diff --git a/app/vibenet/library/api-types.ts b/app/vibenet/library/api-types.ts
index 31de55b..9c258f3 100644
--- a/app/vibenet/library/api-types.ts
+++ b/app/vibenet/library/api-types.ts
@@ -52,6 +52,10 @@ export type ActivityRow = {
   tx_index: number;
   log_index: number;
   tx_hash: string;
+  /**
+   * Vibescan address-activity role (vibenet APIs only — no explorer HTML there):
+   * 0 sender, 1 recipient, 2 creator, 3 token-from, 4 token-to, 5 payer.
+   */
   role: number;
   token: string | null;
 };
diff --git a/app/vibenet/library/explorer.test.ts b/app/vibenet/library/explorer.test.ts
index c2dfe18..313f618 100644
--- a/app/vibenet/library/explorer.test.ts
+++ b/app/vibenet/library/explorer.test.ts
@@ -21,6 +21,7 @@ import {
   timeFromHex,
   txTypeLabel,
   weiToEth,
+  roleLabel,
 } from './explorer';
 
 // Function fragments used to build faithful calldata for the decoders under
@@ -210,6 +211,15 @@ describe('EIP-8130 scope bitmask', () => {
   });
 });
 
+describe('address-activity role labels', () => {
+  it('maps vibescan indexer roles including EIP-8130 payer', () => {
+    expect(roleLabel(0)).toBe('sender');
+    expect(roleLabel(4)).toBe('token-to');
+    expect(roleLabel(5)).toBe('payer');
+    expect(roleLabel(99)).toBe('99');
+  });
+});
+
 describe('explorer number + type formatting', () => {
   it('formats token amounts, trimming fractional zeros', () => {
     expect(fmtTokenAmount(0n, 18)).toBe('0');
diff --git a/app/vibenet/library/explorer.ts b/app/vibenet/library/explorer.ts
index 2e12f85..b4a73e6 100644
--- a/app/vibenet/library/explorer.ts
+++ b/app/vibenet/library/explorer.ts
@@ -201,12 +201,16 @@ export function expiryLabel(expiry: number): string {
   return `expires ${new Date(expiry * 1000).toLocaleString()}`;
 }
 
+// Address-activity roles from vibenet's vibescan indexer
+// (`/api/vibenet/explorer/address/*`). Vibenet no longer ships explorer HTML —
+// this mapping is the UI for those API role integers.
 const ROLE_LABELS: Record<number, string> = {
   0: 'sender',
   1: 'recipient',
   2: 'creator',
   3: 'token-from',
   4: 'token-to',
+  5: 'payer',
 };
 
 export function roleLabel(role: number): string {