calculate_sarext

Calculate the Parabolic SAR Extended (SAREXT) indicator for technical analysis of financial markets to identify potential trend reversals and stop-loss levels.

Instructions

Calculate Parabolic SAR Extended (SAREXT).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`kwargs`	Yes

Implementation Reference

src/mcp_talib/core/server.py:293-306 (handler)

MCP tool handler for 'calculate_sarext'. Delegates to the 'sarext' indicator from the registry, passing high/low prices and parameters, and returns the result.

@mcp.tool()
async def calculate_sarext(high: List[float], low: List[float], startvalue: Optional[float] = None, offsetonreverse: float = 0.0, acceleration_initlong: float = 0.02, acceleration_long: float = 0.02, acceleration_maxlong: float = 0.2, acceleration_initshort: float = 0.02, acceleration_short: float = 0.02, acceleration_maxshort: float = 0.2) -> Dict[str, Any]:
    try:
        indicator = registry.get_indicator("sarext")
        if not indicator:
            raise ValueError("SAREXT indicator not found")
        market_data = MarketData(close=[0], high=high, low=low)
        opts = {"startvalue": startvalue, "offsetonreverse": offsetonreverse, "acceleration_initlong": acceleration_initlong, "acceleration_long": acceleration_long, "acceleration_maxlong": acceleration_maxlong, "acceleration_initshort": acceleration_initshort, "acceleration_short": acceleration_short, "acceleration_maxshort": acceleration_maxshort}
        result = await indicator.calculate(market_data, opts)
        if result.success:
            return {"success": True, "values": result.values, "metadata": result.metadata}
        return {"success": False, "error": result.error_message}
    except Exception as e:
        return {"success": False, "error": str(e)}

src/mcp_talib/indicators/sarext.py:16-33 (schema)

Input schema definition for the SAREXT indicator, used by the tool handler. Defines parameters including high_prices, low_prices, and various acceleration settings.

@property
def input_schema(self) -> Dict[str, Any]:
    return {
        "type": "object",
        "properties": {
            "high_prices": {"type": "array", "items": {"type": "number"}},
            "low_prices": {"type": "array", "items": {"type": "number"}},
            "startvalue": {"type": ["number", "null"]},
            "offsetonreverse": {"type": "number", "default": 0.0},
            "acceleration_initlong": {"type": "number", "default": 0.02},
            "acceleration_long": {"type": "number", "default": 0.02},
            "acceleration_maxlong": {"type": "number", "default": 0.2},
            "acceleration_initshort": {"type": "number", "default": 0.02},
            "acceleration_short": {"type": "number", "default": 0.02},
            "acceleration_maxshort": {"type": "number", "default": 0.2},
        },
        "required": ["high_prices", "low_prices"],
    }

src/mcp_talib/indicators/sarext.py:35-62 (helper)

Core calculation logic for SAREXT indicator using TA-Lib's SAREXT function. Maps parameters and computes the Parabolic SAR - Extended values.

async def calculate(self, market_data: MarketData, options: Dict[str, Any] = None) -> IndicatorResult:
    if options is None:
        options = {}
    high = np.asarray(market_data.high or [], dtype=float)
    low = np.asarray(market_data.low or [], dtype=float)

    # Map our input option keys (snake_case) to TA-Lib SAREXT parameter names
    key_map = {
        "startvalue": "startvalue",
        "offsetonreverse": "offsetonreverse",
        "acceleration_initlong": "accelerationinitlong",
        "acceleration_long": "accelerationlong",
        "acceleration_maxlong": "accelerationmaxlong",
        "acceleration_initshort": "accelerationinitshort",
        "acceleration_short": "accelerationshort",
        "acceleration_maxshort": "accelerationmaxshort",
    }

    params = {}
    for src_key, ta_key in key_map.items():
        if src_key in options and options.get(src_key) is not None:
            params[ta_key] = options.get(src_key)

    try:
        out = ta.SAREXT(high, low, **params)
        return IndicatorResult(indicator_name=self.name, success=True, values={"sarext": out.tolist()}, metadata={"input_points": len(high), "output_points": len(out)})
    except Exception as e:
        return IndicatorResult(indicator_name=self.name, success=False, values={}, error_message=str(e))

src/mcp_talib/indicators/__init__.py:39-39 (registration)
Registration of the SAREXTIndicator class in the global indicators registry, enabling registry.get_indicator('sarext') in the tool handler.
```
registry.register("sarext", SAREXTIndicator)
```

TA-Lib MCP Server