
+## Supported categories
+
+- **Length**: km, m, cm, mm, miles, yards, feet, inches
+- **Weight**: kg, g, mg, lbs, oz
+- **Temperature**: celsius, fahrenheit, kelvin
+- **Speed**: kph, mph, mps, knots
+
+## How to call the tool
+
+Always pass three parameters:
+- `value` — the numeric amount (number, not a string)
+- `from_unit` — the unit to convert from, lowercase (e.g. "celsius", "km", "lbs")
+- `to_unit` — the unit to convert to, lowercase
+
+## Handling errors
+
+If the tool returns an `error` key, explain the issue clearly to the user. Common causes:
+- Unrecognised unit name — suggest the closest supported unit
+- Mismatched categories — explain that e.g. weight cannot be converted to length
+- Missing value — ask the user to provide a numeric amount
+
+## Response style
+
+Always confirm the original value and unit alongside the result. For example:
+"100 km is equal to 62.14 miles."

skills/utilities/unit_converter/manifest.yaml

@@ -0,0 +1,34 @@
+name: "utilities/unit_converter"
+version: "0.1.0"
+description: "Converts values between common units of measurement including length, weight, temperature, and speed."
+short_description: "Converts values between common units of measurement."
+issuer:
+  name: Sameer
+  email: sam90509@gmail.comcom
+  github: sameer08055
+  org: ""
+category: "utilities"
+parameters:
+  type: object
+  properties:
+    value:
+      type: "number"
+      description: "The numeric value to convert."
+    from_unit:
+      type: "string"
+      description: "The unit to convert from (e.g. 'km', 'kg', 'celsius', 'mph')."
+    to_unit:
+      type: "string"
+      description: "The unit to convert to (e.g. 'miles', 'lbs', 'fahrenheit', 'kph')."
+  required:
+    - value
+    - from_unit
+    - to_unit
+requirements: []
+constitution: |
+  1. ACCURACY: Use standard conversion factors only. Never approximate loosely.
+  2. TRANSPARENCY: Always return the original value and units alongside the result.
+  3. SAFETY: Return a clear error if a unit is unrecognised or a conversion is physically impossible.
+presentation:
+  icon: "ruler"
+  color: "#2ecc71"

skills/utilities/unit_converter/skill.py

@@ -0,0 +1,116 @@
+from typing import Any, Dict
+from skillware.core.base_skill import BaseSkill
+
+class UnitConverterSkill(BaseSkill):
+    """
+    Converts values between common units of measurement:
+    length, weight, temperature, and speed.
+    """
+
+    @property
+    def manifest(self) -> Dict[str, Any]:
+        return {
+            "name": "utilities/unit_converter",
+            "version": "0.1.0",
+        }
+
+    CONVERSIONS = {
+        # Length — base unit: meters
+        "km":      ("length", 1000),
+        "m":       ("length", 1),
+        "cm":      ("length", 0.01),
+        "mm":      ("length", 0.001),
+        "miles":   ("length", 1609.34),
+        "mile":    ("length", 1609.34),
+        "yards":   ("length", 0.9144),
+        "feet":    ("length", 0.3048),
+        "inches":  ("length", 0.0254),
+
+        # Weight — base unit: kilograms
+        "kg":      ("weight", 1),
+        "g":       ("weight", 0.001),
+        "mg":      ("weight", 0.000001),
+        "lbs":     ("weight", 0.453592),
+        "lb":      ("weight", 0.453592),
+        "ounces":  ("weight", 0.0283495),
+        "oz":      ("weight", 0.0283495),
+
+        # Speed — base unit: meters per second
+        "mps":     ("speed", 1),
+        "kph":     ("speed", 0.277778),
+        "mph":     ("speed", 0.44704),
+        "knots":   ("speed", 0.514444),
+    }
+
+    def _convert_temperature(self, value: float, from_unit: str, to_unit: str):
+        """Temperature needs its own logic since it's not a simple multiply."""
+        f = from_unit.lower()
+        t = to_unit.lower()
+
+        # Convert to Celsius first
+        if f == "celsius":
+            celsius = value
+        elif f == "fahrenheit":
+            celsius = (value - 32) * 5 / 9
+        elif f == "kelvin":
+            celsius = value - 273.15
+        else:
+            return None
+
+        # Convert from Celsius to target
+        if t == "celsius":
+            return celsius
+        elif t == "fahrenheit":
+            return (celsius * 9 / 5) + 32
+        elif t == "kelvin":
+            return celsius + 273.15
+        else:
+            return None
+
+    def execute(self, params: Dict[str, Any]) -> Any:
+        value = params.get("value")
+        from_unit = str(params.get("from_unit", "")).lower().strip()
+        to_unit = str(params.get("to_unit", "")).lower().strip()
+
+        if value is None:
+            return {"error": "value is required."}
+        if not from_unit or not to_unit:
+            return {"error": "from_unit and to_unit are required."}
+
+        # Handle temperature separately
+        temp_units = {"celsius", "fahrenheit", "kelvin"}
+        if from_unit in temp_units or to_unit in temp_units:
+            if from_unit not in temp_units or to_unit not in temp_units:
+                return {"error": f"Cannot convert between temperature and non-temperature units."}
+            result = self._convert_temperature(value, from_unit, to_unit)
+            if result is None:
+                return {"error": f"Unrecognised temperature unit."}
+            return {
+                "original_value": value,
+                "from_unit": from_unit,
+                "to_unit": to_unit,
+                "converted_value": round(result, 6),
+            }
+
+        # Handle all other unit types
+        if from_unit not in self.CONVERSIONS:
+            return {"error": f"Unrecognised unit: '{from_unit}'."}
+        if to_unit not in self.CONVERSIONS:
+            return {"error": f"Unrecognised unit: '{to_unit}'."}
+
+        from_category, from_factor = self.CONVERSIONS[from_unit]
+        to_category, to_factor = self.CONVERSIONS[to_unit]
+
+        if from_category != to_category:
+            return {"error": f"Cannot convert '{from_unit}' ({from_category}) to '{to_unit}' ({to_category})."}
+
+        # Convert: source → base unit → target unit
+        base_value = value * from_factor
+        result = base_value / to_factor
+
+        return {
+            "original_value": value,
+            "from_unit": from_unit,
+            "to_unit": to_unit,
+            "converted_value": round(result, 6),
+        }

skills/utilities/unit_converter/test_skill.py

@@ -0,0 +1,69 @@
+import pytest
+from skills.utilities.unit_converter.skill import UnitConverterSkill
+
+@pytest.fixture
+def skill():
+    return UnitConverterSkill()
+
+
+# --- Length ---
+
+def test_km_to_miles(skill):
+    result = skill.execute({"value": 100, "from_unit": "km", "to_unit": "miles"})
+    assert abs(result["converted_value"] - 62.1371) < 0.01
+
+def test_meters_to_feet(skill):
+    result = skill.execute({"value": 1, "from_unit": "m", "to_unit": "feet"})
+    assert abs(result["converted_value"] - 3.28084) < 0.01
+
+
+# --- Weight ---
+
+def test_kg_to_lbs(skill):
+    result = skill.execute({"value": 70, "from_unit": "kg", "to_unit": "lbs"})
+    assert abs(result["converted_value"] - 154.32) < 0.01
+
+def test_oz_to_grams(skill):
+    result = skill.execute({"value": 16, "from_unit": "oz", "to_unit": "g"})
+    assert abs(result["converted_value"] - 453.59) < 0.01
+
+
+# --- Temperature ---
+
+def test_celsius_to_fahrenheit(skill):
+    result = skill.execute({"value": 100, "from_unit": "celsius", "to_unit": "fahrenheit"})
+    assert result["converted_value"] == 212.0
+
+def test_freezing_point(skill):
+    result = skill.execute({"value": 0, "from_unit": "celsius", "to_unit": "fahrenheit"})
+    assert result["converted_value"] == 32.0
+
+def test_celsius_to_kelvin(skill):
+    result = skill.execute({"value": 0, "from_unit": "celsius", "to_unit": "kelvin"})
+    assert result["converted_value"] == 273.15
+
+
+# --- Speed ---
+
+def test_mph_to_kph(skill):
+    result = skill.execute({"value": 60, "from_unit": "mph", "to_unit": "kph"})
+    assert abs(result["converted_value"] - 96.56) < 0.1
+
+
+# --- Error handling ---
+
+def test_unknown_unit(skill):
+    result = skill.execute({"value": 10, "from_unit": "furlongs", "to_unit": "km"})
+    assert "error" in result
+
+def test_mismatched_categories(skill):
+    result = skill.execute({"value": 10, "from_unit": "kg", "to_unit": "km"})
+    assert "error" in result
+
+def test_temperature_mixed_with_length(skill):
+    result = skill.execute({"value": 100, "from_unit": "celsius", "to_unit": "km"})
+    assert "error" in result
+
+def test_missing_value(skill):
+    result = skill.execute({"from_unit": "km", "to_unit": "miles"})
+    assert "error" in result