From 63030f2e3404abcd0c9635b44258941e5c18662b Mon Sep 17 00:00:00 2001
From: anshumancanrock <anshu.1239.as@gmail.com>
Date: Mon, 8 Jun 2026 18:58:07 +0530
Subject: [PATCH] feat: add NIP-70 protected event detection util

---
 .changeset/nip70-protected-event-util.md |  5 +++
 src/constants/base.ts                    |  2 +
 src/utils/event.ts                       |  6 +++
 test/unit/utils/event.spec.ts            | 54 ++++++++++++++++++++++++
 4 files changed, 67 insertions(+)
 create mode 100644 .changeset/nip70-protected-event-util.md

diff --git a/.changeset/nip70-protected-event-util.md b/.changeset/nip70-protected-event-util.md
new file mode 100644
index 00000000..7d82848d
--- /dev/null
+++ b/.changeset/nip70-protected-event-util.md
@@ -0,0 +1,5 @@
+---
+"nostream": patch
+---
+
+feat: add NIP-70 protected event detection utility
diff --git a/src/constants/base.ts b/src/constants/base.ts
index f37a41d8..d5b5f526 100644
--- a/src/constants/base.ts
+++ b/src/constants/base.ts
@@ -79,6 +79,8 @@ export enum EventTags {
   AuthRelay = 'relay',
   // Marmot Protocol MIP-03: group ID for filtering kind:445 Group Events
   Group = 'h',
+  // NIP-70: Protected Events
+  Protected = '-',
 }
 
 export const ALL_RELAYS = 'ALL_RELAYS'
diff --git a/src/utils/event.ts b/src/utils/event.ts
index 68f34b2e..b49f4bcb 100644
--- a/src/utils/event.ts
+++ b/src/utils/event.ts
@@ -289,3 +289,9 @@ export const isWelcomeRumorEvent = (event: Event): boolean => {
 export const isMarmotGroupEvent = (event: Event): boolean => {
   return event.kind === EventKinds.MARMOT_GROUP_EVENT
 }
+
+// NIP-70: Protected Events
+
+export const isProtectedEvent = (event: Event): boolean => {
+  return event.tags.some((tag) => tag[0] === EventTags.Protected)
+}
diff --git a/test/unit/utils/event.spec.ts b/test/unit/utils/event.spec.ts
index 721d767b..e91fe09b 100644
--- a/test/unit/utils/event.spec.ts
+++ b/test/unit/utils/event.spec.ts
@@ -13,6 +13,7 @@ import {
   isGiftWrapEvent,
   isMarmotGroupEvent,
   isParameterizedReplaceableEvent,
+  isProtectedEvent,
   isReplaceableEvent,
   isRequestToVanishEvent,
   isSealEvent,
@@ -655,3 +656,56 @@ describe('NIP-40', () => {
     })
   })
 })
+
+describe('NIP-70', () => {
+  describe('isProtectedEvent', () => {
+    it('returns true if event has a ["-"] tag', () => {
+      const event: Event = {
+        tags: [['-']],
+      } as any
+      expect(isProtectedEvent(event)).to.be.true
+    })
+
+    it('returns true if protected tag has extra values', () => {
+      const event: Event = {
+        tags: [['-', 'some-reason']],
+      } as any
+      expect(isProtectedEvent(event)).to.be.true
+    })
+
+    it('returns false if event has no tags', () => {
+      const event: Event = {
+        tags: [],
+      } as any
+      expect(isProtectedEvent(event)).to.be.false
+    })
+
+    it('returns false if event has unrelated tags', () => {
+      const event: Event = {
+        tags: [
+          ['e', '7377fa81fc6c7ae7f7f4ef8938d4a603f7bf98183b35ab128235cc92d4bebf96'],
+          ['p', '22e804d26ed16b68db5259e78449e96dab5d464c8f470bda3eb1a70467f2c793'],
+        ],
+      } as any
+      expect(isProtectedEvent(event)).to.be.false
+    })
+
+    it('returns false if "-" appears as a tag value, not a tag name', () => {
+      const event: Event = {
+        tags: [['e', '-']],
+      } as any
+      expect(isProtectedEvent(event)).to.be.false
+    })
+
+    it('returns true when protected tag is among other tags', () => {
+      const event: Event = {
+        tags: [
+          ['e', '7377fa81fc6c7ae7f7f4ef8938d4a603f7bf98183b35ab128235cc92d4bebf96'],
+          ['-'],
+          ['p', '22e804d26ed16b68db5259e78449e96dab5d464c8f470bda3eb1a70467f2c793'],
+        ],
+      } as any
+      expect(isProtectedEvent(event)).to.be.true
+    })
+  })
+})