feat: initial prototype

src/utils/calculateCost.ts

@@ -0,0 +1,31 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+import { logger } from "./logger.js";
+import type { Usage } from "@anthropic-ai/sdk/resources/index.js";
+
+/**
+ * Calculates the cost of a command run by a user, and sends to
+ * our logging service.
+ * @param usage -- The usage payload from Anthropic.
+ * @param uuid -- The Discord ID of the user who ran the command.
+ */
+export const calculateCost = async(
+  usage: Usage,
+  uuid: string,
+): Promise<void> => {
+  const inputCost = usage.input_tokens * (3 / 1_000_000);
+  const outputCost = usage.output_tokens * (15 / 1_000_000);
+  const totalCost = inputCost + outputCost;
+  await logger.log(
+    "info",
+    `User ${uuid} used the bot, which accepted ${usage.input_tokens.toString()} and generated ${usage.output_tokens.toString()}.
+    
+    Total cost: ${totalCost.toLocaleString("en-GB", {
+      currency: "USD",
+      style:    "currency",
+    })}`,
+  );
+};