diff --git a/lib/articleMutations.ts b/lib/articleMutations.ts
index 6da03c4..4312ee2 100644
--- a/lib/articleMutations.ts
+++ b/lib/articleMutations.ts
@@ -169,8 +169,8 @@ export async function publishSeries(params: {
   const {category} = params
   requireCategory(category)
 
-  // Map category to new system (not used but kept for future reference)
-  const _newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
+  // Map category to new system
+  const newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
 
   // Generate hash ID from series data
   const hashId = await generateSeriesHashId({
@@ -258,8 +258,8 @@ async function buildSeriesEvent(
   content: string
   tags: string[][]
 }> {
-  // Map category to new system (not used but kept for future reference)
-  const _newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
+  // Map category to new system
+  const newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
 
   // Generate hash ID from series data
   const hashId = await generateSeriesHashId({
@@ -324,8 +324,8 @@ export async function publishReview(params: {
   const {category} = params
   requireCategory(category)
 
-  // Map category to new system (not used but kept for future reference)
-  const _newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
+  // Map category to new system
+  const newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
 
   // Generate hash ID from review data
   const { generateReviewHashId } = await import('./hashIdGenerator')
@@ -417,8 +417,8 @@ async function buildReviewEvent(
   content: string
   tags: string[][]
 }> {
-  // Map category to new system (not used but kept for future reference)
-  const _newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
+  // Map category to new system
+  const newCategory = category === 'science-fiction' ? 'sciencefiction' : 'research'
 
   // Generate hash ID from review data
   const { generateReviewHashId } = await import('./hashIdGenerator')
diff --git a/lib/paymentNotes.ts b/lib/paymentNotes.ts
index 4dbf1ca..93fb9d8 100644
--- a/lib/paymentNotes.ts
+++ b/lib/paymentNotes.ts
@@ -4,7 +4,9 @@ import { PLATFORM_SERVICE } from './platformConfig'
 import { generatePurchaseHashId, generateReviewTipHashId, generateSponsoringHashId } from './hashIdGenerator'
 import { buildObjectId } from './urlGenerator'
 import type { Event, EventTemplate } from 'nostr-tools'
-import type { Purchase } from '@/types/nostr'
+import { finalizeEvent } from 'nostr-tools'
+import { hexToBytes } from 'nostr-tools/utils'
+import type { Purchase, ReviewTip, Sponsoring } from '@/types/nostr'
 import { writeOrchestrator } from './writeOrchestrator'
 
 /**