IBM i MCP Server

/** * @fileoverview Defines the core logic, schemas, and types for the `fetch_image_test` tool. * This tool fetches a random cat image from the public cataas.com API. * @module src/mcp-server/tools/imageTest/logic **/ import { z } from "zod"; import { JsonRpcErrorCode, McpError } from "@/types-global/errors.js"; import { fetchWithTimeout, getRequestContext, requestContextService, } from "@/utils/index.js"; import { logOperationStart } from "@/utils/internal/logging-helpers.js"; export const FetchImageTestInputSchema = z.object({ trigger: z .boolean() .optional() .default(true) .describe("A trigger to invoke the tool and fetch a new cat image."), }); export type FetchImageTestInput = z.infer<typeof FetchImageTestInputSchema>; export const FetchImageTestResponseSchema = z.object({ data: z.string().describe("Base64 encoded image data."), mimeType: z .string() .describe("The MIME type of the image (e.g., 'image/jpeg')."), }); export type FetchImageTestResponse = z.infer< typeof FetchImageTestResponseSchema >; const CAT_API_URL = "https://cataas.com/cat"; export async function fetchImageTestLogic( input: FetchImageTestInput, ): Promise<FetchImageTestResponse> { const context = getRequestContext() ?? requestContextService.createRequestContext({ operation: "fetchImageTestLogic", }); logOperationStart( context, `Executing 'fetch_image_test'. Trigger: ${input.trigger}`, ); const response = await fetchWithTimeout(CAT_API_URL, 5000, context); if (!response.ok) { throw new McpError( JsonRpcErrorCode.ServiceUnavailable, `Image API request failed: ${response.status} ${response.statusText}`, { ...context, httpStatusCode: response.status }, ); } const contentType = response.headers.get("content-type") || ""; if (!contentType.startsWith("image/")) { throw new McpError( JsonRpcErrorCode.ServiceUnavailable, "Image API returned a non-image response.", { ...context, contentType }, ); } const imageBuffer = Buffer.from(await response.arrayBuffer()); return { data: imageBuffer.toString("base64"), mimeType: contentType, }; }