create_price_alert

Instructions

Implementation Reference

• src/tools/alerts.ts:15-28 (handler)

  The createAlertTool object defines the 'create_price_alert' tool with name, description, inputSchema (Zod validation with cardId, increasePct, decreasePct), and a handler that POSTs to '/api/v1/price-alerts' via apiFetch.

  export const createAlertTool = {
    name: "create_price_alert",
    description:
      "Create a price alert for a card. Supply increasePct, decreasePct, or both (Premium). At least one threshold is required. Requires IWMM_API_KEY.",
    inputSchema: z
      .object({
        cardId: z.string().uuid().describe("Internal IWMM card UUID."),
        increasePct: z.number().min(0.01).optional().describe("Trigger when price increases by at least this percent."),
        decreasePct: z.number().min(0.01).optional().describe("Trigger when price decreases by at least this percent."),
      })
      .refine(thresholdRefinement, { message: "Provide at least one of increasePct or decreasePct." }),
    handler: (input: { cardId: string; increasePct?: number; decreasePct?: number }) =>
      apiFetch({ path: "/api/v1/price-alerts", method: "POST", body: input, authenticated: true }),
  };

• src/tools/alerts.ts:19-25 (schema)

  Input schema for create_price_alert using Zod: cardId (UUID string), optional increasePct (number >= 0.01), optional decreasePct (number >= 0.01), with a refinement requiring at least one threshold.

  inputSchema: z
    .object({
      cardId: z.string().uuid().describe("Internal IWMM card UUID."),
      increasePct: z.number().min(0.01).optional().describe("Trigger when price increases by at least this percent."),
      decreasePct: z.number().min(0.01).optional().describe("Trigger when price decreases by at least this percent."),
    })
    .refine(thresholdRefinement, { message: "Provide at least one of increasePct or decreasePct." }),

• src/tools/index.ts:29-30 (registration)

  The createAlertTool is imported from './alerts.js' and registered in the tools array at line 80.

  listAlertsTool,
  createAlertTool,

• src/tools/index.ts:90-92 (registration)

  The toolsByName map (line 90-92) maps the string 'create_price_alert' to the createAlertTool object for dynamic lookup by name.

  export const toolsByName: Record<string, ToolDefinition> = Object.fromEntries(
    tools.map((t) => [t.name, t]),
  );

• src/server.ts:32-62 (registration)

  The MCP server's CallToolRequestSchema handler looks up the tool by name from toolsByName, validates args with the schema, and invokes the handler.

  server.setRequestHandler(CallToolRequestSchema, async (req) => {
    const tool = toolsByName[req.params.name];
    if (!tool) {
      return {
        isError: true,
        content: [{ type: "text", text: `Unknown tool: ${req.params.name}` }],
      };
    }
  
    const args = tool.inputSchema.safeParse(req.params.arguments ?? {});
    if (!args.success) {
      return {
        isError: true,
        content: [
          {
            type: "text",
            text: `Invalid arguments for ${tool.name}: ${args.error.message}`,
          },
        ],
      };
    }
  
    try {
      const result = await tool.handler(args.data);
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
      };
    } catch (err) {
      return { isError: true, content: [{ type: "text", text: formatError(err) }] };
    }
  });