diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f21ffc4..bbfdf78 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -36,7 +36,7 @@ jobs:
         run: bunx prettier --check .
 
       - name: Type check (tsc)
-        run: bunx tsc --noEmit
+        run: bunx tsgo --noEmit
 
       - name: Run tests
         run: bun run test
diff --git a/src/zod/event.ts b/src/zod/event.ts
index d975186..5a11b22 100644
--- a/src/zod/event.ts
+++ b/src/zod/event.ts
@@ -6,6 +6,37 @@ import { eq } from "drizzle-orm";
 import { EventError } from "../errors/event";
 import { tagCache } from "../utils/tagCache";
 
+const fetchTagAmount = async (
+  tag: string,
+  notFoundMessage: string
+): Promise<number> => {
+  const cachedAmount = tagCache.get(tag);
+  if (cachedAmount !== undefined) {
+    return cachedAmount;
+  }
+
+  const db = getPostgresDB();
+  try {
+    const [tagRow] = await db
+      .select()
+      .from(tagsTable)
+      .where(eq(tagsTable.tag, tag))
+      .limit(1);
+
+    if (!tagRow) {
+      throw EventError.validationFailed(notFoundMessage);
+    }
+
+    tagCache.set(tag, tagRow.amount);
+    return tagRow.amount;
+  } catch (e) {
+    if (e instanceof EventError) {
+      throw e;
+    }
+    throw EventError.unknown(e as Error);
+  }
+};
+
 const BaseEvent = z.object({
   type: z.number(), // overwritten later by discriminators
   userId: USER_ID_CONFIG.validator,
@@ -38,37 +69,14 @@ const SDKCallEvent = BaseEvent.extend({
           ]),
         })
         .transform(async (v) => {
-          // If a tag is provided, fetch the integer value for the tag and store it into debitAmount
           if (v.debit.case === "tag") {
-            const cachedAmount = tagCache.get(v.debit.value);
-            if (cachedAmount !== undefined) {
-              return { sdkCallType: v.sdkCallType, debitAmount: cachedAmount };
-            }
-
-            const db = getPostgresDB();
-            try {
-              const [tagRow] = await db
-                .select()
-                .from(tagsTable)
-                .where(eq(tagsTable.tag, v.debit.value))
-                .limit(1);
-
-              if (!tagRow) {
-                throw EventError.validationFailed(
-                  `Tag not found: ${v.debit.value}`
-                );
-              }
-
-              tagCache.set(v.debit.value, tagRow.amount);
-              return { sdkCallType: v.sdkCallType, debitAmount: tagRow.amount };
-            } catch (e) {
-              if (e instanceof EventError) {
-                throw e;
-              }
-              throw EventError.unknown(e as Error);
-            }
+            const debitAmount = await fetchTagAmount(
+              v.debit.value,
+              `Tag not found: ${v.debit.value}`
+            );
+            return { sdkCallType: v.sdkCallType, debitAmount };
           }
-          // Otherwise use provided debitAmount (apply original transformation behavior)
+
           return {
             sdkCallType: v.sdkCallType,
             debitAmount: Math.floor(v.debit.value * 100),
@@ -112,37 +120,13 @@ const AITokenUsageEvent = BaseEvent.extend({
           ]),
         })
         .transform(async (v) => {
-          const db = getPostgresDB();
-
           // Process input debit
           let inputDebitAmount: number;
           if (v.inputDebit.case === "inputTag") {
-            const cachedAmount = tagCache.get(v.inputDebit.value);
-            if (cachedAmount !== undefined) {
-              inputDebitAmount = cachedAmount;
-            } else {
-              try {
-                const [tagRow] = await db
-                  .select()
-                  .from(tagsTable)
-                  .where(eq(tagsTable.tag, v.inputDebit.value))
-                  .limit(1);
-
-                if (!tagRow) {
-                  throw EventError.validationFailed(
-                    `Input tag not found: ${v.inputDebit.value}`,
-                  );
-                }
-
-                tagCache.set(v.inputDebit.value, tagRow.amount);
-                inputDebitAmount = tagRow.amount;
-              } catch (e) {
-                if (e instanceof EventError) {
-                  throw e;
-                }
-                throw EventError.unknown(e as Error);
-              }
-            }
+            inputDebitAmount = await fetchTagAmount(
+              v.inputDebit.value,
+              `Input tag not found: ${v.inputDebit.value}`
+            );
           } else {
             inputDebitAmount = Math.floor(v.inputDebit.value * 100);
           }
@@ -150,32 +134,10 @@ const AITokenUsageEvent = BaseEvent.extend({
           // Process output debit
           let outputDebitAmount: number;
           if (v.outputDebit.case === "outputTag") {
-            const cachedAmount = tagCache.get(v.outputDebit.value);
-            if (cachedAmount !== undefined) {
-              outputDebitAmount = cachedAmount;
-            } else {
-              try {
-                const [tagRow] = await db
-                  .select()
-                  .from(tagsTable)
-                  .where(eq(tagsTable.tag, v.outputDebit.value))
-                  .limit(1);
-
-                if (!tagRow) {
-                  throw EventError.validationFailed(
-                    `Output tag not found: ${v.outputDebit.value}`,
-                  );
-                }
-
-                tagCache.set(v.outputDebit.value, tagRow.amount);
-                outputDebitAmount = tagRow.amount;
-              } catch (e) {
-                if (e instanceof EventError) {
-                  throw e;
-                }
-                throw EventError.unknown(e as Error);
-              }
-            }
+            outputDebitAmount = await fetchTagAmount(
+              v.outputDebit.value,
+              `Output tag not found: ${v.outputDebit.value}`
+            );
           } else {
             outputDebitAmount = Math.floor(v.outputDebit.value * 100);
           }