Assigning hints to NIPs until NIP-53

Speeding up Bech32 and Hex processing
Updating Boosts and Reposts to the new way of declaring tags
Renaming the SHA256 hash tag from NIP94 to not confuse with # hashtags

quartz/src/main/java/com/vitorpamplona/quartz/experimental/nip95/header/FileStorageHeaderEvent.kt

@@ -34,7 +34,7 @@ import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -62,7 +62,7 @@ class FileStorageHeaderEvent(
 
     fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
 
-    fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/experimental/nip95/header/TagArrayBuilderExt.kt

@@ -25,7 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -37,7 +37,7 @@ import com.vitorpamplona.quartz.nip94FileMetadata.tags.TorrentInfoHash
 
 fun TagArrayBuilder<FileStorageHeaderEvent>.mimeType(mimeType: String) = add(MimeTypeTag.assemble(mimeType))
 
-fun TagArrayBuilder<FileStorageHeaderEvent>.hash(hash: HexKey) = add(HashTag.assemble(hash))
+fun TagArrayBuilder<FileStorageHeaderEvent>.hash(hash: HexKey) = add(HashSha256Tag.assemble(hash))
 
 fun TagArrayBuilder<FileStorageHeaderEvent>.fileSize(size: Int) = add(SizeTag.assemble(size))
 

quartz/src/main/java/com/vitorpamplona/quartz/experimental/profileGallery/ProfileGalleryEntryEvent.kt

@@ -31,7 +31,7 @@ import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -58,7 +58,7 @@ class ProfileGalleryEntryEvent(
 
     fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
 
-    fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/experimental/profileGallery/TagArrayBuilderExt.kt

@@ -26,7 +26,7 @@ import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -42,7 +42,7 @@ fun TagArrayBuilder<ProfileGalleryEntryEvent>.url(url: String) = add(UrlTag.asse
 
 fun TagArrayBuilder<ProfileGalleryEntryEvent>.mimeType(mimeType: String) = add(MimeTypeTag.assemble(mimeType))
 
-fun TagArrayBuilder<ProfileGalleryEntryEvent>.hash(hash: HexKey) = add(HashTag.assemble(hash))
+fun TagArrayBuilder<ProfileGalleryEntryEvent>.hash(hash: HexKey) = add(HashSha256Tag.assemble(hash))
 
 fun TagArrayBuilder<ProfileGalleryEntryEvent>.fileSize(size: Int) = add(SizeTag.assemble(size))
 

quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/RelationshipStatusEvent.kt

@@ -30,8 +30,8 @@ import com.vitorpamplona.quartz.nip01Core.core.tagArray
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.tags.dTags.dTag
 import com.vitorpamplona.quartz.nip31Alts.alt
-import com.vitorpamplona.quartz.nip51Lists.Nip51PrivateTags
 import com.vitorpamplona.quartz.nip51Lists.PrivateTagArrayEvent
+import com.vitorpamplona.quartz.nip51Lists.encryption.PrivateTagsInContent
 import com.vitorpamplona.quartz.utils.TimeUtils
 
 @Immutable
@@ -77,7 +77,7 @@ class RelationshipStatusEvent(
                     privateInitializer()
                 }
 
-            Nip51PrivateTags.encryptNip44(privateTags, signer) { content ->
+            PrivateTagsInContent.encryptNip44(privateTags, signer) { content ->
                 signer.sign(createdAt, KIND, publicTags, content, onReady)
             }
         }

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/HexKey.kt

@@ -28,3 +28,7 @@ typealias HexKey = String
 fun ByteArray.toHexKey(): HexKey = Hex.encode(this)
 
 fun HexKey.hexToByteArray(): ByteArray = Hex.decode(this)
+
+const val PUBKEY_LENGTH = 64
+
+const val EVENT_ID_LENGTH = 64

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/Tag.kt

@@ -22,6 +22,16 @@ package com.vitorpamplona.quartz.nip01Core.core
 
 typealias Tag = Array<String>
 
+/**
+ * Returns if the Tag has at least $index elements.
+ */
+fun Tag.has(index: Int) = size > index
+
+/**
+ * Returns if the Tag has less than $index elements.
+ */
+fun Tag.lacks(index: Int) = size <= index
+
 fun Tag.name() = this[0]
 
 fun Tag.value() = this[1]

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/hints/HintProviders.kt

@@ -24,10 +24,14 @@ import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 
-interface HintProvider {
-    fun eventHints(): EventIdHint
-
-    fun addressIdHints(): AddressHint
-
-    fun pubKeyHints(): PubKeyHint
+interface EventHintProvider {
+    fun eventHints(): List<EventIdHint>
+}
+
+interface AddressHintProvider {
+    fun addressHints(): List<AddressHint>
+}
+
+interface PubKeyHintProvider {
+    fun pubKeyHints(): List<PubKeyHint>
 }

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/addressables/ATag.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.match
 import com.vitorpamplona.quartz.nip01Core.core.name
 import com.vitorpamplona.quartz.nip01Core.core.value
+import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
@@ -128,6 +129,12 @@ data class ATag(
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): AddressHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            return AddressHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             aTagId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/events/ETag.kt

@@ -22,6 +22,7 @@ package com.vitorpamplona.quartz.nip01Core.tags.events
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
@@ -58,7 +59,7 @@ data class ETag(
         const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTagged(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun isTagged(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].length == 64
 
         @JvmStatic
         fun isTagged(
@@ -68,16 +69,22 @@ data class ETag(
 
         @JvmStatic
         fun parse(tag: Array<String>): ETag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
             return ETag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
         fun parseId(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): EventIdHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return EventIdHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             eventId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/HashtagTag.kt

@@ -20,7 +20,7 @@
  */
 package com.vitorpamplona.quartz.nip01Core.tags.hashtags
 
-class HashTag {
+class HashtagTag {
     companion object {
         const val TAG_NAME = "t"
         const val TAG_SIZE = 2
@@ -30,7 +30,7 @@ class HashTag {
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
             return tag[1]
         }
 

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/TagArrayBuilderExt.kt

@@ -23,6 +23,6 @@ package com.vitorpamplona.quartz.nip01Core.tags.hashtags
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 
-fun <T : Event> TagArrayBuilder<T>.hashtag(tag: String) = addAll(HashTag.assembleDualCase(tag))
+fun <T : Event> TagArrayBuilder<T>.hashtag(tag: String) = addAll(HashtagTag.assembleDualCase(tag))
 
-fun <T : Event> TagArrayBuilder<T>.hashtags(tag: List<String>) = addAll(HashTag.assemble(tag))
+fun <T : Event> TagArrayBuilder<T>.hashtags(tag: List<String>) = addAll(HashtagTag.assemble(tag))

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/TagArrayExt.kt

@@ -30,18 +30,18 @@ import com.vitorpamplona.quartz.nip01Core.core.isAnyLowercaseTagged
 import com.vitorpamplona.quartz.nip01Core.core.isTagged
 import com.vitorpamplona.quartz.nip01Core.core.mapValues
 
-fun TagArray.forEachHashTag(onEach: (eventId: HexKey) -> Unit) = this.forEachTagged(HashTag.TAG_NAME, onEach)
+fun TagArray.forEachHashTag(onEach: (eventId: HexKey) -> Unit) = this.forEachTagged(HashtagTag.TAG_NAME, onEach)
 
-fun TagArray.anyHashTag(onEach: (str: String) -> Boolean) = this.anyTagged(HashTag.TAG_NAME, onEach)
+fun TagArray.anyHashTag(onEach: (str: String) -> Boolean) = this.anyTagged(HashtagTag.TAG_NAME, onEach)
 
-fun TagArray.hasHashtags() = this.hasTagWithContent(HashTag.TAG_NAME)
+fun TagArray.hasHashtags() = this.hasTagWithContent(HashtagTag.TAG_NAME)
 
-fun TagArray.hashtags() = this.mapValues(HashTag.TAG_NAME)
+fun TagArray.hashtags() = this.mapValues(HashtagTag.TAG_NAME)
 
-fun TagArray.countHashtags() = this.count(HashTag::isTagged)
+fun TagArray.countHashtags() = this.count(HashtagTag::isTagged)
 
-fun TagArray.isTaggedHash(hashtag: String) = this.isTagged(HashTag.TAG_NAME, hashtag, true)
+fun TagArray.isTaggedHash(hashtag: String) = this.isTagged(HashtagTag.TAG_NAME, hashtag, true)
 
-fun TagArray.isTaggedHashes(hashtags: Set<String>) = this.isAnyLowercaseTagged(HashTag.TAG_NAME, hashtags)
+fun TagArray.isTaggedHashes(hashtags: Set<String>) = this.isAnyLowercaseTagged(HashtagTag.TAG_NAME, hashtags)
 
-fun TagArray.firstIsTaggedHashes(hashtags: Set<String>) = this.firstAnyLowercaseTaggedValue(HashTag.TAG_NAME, hashtags)
+fun TagArray.firstIsTaggedHashes(hashtags: Set<String>) = this.firstAnyLowercaseTaggedValue(HashtagTag.TAG_NAME, hashtags)

quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/people/PTag.kt

@@ -25,7 +25,7 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
-import com.vitorpamplona.quartz.nip01Core.core.isNotName
+import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip19Bech32.entities.NProfile
 import com.vitorpamplona.quartz.nip19Bech32.toNpub
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
@@ -59,14 +59,14 @@ data class PTag(
 
         @JvmStatic
         fun parse(tag: Tag): PTag? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
             if (tag[1].length != 64) return null
             return PTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
         fun parseKey(tag: Array<String>): HexKey? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
             if (tag[1].length != 64) {
                 Log.w("PTag", "Invalid `$TAG_NAME` value ${tag.joinToString(", ")}")
                 return null
@@ -74,6 +74,12 @@ data class PTag(
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): PubKeyHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return PubKeyHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             pubkey: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/ContactListEvent.kt

@@ -23,6 +23,8 @@ package com.vitorpamplona.quartz.nip02FollowList
 import androidx.compose.runtime.Stable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerSync
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
@@ -32,8 +34,9 @@ import com.vitorpamplona.quartz.nip01Core.tags.geohash.isTaggedGeoHash
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.countHashtags
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.isTaggedHash
-import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.isTaggedUser
+import com.vitorpamplona.quartz.nip02FollowList.tags.AddressFollowTag
+import com.vitorpamplona.quartz.nip02FollowList.tags.ContactTag
 import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.utils.TimeUtils
 
@@ -45,7 +48,13 @@ class ContactListEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    AddressHintProvider,
+    PubKeyHintProvider {
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
+    override fun pubKeyHints() = tags.mapNotNull(ContactTag::parseAsHint)
+
     /**
      * Returns a list of p-tags that are verified as hex keys.
      */
@@ -54,9 +63,9 @@ class ContactListEvent(
     /**
      * Returns a list of a-tags that are verified as correct.
      */
-    fun verifiedFollowAddressSet(): Set<HexKey> = tags.mapNotNullTo(HashSet(), ATag::parseValidAddress)
+    fun verifiedFollowAddressSet(): Set<HexKey> = tags.mapNotNullTo(HashSet(), AddressFollowTag::parseValidAddress)
 
-    fun unverifiedFollowKeySet() = tags.mapNotNull(PTag::parseKey)
+    fun unverifiedFollowKeySet() = tags.mapNotNull(ContactTag::parseKey)
 
     fun unverifiedFollowTagSet() = tags.hashtags()
 

quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/AddressFollowTag.kt

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip02FollowList.tags
+
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
+
+typealias AddressFollowTag = ATag

quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/ContactTag.kt

@@ -18,12 +18,13 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.quartz.nip02FollowList
+package com.vitorpamplona.quartz.nip02FollowList.tags
 
 import android.util.Log
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip19Bech32.decodePublicKey
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
@@ -62,13 +63,13 @@ data class ContactTag(
 
         @JvmStatic
         fun parse(tag: Array<String>): ContactTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
             return ContactTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
         fun parseValid(tag: Array<String>): ContactTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
             return try {
                 ContactTag(decodePublicKey(tag[1]).toHexKey(), tag.getOrNull(2), tag.getOrNull(3))
             } catch (e: Exception) {
@@ -77,9 +78,15 @@ data class ContactTag(
             }
         }
 
+        @JvmStatic
+        fun parseKey(tag: Array<String>): String? {
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            return tag[1]
+        }
+
         @JvmStatic
         fun parseValidKey(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
             return try {
                 decodePublicKey(tag[1]).toHexKey()
             } catch (e: Exception) {
@@ -88,6 +95,12 @@ data class ContactTag(
             }
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): PubKeyHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return PubKeyHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             pubkey: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip03Timestamp/OtsEvent.kt

@@ -26,10 +26,9 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
-import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
-import com.vitorpamplona.quartz.nip01Core.tags.events.eTag
-import com.vitorpamplona.quartz.nip01Core.tags.kinds.kind
+import com.vitorpamplona.quartz.nip03Timestamp.tags.TargetEventTag
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.utils.TimeUtils
 import java.util.Base64
@@ -42,10 +41,13 @@ class OtsEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider {
+    override fun eventHints() = tags.mapNotNull(TargetEventTag::parseAsHint)
+
     override fun isContentEncoded() = true
 
-    fun digestEventId() = tags.firstNotNullOfOrNull(ETag::parseId)
+    fun digestEventId() = tags.firstNotNullOfOrNull(TargetEventTag::parseId)
 
     fun otsByteArray(): ByteArray = decodeOtsState(content)
 
@@ -82,7 +84,7 @@ class OtsEvent(
             initializer: TagArrayBuilder<OtsEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, encodeOtsState(otsState), createdAt) {
             alt(ALT)
-            eTag(ETag(eventId))
+            targetEvent(TargetEventTag(eventId))
 
             initializer()
         }
@@ -95,8 +97,8 @@ class OtsEvent(
         ) = eventTemplate(KIND, encodeOtsState(otsState), createdAt) {
             alt(ALT)
 
-            eTag(event.toETag())
-            kind(event.event.kind)
+            targetEvent(event.toETag())
+            targetKind(event.event.kind)
 
             initializer()
         }

quartz/src/main/java/com/vitorpamplona/quartz/nip03Timestamp/TagArrayBuilderExt.kt

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip03Timestamp
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip03Timestamp.tags.TargetEventKindTag
+import com.vitorpamplona.quartz.nip03Timestamp.tags.TargetEventTag
+
+fun <T : Event> TagArrayBuilder<T>.targetEvent(tag: TargetEventTag) = add(tag.toTagArray())
+
+fun <T : Event> TagArrayBuilder<T>.targetEvents(tag: List<TargetEventTag>) = addAll(tag.map { it.toTagArray() })
+
+fun <T : Event> TagArrayBuilder<T>.targetKind(kind: Int) = add(TargetEventKindTag.assemble(kind))
+
+fun <T : Event> TagArrayBuilder<T>.targetKinds(kinds: List<Int>) = addAll(TargetEventKindTag.assemble(kinds))
+
+fun <T : Event> TagArrayBuilder<T>.targetKinds(kinds: Set<Int>) = addAll(TargetEventKindTag.assemble(kinds))

quartz/src/main/java/com/vitorpamplona/quartz/nip03Timestamp/tags/TargetEventKindTag.kt

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip03Timestamp.tags
+
+import com.vitorpamplona.quartz.nip01Core.tags.kinds.KindTag
+
+typealias TargetEventKindTag = KindTag

quartz/src/main/java/com/vitorpamplona/quartz/nip03Timestamp/tags/TargetEventTag.kt

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip03Timestamp.tags
+
+import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
+
+typealias TargetEventTag = ETag

quartz/src/main/java/com/vitorpamplona/quartz/nip09Deletions/DeletionEvent.kt

@@ -25,6 +25,8 @@ import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.aTag
@@ -48,7 +50,13 @@ class DeletionEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    AddressHintProvider {
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
     fun deleteEvents() = taggedEvents()
 
     fun deleteEventIds() = taggedEventIds()

quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/BaseThreadedEvent.kt

@@ -23,12 +23,18 @@ package com.vitorpamplona.quartz.nip10Notes
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.taggedATags
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.taggedUsers
 import com.vitorpamplona.quartz.nip10Notes.content.findIndexTagsWithEventsOrAddresses
 import com.vitorpamplona.quartz.nip10Notes.content.findIndexTagsWithPeople
 import com.vitorpamplona.quartz.nip10Notes.content.findNostrUris
 import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip19Bech32.entities.NAddress
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEmbed
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
@@ -48,7 +54,16 @@ open class BaseThreadedEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+) : Event(id, pubKey, createdAt, kind, tags, content, sig),
+    EventHintProvider,
+    AddressHintProvider,
+    PubKeyHintProvider {
+    override fun eventHints() = tags.mapNotNull(MarkedETag::parseAsHint) + tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint) + tags.mapNotNull(QTag::parseAddressAsHint)
+
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
     fun mentions() = taggedUsers()
 
     fun markedRoot() = tags.firstNotNullOfOrNull(MarkedETag::parseRoot)

quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/MarkedETag.kt

@@ -22,6 +22,7 @@ package com.vitorpamplona.quartz.nip10Notes.tags
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.GenericETag
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
@@ -180,6 +181,12 @@ data class MarkedETag(
                 null
             }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): EventIdHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return EventIdHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun parseRoot(tag: Array<String>): MarkedETag? {
             if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null

quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/base/BaseDMGroupEvent.kt

@@ -22,6 +22,7 @@ package com.vitorpamplona.quartz.nip17Dm.base
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip59Giftwrap.WrappedEvent
 import kotlinx.collections.immutable.toImmutableSet
@@ -37,7 +38,10 @@ open class BaseDMGroupEvent(
     sig: HexKey,
 ) : WrappedEvent(id, pubKey, createdAt, kind, tags, content, sig),
     ChatroomKeyable,
-    NIP17Group {
+    NIP17Group,
+    PubKeyHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
     /** Recipients intended to receive this conversation */
     fun recipients() = tags.mapNotNull(PTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/ChatMessageEncryptedFileHeaderEvent.kt

@@ -37,7 +37,7 @@ import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.OriginalHashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.SizeTag
 import com.vitorpamplona.quartz.utils.TimeUtils
@@ -57,7 +57,7 @@ class ChatMessageEncryptedFileHeaderEvent(
 
     fun mimeType() = tags.firstNotNullOfOrNull(FileTypeTag::parse)
 
-    fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/TagArrayBuilderExt.kt

@@ -35,7 +35,7 @@ import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.OriginalHashTag
@@ -61,7 +61,7 @@ fun TagArrayBuilder<ChatMessageEncryptedFileHeaderEvent>.encryptionNonce(nonce:
 
 fun TagArrayBuilder<ChatMessageEncryptedFileHeaderEvent>.mimeType(mimeType: String) = add(FileTypeTag.assemble(mimeType))
 
-fun TagArrayBuilder<ChatMessageEncryptedFileHeaderEvent>.hash(hash: HexKey) = add(HashTag.assemble(hash))
+fun TagArrayBuilder<ChatMessageEncryptedFileHeaderEvent>.hash(hash: HexKey) = add(HashSha256Tag.assemble(hash))
 
 fun TagArrayBuilder<ChatMessageEncryptedFileHeaderEvent>.fileSize(size: Int) = add(SizeTag.assemble(size))
 

quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionNonce.kt

@@ -38,6 +38,6 @@ class EncryptionNonce {
         }
 
         @JvmStatic
-        fun assemble(nonce: ByteArray) = arrayOf(EncryptionKey.TAG_NAME, nonce.toHexKey())
+        fun assemble(nonce: ByteArray) = arrayOf(TAG_NAME, nonce.toHexKey())
     }
 }

quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/GenericRepostEvent.kt

@@ -25,8 +25,12 @@ import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.aTag
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.events.eTag
@@ -45,10 +49,29 @@ class GenericRepostEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
-    fun boostedPost() = tags.filter { it.firstOrNull() == "e" }.mapNotNull { it.getOrNull(1) }
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
 
-    fun originalAuthor() = tags.filter { it.firstOrNull() == "p" }.mapNotNull { it.getOrNull(1) }
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
+    fun boostedEvents() = tags.mapNotNull(ETag::parse)
+
+    fun boostedATags() = tags.mapNotNull(ATag::parse)
+
+    fun boostedAddresses() = tags.mapNotNull(ATag::parseAddress)
+
+    fun originalAuthors() = tags.mapNotNull(PTag::parse)
+
+    fun boostedEventIds() = tags.mapNotNull(ETag::parseId)
+
+    fun boostedAddressIds() = tags.mapNotNull(ATag::parseAddressId)
+
+    fun originalAuthorKeys() = tags.mapNotNull(PTag::parseKey)
 
     fun containedPost() =
         try {

quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/RepostEvent.kt

@@ -25,15 +25,17 @@ import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.aTag
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.events.eTag
-import com.vitorpamplona.quartz.nip01Core.tags.events.taggedEvents
 import com.vitorpamplona.quartz.nip01Core.tags.kinds.kind
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.pTag
-import com.vitorpamplona.quartz.nip01Core.tags.people.taggedUsers
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.utils.TimeUtils
 
@@ -45,10 +47,29 @@ class RepostEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
-    fun boostedPost() = taggedEvents()
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
 
-    fun originalAuthor() = taggedUsers()
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
+    fun boostedEvents() = tags.mapNotNull(ETag::parse)
+
+    fun boostedATags() = tags.mapNotNull(ATag::parse)
+
+    fun boostedAddresses() = tags.mapNotNull(ATag::parseAddress)
+
+    fun originalAuthors() = tags.mapNotNull(PTag::parse)
+
+    fun boostedEventIds() = tags.mapNotNull(ETag::parseId)
+
+    fun boostedAddressIds() = tags.mapNotNull(ATag::parseAddressId)
+
+    fun originalAuthorKeys() = tags.mapNotNull(PTag::parseKey)
 
     fun containedPost() =
         try {

quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QTag.kt

@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip18Reposts.quotes
 
+import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
+
 interface QTag {
     fun toTagArray(): Array<String>
 
@@ -36,5 +39,17 @@ interface QTag {
                 QAddressableTag.parse(tag)
             }
         }
+
+        @JvmStatic
+        fun parseEventAsHint(tag: Array<String>): EventIdHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return EventIdHint(tag[1], tag[2])
+        }
+
+        @JvmStatic
+        fun parseAddressAsHint(tag: Array<String>): AddressHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            return AddressHint(tag[1], tag[2])
+        }
     }
 }

quartz/src/main/java/com/vitorpamplona/quartz/nip19Bech32/bech32/Bech32Util.kt

@@ -51,6 +51,12 @@ object Bech32 {
     const val ALPHABET: String = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
     const val ALPHABET_UPPERCASE: String = "QPZRY9X8GF2TVDW0S3JN54KHCE6MUA7L"
 
+    private const val GEN0 = 0x3b6a57b2
+    private const val GEN1 = 0x26508e6d
+    private const val GEN2 = 0x1ea119fa
+    private const val GEN3 = 0x3d4233dd
+    private const val GEN4 = 0x2a1462b3
+
     enum class Encoding(
         val constant: Int,
     ) {
@@ -74,17 +80,17 @@ object Bech32 {
     fun expand(hrp: String): Array<Int5> {
         val half = hrp.length + 1
         val size = half + hrp.length
+        val firstPart = hrp.indices
+        val secondPart = half until size
         return Array<Int5>(size) {
             when (it) {
-                in hrp.indices -> hrp[it].code.shr(5).toByte()
-                in half until size -> (hrp[it - half].code and 31).toByte()
+                in firstPart -> hrp[it].code.shr(5).toByte()
+                in secondPart -> (hrp[it - half].code and 31).toByte()
                 else -> 0
             }
         }
     }
 
-    private val GEN = arrayOf(0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3)
-
     fun polymod(
         values: Array<Int5>,
         values1: Array<Int5>,
@@ -93,16 +99,20 @@ object Bech32 {
         values.forEach { v ->
             val b = chk shr 25
             chk = ((chk and 0x1ffffff) shl 5) xor v.toInt()
-            for (i in 0..4) {
-                if (((b shr i) and 1) != 0) chk = chk xor GEN[i]
-            }
+            if (((b shr 0) and 1) != 0) chk = chk xor GEN0
+            if (((b shr 1) and 1) != 0) chk = chk xor GEN1
+            if (((b shr 2) and 1) != 0) chk = chk xor GEN2
+            if (((b shr 3) and 1) != 0) chk = chk xor GEN3
+            if (((b shr 4) and 1) != 0) chk = chk xor GEN4
         }
         values1.forEach { v ->
             val b = chk shr 25
             chk = ((chk and 0x1ffffff) shl 5) xor v.toInt()
-            for (i in 0..4) {
-                if (((b shr i) and 1) != 0) chk = chk xor GEN[i]
-            }
+            if (((b shr 0) and 1) != 0) chk = chk xor GEN0
+            if (((b shr 1) and 1) != 0) chk = chk xor GEN1
+            if (((b shr 2) and 1) != 0) chk = chk xor GEN2
+            if (((b shr 3) and 1) != 0) chk = chk xor GEN3
+            if (((b shr 4) and 1) != 0) chk = chk xor GEN4
         }
         return chk
     }
@@ -128,8 +138,7 @@ object Bech32 {
                 else -> addChecksum(hrp, int5s, encoding)
             }
 
-        val charArray =
-            CharArray(dataWithChecksum.size) { ALPHABET[dataWithChecksum[it].toInt()] }.concatToString()
+        val charArray = CharArray(dataWithChecksum.size) { ALPHABET[dataWithChecksum[it].toInt()] }.concatToString()
 
         return hrp + "1" + charArray
     }
@@ -231,8 +240,8 @@ object Bech32 {
     @JvmStatic
     public fun eight2five(input: ByteArray): ArrayList<Int5> {
         var buffer = 0L
-        val output =
-            ArrayList<Int5>(input.size * 2) // larger array on purpose. Checksum is added later.
+        // larger array on purpose. Checksum is added later.
+        val output = ArrayList<Int5>(input.size * 2)
         var count = 0
         input.forEach { b ->
             buffer = (buffer shl 8) or (b.toLong() and 0xff)

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/CommentEvent.kt

@@ -25,7 +25,10 @@ import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
 import com.vitorpamplona.quartz.nip21UriScheme.toNostrUri
@@ -53,7 +56,16 @@ class CommentEvent(
     content: String,
     sig: HexKey,
 ) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
-    RootScope {
+    RootScope,
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(RootAuthorTag::parseAsHint) + tags.mapNotNull(ReplyAuthorTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(RootEventTag::parseAsHint) + tags.mapNotNull(ReplyEventTag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(RootAddressTag::parseAsHint) + tags.mapNotNull(ReplyAddressTag::parseAsHint)
+
     fun rootAuthor() = tags.firstNotNullOfOrNull(RootAuthorTag::parse)
 
     fun replyAuthor() = tags.firstNotNullOfOrNull(ReplyAuthorTag::parse)

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAddressTag.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.match
 import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -51,6 +52,12 @@ class ReplyAddressTag(
         @JvmStatic
         fun parseAddress(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): AddressHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            return AddressHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             addressId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAuthorTag.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.match
+import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -55,6 +56,12 @@ data class ReplyAuthorTag(
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): PubKeyHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return PubKeyHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             pubkey: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyEventTag.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.match
 import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.EventReference
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -71,6 +72,12 @@ class ReplyEventTag(
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): EventIdHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return EventIdHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             eventId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAddressTag.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.match
 import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -69,6 +70,12 @@ class RootAddressTag(
         @JvmStatic
         fun parseAddress(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): AddressHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            return AddressHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             addressId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAuthorTag.kt

@@ -22,10 +22,13 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.PUBKEY_LENGTH
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
+import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
 
 @Immutable
 data class RootAuthorTag(
@@ -36,25 +39,45 @@ data class RootAuthorTag(
 
     companion object {
         const val TAG_NAME = "P"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.size > 1 && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Tag): ReplyAuthorTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            if (tag.size < 2 || tag[0] != TAG_NAME || tag[1].length != PUBKEY_LENGTH) return null
+            return ReplyAuthorTag(tag[1], tag.getOrNull(2))
+        }
+
+        @JvmStatic
+        fun parse3(tag: Tag): ReplyAuthorTag? {
+            ensure(tag.size >= 2) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == PUBKEY_LENGTH) { return null }
             return ReplyAuthorTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
         fun parseKey(tag: Tag): HexKey? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            if (tag.size < 2 || tag[0] != TAG_NAME || tag[1].length != PUBKEY_LENGTH) return null
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): PubKeyHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != PUBKEY_LENGTH || tag[2].isEmpty()) return null
+            return PubKeyHint(tag[1], tag[2])
+        }
+
+        @OptIn(ExperimentalContracts::class)
+        inline fun ensure(
+            condition: Boolean,
+            exit: () -> Nothing,
+        ) {
+            contract { returns() implies condition }
+            if (!condition) exit()
+        }
+
         @JvmStatic
         fun assemble(
             pubkey: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootEventTag.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.match
 import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.EventReference
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -71,6 +72,12 @@ class RootEventTag(
             return tag[1]
         }
 
+        @JvmStatic
+        fun parseAsHint(tag: Array<String>): EventIdHint? {
+            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            return EventIdHint(tag[1], tag[2])
+        }
+
         @JvmStatic
         fun assemble(
             eventId: HexKey,

quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/LongTextNoteEvent.kt

@@ -24,12 +24,17 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.nip01Core.tags.dTags.dTag
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.ImageTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.PublishedAtTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.SummaryTag
@@ -47,7 +52,16 @@ class LongTextNoteEvent(
     content: String,
     sig: HexKey,
 ) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
-    AddressableEvent {
+    AddressableEvent,
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(QTag::parseAddressAsHint)
+
     override fun dTag() = tags.dTag()
 
     override fun aTag(relayHint: String?) = ATag(kind, pubKey, dTag(), relayHint)

quartz/src/main/java/com/vitorpamplona/quartz/nip25Reactions/ReactionEvent.kt

@@ -24,8 +24,12 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.aTag
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.events.eTag
@@ -44,7 +48,16 @@ class ReactionEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
     fun originalPost() = tags.mapNotNull(ETag::parseId)
 
     fun originalAuthor() = tags.mapNotNull(PTag::parseKey)

quartz/src/main/java/com/vitorpamplona/quartz/nip28PublicChat/admin/ChannelCreateEvent.kt

@@ -24,6 +24,8 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip28PublicChat.base.ChannelData
 import com.vitorpamplona.quartz.nip31Alts.alt
@@ -37,7 +39,10 @@ class ChannelCreateEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider {
+    override fun eventHints() = channelInfo().relays?.map { EventIdHint(id, it) } ?: emptyList()
+
     fun channelInfo() = ChannelData.parse(content) ?: ChannelData()
 
     companion object {

quartz/src/main/java/com/vitorpamplona/quartz/nip28PublicChat/admin/ChannelHideMessageEvent.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.events.eTags
@@ -41,7 +42,10 @@ class ChannelHideMessageEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider {
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint)
+
     fun eventsToHide() = tags.taggedEventIds()
 
     companion object {

quartz/src/main/java/com/vitorpamplona/quartz/nip28PublicChat/admin/ChannelMetadataEvent.kt

@@ -24,6 +24,8 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip28PublicChat.base.BasePublicChatEvent
@@ -40,7 +42,10 @@ class ChannelMetadataEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider {
+    override fun eventHints() = channelInfo().relays?.map { EventIdHint(id, it) } ?: emptyList()
+
     fun channelInfo() = ChannelData.parse(content) ?: ChannelData()
 
     companion object {

quartz/src/main/java/com/vitorpamplona/quartz/nip28PublicChat/admin/ChannelMuteUserEvent.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.pTags
@@ -41,7 +42,10 @@ class ChannelMuteUserEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BasePublicChatEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    PubKeyHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
     fun usersToMute() = tags.taggedUserIds()
 
     companion object {

quartz/src/main/java/com/vitorpamplona/quartz/nip30CustomEmoji/selection/EmojiPackSelectionEvent.kt

@@ -24,9 +24,11 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.BaseReplaceableEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.signers.eventUpdate
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.taggedATags
 import com.vitorpamplona.quartz.nip30CustomEmoji.pack.EmojiPackEvent
@@ -41,7 +43,10 @@ class EmojiPackSelectionEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BaseReplaceableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseReplaceableEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    AddressHintProvider {
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
     fun emojiPacks() = taggedATags()
 
     companion object {

quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/issue/GitIssueEvent.kt

@@ -23,13 +23,17 @@ package com.vitorpamplona.quartz.nip34Git.issue
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
 import com.vitorpamplona.quartz.nip14Subject.SubjectTag
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip34Git.repository.GitRepositoryEvent
 import com.vitorpamplona.quartz.utils.TimeUtils
@@ -42,7 +46,16 @@ class GitIssueEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    PubKeyHintProvider,
+    EventHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint) + tags.mapNotNull(QTag::parseAddressAsHint)
+
     fun repositoryHex() = tags.firstNotNullOfOrNull(ATag::parseAddressId)
 
     fun repositoryAddress() = tags.firstNotNullOfOrNull(ATag::parseAddress)

quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/patch/GitPatchEvent.kt

@@ -23,9 +23,14 @@ package com.vitorpamplona.quartz.nip34Git.patch
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.utils.TimeUtils
 
@@ -37,7 +42,16 @@ class GitPatchEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig),
+    PubKeyHintProvider,
+    EventHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(MarkedETag::parseAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
     private fun innerRepository() =
         tags.firstOrNull { it.size > 3 && it[0] == "a" && it[3] == "root" }
             ?: tags.firstOrNull { it.size > 1 && it[0] == "a" }

quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/reply/GitReplyEvent.kt

@@ -23,13 +23,18 @@ package com.vitorpamplona.quartz.nip34Git.reply
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
 import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip10Notes.tags.markedETags
 import com.vitorpamplona.quartz.nip10Notes.tags.prepareMarkedETagsAsReplyTo
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip34Git.issue.GitIssueEvent
 import com.vitorpamplona.quartz.nip34Git.patch.GitPatchEvent
 import com.vitorpamplona.quartz.utils.TimeUtils
@@ -43,7 +48,16 @@ class GitReplyEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    PubKeyHintProvider,
+    EventHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(MarkedETag::parseAsHint) + tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint) + tags.mapNotNull(QTag::parseAddressAsHint)
+
     fun repositoryHex() = tags.firstNotNullOfOrNull(ATag::parseAddressId)
 
     fun repository() = tags.firstNotNullOfOrNull(ATag::parse)

quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/TorrentCommentEvent.kt

@@ -23,15 +23,20 @@ package com.vitorpamplona.quartz.nip35Torrents
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.EventTemplate
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.events.eTags
 import com.vitorpamplona.quartz.nip01Core.tags.events.taggedEvents
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
 import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip10Notes.tags.positionalMarkedTags
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.utils.TimeUtils
 
@@ -43,7 +48,16 @@ class TorrentCommentEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint) + tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(QTag::parseAddressAsHint)
+
     fun torrent() = tags.firstNotNullOfOrNull(MarkedETag::parseRoot) ?: tags.firstNotNullOfOrNull(ETag::parse)
 
     fun torrentIds() = tags.firstNotNullOfOrNull(MarkedETag::parseRootId) ?: tags.firstNotNullOfOrNull(ETag::parseId)

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/GeneralListEvent.kt

@@ -23,14 +23,19 @@ package com.vitorpamplona.quartz.nip51Lists
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.isTagged
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.jackson.EventMapper
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
-import com.vitorpamplona.quartz.nip01Core.tags.events.taggedEvents
+import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.geohash.geohashes
-import com.vitorpamplona.quartz.nip01Core.tags.people.taggedUserIds
-import com.vitorpamplona.quartz.nip01Core.tags.people.taggedUsers
+import com.vitorpamplona.quartz.nip01Core.tags.hashtags.HashtagTag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+import com.vitorpamplona.quartz.nip51Lists.tags.NameTag
+import com.vitorpamplona.quartz.nip51Lists.tags.TitleTag
 import kotlinx.collections.immutable.ImmutableSet
 import kotlinx.collections.immutable.toImmutableSet
 
@@ -43,20 +48,22 @@ abstract class GeneralListEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : PrivateTagArrayEvent(id, pubKey, createdAt, kind, tags, content, sig) {
-    fun category() = dTag()
+) : PrivateTagArrayEvent(id, pubKey, createdAt, kind, tags, content, sig),
+    EventHintProvider,
+    AddressHintProvider,
+    PubKeyHintProvider {
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint) + (cachedPrivateTags()?.mapNotNull(ETag::parseAsHint) ?: emptyList())
 
-    fun bookmarkedPosts() = taggedEvents()
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint) + (cachedPrivateTags()?.mapNotNull(ATag::parseAsHint) ?: emptyList())
 
-    fun bookmarkedPeople() = taggedUsers()
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint) + (cachedPrivateTags()?.mapNotNull(PTag::parseAsHint) ?: emptyList())
 
-    fun bookmarkedPeopleIds() = taggedUserIds()
+    fun name() = tags.firstNotNullOfOrNull(NameTag::parse)
 
-    fun name() = tags.firstOrNull { it.size > 1 && it[0] == "name" }?.get(1)
+    @Deprecated("NIP-51 has deprecated Title. Use name instead", ReplaceWith("name()"))
+    fun title() = tags.firstNotNullOfOrNull(TitleTag::parse)
 
-    fun title() = tags.firstOrNull { it.size > 1 && it[0] == "title" }?.get(1)
-
-    fun nameOrTitle() = name()?.ifBlank { null } ?: title()?.ifBlank { null }
+    fun nameOrTitle() = name() ?: title()
 
     fun filterTagList(
         key: String,
@@ -124,13 +131,13 @@ abstract class GeneralListEvent(
         onReady: (List<Address>) -> Unit,
     ) = privateTags(signer) { onReady(filterAddresses(it)) }
 
-    fun filterUsers(tags: Array<Array<String>>): List<String> = tags.filter { it.size > 1 && it[0] == "p" }.map { it[1] }
+    fun filterUsers(tags: Array<Array<String>>): List<String> = tags.mapNotNull(PTag::parseKey)
 
-    fun filterHashtags(tags: Array<Array<String>>): List<String> = tags.filter { it.size > 1 && it[0] == "t" }.map { it[1] }
+    fun filterHashtags(tags: Array<Array<String>>): List<String> = tags.mapNotNull(HashtagTag::parse)
 
     fun filterGeohashes(tags: Array<Array<String>>): List<String> = tags.geohashes()
 
-    fun filterEvents(tags: Array<Array<String>>): List<String> = tags.filter { it.size > 1 && it[0] == "e" }.map { it[1] }
+    fun filterEvents(tags: Array<Array<String>>): List<String> = tags.mapNotNull(ETag::parseId)
 
     fun filterATags(tags: Array<Array<String>>): List<ATag> = tags.mapNotNull(ATag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/MuteListEvent.kt

@@ -26,9 +26,6 @@ import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.utils.TimeUtils
-import com.vitorpamplona.quartz.utils.bytesUsedInMemory
-import com.vitorpamplona.quartz.utils.pointerSizeInBytes
-import kotlinx.collections.immutable.ImmutableSet
 
 @Immutable
 class MuteListEvent(
@@ -39,39 +36,16 @@ class MuteListEvent(
     content: String,
     sig: HexKey,
 ) : GeneralListEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
-    @Transient var publicAndPrivateUserCache: ImmutableSet<HexKey>? = null
-
-    @Transient var publicAndPrivateWordCache: ImmutableSet<String>? = null
-
-    override fun countMemory(): Long =
-        super.countMemory() +
-            pointerSizeInBytes + (publicAndPrivateUserCache?.sumOf { pointerSizeInBytes + it.bytesUsedInMemory() } ?: 0) +
-            pointerSizeInBytes + (publicAndPrivateWordCache?.sumOf { pointerSizeInBytes + it.bytesUsedInMemory() } ?: 0)
-
     override fun dTag() = FIXED_D_TAG
 
     fun publicAndPrivateUsersAndWords(
         signer: NostrSigner,
         onReady: (PeopleListEvent.UsersAndWords) -> Unit,
     ) {
-        publicAndPrivateUserCache?.let { userList ->
-            publicAndPrivateWordCache?.let { wordList ->
-                onReady(PeopleListEvent.UsersAndWords(userList, wordList))
-                return
-            }
-        }
-
         privateTagsOrEmpty(signer) {
-            publicAndPrivateUserCache = filterTagList("p", it)
-            publicAndPrivateWordCache = filterTagList("word", it)
-
-            publicAndPrivateUserCache?.let { userList ->
-                publicAndPrivateWordCache?.let { wordList ->
-                    onReady(
-                        PeopleListEvent.UsersAndWords(userList, wordList),
-                    )
-                }
-            }
+            onReady(
+                PeopleListEvent.UsersAndWords(filterTagList("p", it), filterTagList("word", it)),
+            )
         }
     }
 

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/PeopleListEvent.kt

@@ -26,9 +26,6 @@ import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.utils.TimeUtils
-import com.vitorpamplona.quartz.utils.bytesUsedInMemory
-import com.vitorpamplona.quartz.utils.pointerSizeInBytes
-import kotlinx.collections.immutable.ImmutableSet
 
 @Immutable
 class PeopleListEvent(
@@ -39,45 +36,6 @@ class PeopleListEvent(
     content: String,
     sig: HexKey,
 ) : GeneralListEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
-    @Transient var publicAndPrivateUserCache: ImmutableSet<HexKey>? = null
-
-    @Transient var publicAndPrivateWordCache: ImmutableSet<String>? = null
-
-    override fun countMemory(): Long =
-        super.countMemory() +
-            pointerSizeInBytes + (publicAndPrivateUserCache?.sumOf { pointerSizeInBytes + it.bytesUsedInMemory() } ?: 0) +
-            pointerSizeInBytes + (publicAndPrivateWordCache?.sumOf { pointerSizeInBytes + it.bytesUsedInMemory() } ?: 0)
-
-    fun publicAndPrivateWords(
-        signer: NostrSigner,
-        onReady: (ImmutableSet<String>) -> Unit,
-    ) {
-        publicAndPrivateWordCache?.let {
-            onReady(it)
-            return
-        }
-
-        privateTagsOrEmpty(signer) {
-            publicAndPrivateWordCache = filterTagList("word", it)
-            publicAndPrivateWordCache?.let { onReady(it) }
-        }
-    }
-
-    fun publicAndPrivateUsers(
-        signer: NostrSigner,
-        onReady: (ImmutableSet<String>) -> Unit,
-    ) {
-        publicAndPrivateUserCache?.let {
-            onReady(it)
-            return
-        }
-
-        privateTagsOrEmpty(signer) {
-            publicAndPrivateUserCache = filterTagList("p", it)
-            publicAndPrivateUserCache?.let { onReady(it) }
-        }
-    }
-
     @Immutable
     class UsersAndWords(
         val users: Set<String> = setOf(),
@@ -88,24 +46,13 @@ class PeopleListEvent(
         signer: NostrSigner,
         onReady: (UsersAndWords) -> Unit,
     ) {
-        publicAndPrivateUserCache?.let { userList ->
-            publicAndPrivateWordCache?.let { wordList ->
-                onReady(UsersAndWords(userList, wordList))
-                return
-            }
-        }
-
         privateTagsOrEmpty(signer) {
-            publicAndPrivateUserCache = filterTagList("p", it)
-            publicAndPrivateWordCache = filterTagList("word", it)
-
-            publicAndPrivateUserCache?.let { userList ->
-                publicAndPrivateWordCache?.let { wordList ->
-                    onReady(
-                        UsersAndWords(userList, wordList),
-                    )
-                }
-            }
+            onReady(
+                UsersAndWords(
+                    filterTagList("p", it),
+                    filterTagList("word", it),
+                ),
+            )
         }
     }
 

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/PrivateTagArrayEvent.kt

@@ -25,6 +25,7 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.nip51Lists.encryption.PrivateTagsInContent
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
@@ -63,7 +64,7 @@ abstract class PrivateTagArrayEvent(
         }
 
         try {
-            Nip51PrivateTags.decrypt(content, signer) {
+            PrivateTagsInContent.decrypt(content, signer) {
                 privateTagsCache = it
                 privateTagsCache?.let { onReady(it) }
             }
@@ -78,7 +79,7 @@ abstract class PrivateTagArrayEvent(
         onReady: (content: String) -> Unit,
     ) {
         privateTags(signer) { privateTags ->
-            Nip51PrivateTags.encryptNip04(
+            PrivateTagsInContent.encryptNip04(
                 privateTags = change(privateTags),
                 signer = signer,
             ) { encryptedTags ->
@@ -97,7 +98,7 @@ abstract class PrivateTagArrayEvent(
         ) {
             if (toPrivate) {
                 current.privateTags(signer) { privateTags ->
-                    Nip51PrivateTags.encryptNip04(
+                    PrivateTagsInContent.encryptNip04(
                         privateTags = privateTags.plus(newTag),
                         signer = signer,
                     ) { encryptedTags ->
@@ -118,7 +119,7 @@ abstract class PrivateTagArrayEvent(
         ) {
             if (toPrivate) {
                 current.privateTags(signer) { privateTags ->
-                    Nip51PrivateTags.encryptNip04(
+                    PrivateTagsInContent.encryptNip04(
                         privateTags = privateTags.plus(newTag),
                         signer = signer,
                     ) { encryptedTags ->
@@ -168,7 +169,7 @@ abstract class PrivateTagArrayEvent(
             onReady: (content: String, tags: Array<Array<String>>) -> Unit,
         ) {
             current.privateTags(signer) { privateTags ->
-                Nip51PrivateTags.encryptNip04(
+                PrivateTagsInContent.encryptNip04(
                     privateTags = privateTags.replaceAll(oldTagStartsWith, newTag),
                     signer = signer,
                 ) { encryptedTags ->
@@ -185,7 +186,7 @@ abstract class PrivateTagArrayEvent(
             onReady: (content: String, tags: Array<Array<String>>) -> Unit,
         ) {
             current.privateTags(signer) { privateTags ->
-                Nip51PrivateTags.encryptNip04(
+                PrivateTagsInContent.encryptNip04(
                     privateTags = privateTags.remove(oldTagStartsWith),
                     signer = signer,
                 ) { encryptedTags ->
@@ -201,7 +202,7 @@ abstract class PrivateTagArrayEvent(
             onReady: (content: String, tags: Array<Array<String>>) -> Unit,
         ) {
             current.privateTags(signer) { privateTags ->
-                Nip51PrivateTags.encryptNip04(
+                PrivateTagsInContent.encryptNip04(
                     privateTags = privateTags.remove(oldTagStartsWith),
                     signer = signer,
                 ) { encryptedTags ->
@@ -224,7 +225,7 @@ abstract class PrivateTagArrayEvent(
             onReady: (content: String, tags: Array<Array<String>>) -> Unit,
         ) {
             current.privateTags(signer) { privateTags ->
-                Nip51PrivateTags.encryptNip04(
+                PrivateTagsInContent.encryptNip04(
                     privateTags = privateTags.remove(oldTagStartsWith),
                     signer = signer,
                 ) { encryptedTags ->
@@ -239,7 +240,7 @@ abstract class PrivateTagArrayEvent(
             signer: NostrSigner,
             onReady: (content: String, tags: Array<Array<String>>) -> Unit,
         ) {
-            Nip51PrivateTags.encryptNip04(
+            PrivateTagsInContent.encryptNip04(
                 privateTags = arrayOf(newTag),
                 signer = signer,
             ) { encryptedTags ->

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/encryption/PrivateTagsInContent.kt

@@ -18,13 +18,13 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.quartz.nip51Lists
+package com.vitorpamplona.quartz.nip51Lists.encryption
 
 import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.jackson.EventMapper
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
 
-class Nip51PrivateTags {
+class PrivateTagsInContent {
     companion object {
         fun decode(content: String) = EventMapper.mapper.readValue<Array<Array<String>>>(content)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/tags/NameTag.kt

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip51Lists.tags
+
+class NameTag {
+    companion object {
+        const val TAG_NAME = "name"
+
+        @JvmStatic
+        fun parse(tag: Array<String>): String? {
+            if (tag.size < 2 || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
+            return tag[1]
+        }
+
+        @JvmStatic
+        fun assemble(name: String) = arrayOf(TAG_NAME, name)
+    }
+}

quartz/src/main/java/com/vitorpamplona/quartz/nip51Lists/tags/TitleTag.kt

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip51Lists.tags
+
+@Deprecated("Use NameTag Instead")
+class TitleTag {
+    companion object {
+        const val TAG_NAME = "title"
+
+        @JvmStatic
+        fun parse(tag: Array<String>): String? {
+            if (tag.size < 2 || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
+            return tag[1]
+        }
+
+        @JvmStatic
+        fun assemble(name: String) = arrayOf(TAG_NAME, name)
+    }
+}

quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/chat/LiveActivitiesChatMessageEvent.kt

@@ -23,10 +23,16 @@ package com.vitorpamplona.quartz.nip53LiveActivities.chat
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
 import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip10Notes.BaseThreadedEvent
+import com.vitorpamplona.quartz.nip18Reposts.quotes.QTag
 import com.vitorpamplona.quartz.nip53LiveActivities.streaming.LiveActivitiesEvent
 import com.vitorpamplona.quartz.utils.TimeUtils
 
@@ -38,7 +44,16 @@ class LiveActivitiesChatMessageEvent(
     tags: Array<Array<String>>,
     content: String,
     sig: HexKey,
-) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+) : BaseThreadedEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    EventHintProvider,
+    PubKeyHintProvider,
+    AddressHintProvider {
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun eventHints() = tags.mapNotNull(ETag::parseAsHint) + tags.mapNotNull(QTag::parseEventAsHint)
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint) + tags.mapNotNull(QTag::parseAddressAsHint)
+
     private fun activityHex() = tags.firstNotNullOfOrNull(ATag::parseAddressId)
 
     fun activity() = tags.firstNotNullOfOrNull(ATag::parse)

quartz/src/main/java/com/vitorpamplona/quartz/nip68Picture/IMetaTagBuilderExt.kt

@@ -28,7 +28,7 @@ import com.vitorpamplona.quartz.nip92IMeta.IMetaTagBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -48,7 +48,7 @@ fun IMetaTagBuilder.mimeType(mime: String) = add(MimeTypeTag.TAG_NAME, mime)
 
 fun IMetaTagBuilder.alt(alt: String) = add(AltTag.TAG_NAME, alt)
 
-fun IMetaTagBuilder.hash(hash: HexKey) = add(HashTag.TAG_NAME, hash)
+fun IMetaTagBuilder.hash(hash: HexKey) = add(HashSha256Tag.TAG_NAME, hash)
 
 fun IMetaTagBuilder.size(size: Int) = add(SizeTag.TAG_NAME, size.toString())
 

quartz/src/main/java/com/vitorpamplona/quartz/nip68Picture/IMetaTagExt.kt

@@ -27,7 +27,7 @@ import com.vitorpamplona.quartz.nip92IMeta.IMetaTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -47,7 +47,7 @@ fun IMetaTag.mimeType() = properties.get(MimeTypeTag.TAG_NAME)
 
 fun IMetaTag.alt() = properties.get(AltTag.TAG_NAME)
 
-fun IMetaTag.hash() = properties.get(HashTag.TAG_NAME)
+fun IMetaTag.hash() = properties.get(HashSha256Tag.TAG_NAME)
 
 fun IMetaTag.size() = properties.get(SizeTag.TAG_NAME)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip68Picture/PictureEvent.kt

@@ -33,7 +33,7 @@ import com.vitorpamplona.quartz.nip92IMeta.imetas
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -68,7 +68,7 @@ class PictureEvent(
 
     private fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
 
-    private fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    private fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     private fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip68Picture/TagArrayBuilderExt.kt

@@ -24,7 +24,7 @@ import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip23LongContent.tags.PublishedAtTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.TitleTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
 
 fun TagArrayBuilder<PictureEvent>.title(title: String) = addUnique(TitleTag.assemble(title))
@@ -43,7 +43,7 @@ fun TagArrayBuilder<PictureEvent>.pictureIMeta(
 
 fun TagArrayBuilder<PictureEvent>.pictureIMeta(imeta: PictureMeta): TagArrayBuilder<PictureEvent> {
     add(imeta.toIMetaArray())
-    imeta.hash?.let { add(HashTag.assemble(it)) }
+    imeta.hash?.let { add(HashSha256Tag.assemble(it)) }
     imeta.mimeType?.let { add(MimeTypeTag.assemble(it)) }
     return this
 }

quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/IMetaTagBuilderExt.kt

@@ -27,7 +27,7 @@ import com.vitorpamplona.quartz.nip92IMeta.IMetaTagBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -47,7 +47,7 @@ fun IMetaTagBuilder.mimeType(mime: String) = add(MimeTypeTag.TAG_NAME, mime)
 
 fun IMetaTagBuilder.alt(alt: String) = add(AltTag.TAG_NAME, alt)
 
-fun IMetaTagBuilder.hash(hash: HexKey) = add(HashTag.TAG_NAME, hash)
+fun IMetaTagBuilder.hash(hash: HexKey) = add(HashSha256Tag.TAG_NAME, hash)
 
 fun IMetaTagBuilder.size(size: Int) = add(SizeTag.TAG_NAME, size.toString())
 

quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/IMetaTagExt.kt

@@ -26,7 +26,7 @@ import com.vitorpamplona.quartz.nip92IMeta.IMetaTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -46,7 +46,7 @@ fun IMetaTag.mimeType() = properties.get(MimeTypeTag.TAG_NAME)
 
 fun IMetaTag.alt() = properties.get(AltTag.TAG_NAME)
 
-fun IMetaTag.hash() = properties.get(HashTag.TAG_NAME)
+fun IMetaTag.hash() = properties.get(HashSha256Tag.TAG_NAME)
 
 fun IMetaTag.size() = properties.get(SizeTag.TAG_NAME)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/VideoEvent.kt

@@ -37,7 +37,7 @@ import com.vitorpamplona.quartz.nip92IMeta.imetas
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -65,7 +65,7 @@ abstract class VideoEvent(
 
     private fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
 
-    private fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    private fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     private fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/FileHeaderEvent.kt

@@ -30,7 +30,7 @@ import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -57,7 +57,7 @@ class FileHeaderEvent(
 
     fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
 
-    fun hash() = tags.firstNotNullOfOrNull(HashTag::parse)
+    fun hash() = tags.firstNotNullOfOrNull(HashSha256Tag::parse)
 
     fun size() = tags.firstNotNullOfOrNull(SizeTag::parse)
 

quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/IMetaTagBuilderExt.kt

@@ -27,7 +27,7 @@ import com.vitorpamplona.quartz.nip92IMeta.IMetaTagBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -47,7 +47,7 @@ fun IMetaTagBuilder.mimeType(mime: String) = add(MimeTypeTag.TAG_NAME, mime)
 
 fun IMetaTagBuilder.alt(alt: String) = add(AltTag.TAG_NAME, alt)
 
-fun IMetaTagBuilder.hash(hash: HexKey) = add(HashTag.TAG_NAME, hash)
+fun IMetaTagBuilder.hash(hash: HexKey) = add(HashSha256Tag.TAG_NAME, hash)
 
 fun IMetaTagBuilder.size(size: Int) = add(SizeTag.TAG_NAME, size.toString())
 

quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/TagArrayBuilderExt.kt

@@ -25,7 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.FallbackTag
-import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.ImageTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MagnetTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -41,7 +41,7 @@ fun TagArrayBuilder<FileHeaderEvent>.url(url: String) = add(UrlTag.assemble(url)
 
 fun TagArrayBuilder<FileHeaderEvent>.mimeType(mimeType: String) = add(MimeTypeTag.assemble(mimeType))
 
-fun TagArrayBuilder<FileHeaderEvent>.hash(hash: HexKey) = add(HashTag.assemble(hash))
+fun TagArrayBuilder<FileHeaderEvent>.hash(hash: HexKey) = add(HashSha256Tag.assemble(hash))
 
 fun TagArrayBuilder<FileHeaderEvent>.fileSize(size: Int) = add(SizeTag.assemble(size))
 

quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/HashSha256Tag.kt

@@ -20,14 +20,14 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
-class HashTag {
+class HashSha256Tag {
     companion object {
         const val TAG_NAME = "x"
         const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
             return tag[1]
         }
 

quartz/src/main/java/com/vitorpamplona/quartz/utils/Ensure.kt

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.utils
+
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+@OptIn(ExperimentalContracts::class)
+inline fun ensure(
+    condition: Boolean,
+    exit: () -> Nothing,
+) {
+    contract {
+        returns() implies condition
+    }
+    if (!condition) exit()
+}

quartz/src/main/java/com/vitorpamplona/quartz/utils/Hex.kt

@@ -21,24 +21,25 @@
 package com.vitorpamplona.quartz.utils
 
 object Hex {
-    private val lowerCaseHex = arrayOf('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f')
-    private val upperCaseHex = arrayOf('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F')
+    private const val LOWER_CASE_HEX = "0123456789abcdef"
+    private const val UPPER_CASE_HEX = "0123456789ABCDEF"
 
     private val hexToByte: IntArray =
         IntArray(256) { -1 }.apply {
-            lowerCaseHex.forEachIndexed { index, char -> this[char.code] = index }
-            upperCaseHex.forEachIndexed { index, char -> this[char.code] = index }
+            LOWER_CASE_HEX.forEachIndexed { index, char -> this[char.code] = index }
+            UPPER_CASE_HEX.forEachIndexed { index, char -> this[char.code] = index }
         }
 
     // Encodes both chars in a single Int variable
     private val byteToHex =
         IntArray(256) {
-            (lowerCaseHex[(it shr 4)].code shl 8) or lowerCaseHex[(it and 0xF)].code
+            (LOWER_CASE_HEX[(it shr 4)].code shl 8) or LOWER_CASE_HEX[(it and 0xF)].code
         }
 
     @JvmStatic
     fun isHex(hex: String?): Boolean {
-        if (hex.isNullOrEmpty() || hex.length and 1 != 0) return false
+        if (hex.isNullOrEmpty()) return false
+        if (hex.length and 1 != 0) return false
 
         try {
             for (c in hex.indices) {