technicalIndicators_minusDI
Calculate the Minus Directional Indicator (-DI) to identify bearish market trends by measuring downward price movement strength for a given stock symbol and time period.
Instructions
Minus Directional Indicator (-DI)
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| symbol | Yes | The stock symbol (e.g., "IBM"). | |
| interval | Yes | Time interval (e.g., "daily", "60min", "weekly"). Check Alpha Vantage docs for valid intervals per indicator. | |
| datatype | No | Data format for the response. | json |
| month | No | Specific month for intraday intervals (YYYY-MM format). | |
| time_period | Yes | Number of data points used to calculate the indicator. |
Implementation Reference
- src/index.ts:1397-1411 (handler)The handler implementation for the 'technicalIndicators_minusDI' tool. It registers the tool and defines the execute function that calls executeAvantageTool with the specific Alpha Vantage method av.technicalIndicators.minusDI(params).server.addTool({ name: "technicalIndicators_minusDI", description: "Minus Directional Indicator (-DI)", parameters: schemas.TechnicalIndicatorsMinusDiParamsSchema, execute: ( args, context // Let type be inferred ) => executeAvantageTool( "technicalIndicators_minusDI", args, context, (av, params) => av.technicalIndicators.minusDI(params) ), });
- src/schemas.ts:248-248 (schema)Specific parameter schema for the technicalIndicators_minusDI tool, which is an alias/description extension of the base time period schema.export const TechnicalIndicatorsMinusDiParamsSchema = TechnicalIndicatorsTimePeriodOnlyParamsSchema.describe('Parameters for MINUS_DI.');
- src/schemas.ts:239-241 (schema)Base schema TechnicalIndicatorsTimePeriodOnlyParamsSchema used by the tool's parameters, extending common indicator params with time_period.export const TechnicalIndicatorsTimePeriodOnlyParamsSchema = TechnicalIndicatorsCommonIndicatorParamsSchema.extend({ time_period: z.string().describe('Number of data points used to calculate the indicator.'), }).describe('Parameters for indicators requiring symbol, interval, and time_period.');
- src/index.ts:38-114 (helper)Shared helper function executeAvantageTool used by all tools including technicalIndicators_minusDI. Manages authentication, caching of AVantage client, executes the library method, and formats response.async function executeAvantageTool<TArgs, TResult>( toolName: string, args: TArgs, context: Context<Record<string, unknown> | undefined>, // Use the imported Context type directly avantageMethod: ( av: AVantage, args: TArgs ) => Promise<{ error?: boolean; reason?: string; data?: TResult }> ): Promise<string> { logger.info(`Executing '${toolName}' tool for request ID: ${context}`); logger.debug(`Args for ${toolName}: ${JSON.stringify(args)}`); // --- Authentication & Resource Management --- // Access extraArgs safely - it might be null or undefined const extraArgsApiKey = context.extraArgs?.apiKey as string | undefined; const apiKey = extraArgsApiKey || config.apiKey; if (!apiKey) { logger.error(`'${toolName}' failed: Alpha Vantage API key missing.`); throw new UserError(apiKeyErrorMessage); } logger.debug( `Using AV API key (source: ${extraArgsApiKey ? "extraArgs" : "environment"}) for ${toolName}` ); try { // Get or create AVantage instance managed by ResourceManager const av = await resourceManager.getResource<AVantage>( apiKey, // Cache key is the resolved API key "avantage_client", // Type identifier for logging async (key) => { // Factory Function logger.info( `Creating new AVantage instance for key ending ...${key.slice(-4)}` ); // AVantage library reads AV_PREMIUM from process.env internally return new AVantage(key); }, async (avInstance) => { // Cleanup Function (no-op needed for AVantage) logger.debug(`Destroying AVantage instance (no-op)`); } ); // --- Library Call --- const result = await avantageMethod(av, args); // --- Response Handling --- if (result.error) { logger.warn( `'${toolName}' failed. Reason from avantage: ${result.reason}` ); throw new UserError(result.reason || `Tool '${toolName}' failed.`); } if (result.data === undefined || result.data === null) { logger.warn(`'${toolName}' completed successfully but returned no data.`); return "null"; // Return string "null" for empty data } logger.info(`'${toolName}' completed successfully.`); // Stringify the data part of the response return JSON.stringify(result.data); } catch (error: any) { logger.error( `Error during execution of '${toolName}': ${error.message}`, error ); // If it's already a UserError, rethrow it if (error instanceof UserError) { throw error; } // Otherwise, wrap it in a UserError throw new UserError( `An unexpected error occurred while executing tool '${toolName}': ${error.message}` ); }