technicalIndicators_bbands
Calculate Bollinger Bands to analyze stock price volatility and identify potential overbought or oversold conditions using Alpha Vantage financial data.
Instructions
Bollinger Bands (BBANDS)
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. | |
| series_type | Yes | The desired price type. |
Implementation Reference
- src/index.ts:1457-1471 (registration)Registers the "technicalIndicators_bbands" MCP tool, providing name, description, input schema, and execute handler that delegates to the shared executeAvantageTool helper.server.addTool({ name: "technicalIndicators_bbands", description: "Bollinger Bands (BBANDS)", parameters: schemas.TechnicalIndicatorsTimeSeriesIndicatorParamsSchema, // Needs more params? Check AV docs execute: ( args, context // Let type be inferred ) => executeAvantageTool( "technicalIndicators_bbands", args, context, (av, params) => av.technicalIndicators.bbands(params) ), });
- src/schemas.ts:212-215 (schema)Zod schema defining input parameters for the BBANDS tool and similar time series technical indicators. Extends common params (symbol, interval, etc.) with time_period and series_type.export const TechnicalIndicatorsTimeSeriesIndicatorParamsSchema = TechnicalIndicatorsCommonIndicatorParamsSchema.extend({ time_period: z.string().describe('Number of data points used to calculate the indicator.'), // Using string as AV API expects string series_type: SeriesTypeSchema, }).describe('Parameters for time series based technical indicators.')
- src/index.ts:38-115 (helper)Shared helper function implementing the core tool execution logic: resolves API key, manages AVantage client lifecycle, invokes the specific library method (av.technicalIndicators.bbands(params) for this tool), handles errors, and returns JSON 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}` ); } }
- src/index.ts:1461-1470 (handler)The specific handler function passed to server.addTool.execute for this tool, which invokes the generic executeAvantageTool with the appropriate tool name and library callback.execute: ( args, context // Let type be inferred ) => executeAvantageTool( "technicalIndicators_bbands", args, context, (av, params) => av.technicalIndicators.bbands(params) ),